The following story offers a humble example of islands as natural laboratories, stressing the significance of insights gained from free-ranging animals in a somewhat simplified context. Two generous data-sharing populations of promiscuous sexually coercive Hermann's tortoises (Testudo hermanni, a species with delayed maturity [~10 years]) from the Prespa Lake Region in Macedonia were scrutinized. Comparisons between island (Golem Grad, divided into narrow shores and a large plateau) and mainland (Konjsko) populations revealed age-specific life-history trends and behavioural peculiarities. The island context brought to attention very unusual demographic processes, eventually resonating with a seemingly inevitable population doom brought upon by insufferable sexual conflict.

Neonates to three-year old tortoises exhibit slow growth and low variation in body size (VBS) among individuals, likely illustrating the impact of a soft shell and lack of parental care. The subsequent gradual approach of a survival plateau (annual survival rate increase: 0.30 to 0.70) parallels a gradual increase in confidence and a slowly hardening shell that promotes better foraging capabilities reflected onto a phase of fast linear growth. Unlike long-lived mammals that are in a hurry to reach maturity at a certain size (lowering VBS) that will increase survival and ensure reproduction during a non-growing adult phase, tortoises have the potential for indeterminate growth (estimated individual asymptotic sizes from incremental growth after maturity on Golem Grad range from ~153 to ~224). When protected by a hard carapace that translates into a survival plateau (0.90) at the age of five, indeterminate growth leaves room for young tortoises to express individuality in growth regimes, promoting an ever increasing VBS prior to adulthood. Size-at-maturity is thus a blurred notion in these tortoises. Testosterone levels and sexual activity indicate that minimal size at maturity in precocious males is somewhere between 115-120mm straight carapace length (SCL), whereas VBS and literature point to a range of 140-150mm. Clearly some tortoises mature early, while others are in no

ISLANDS AS VECTORS OF INSIGHT

rush at all. Sexual size dimorphism in the Testudo genus suggests most larger-atmaturity tortoises are likely females; Golem Grad population-mean female asymptotic size estimates make no exception.

Nevertheless, actual body sizes on the island do not reflect estimates from incremental growth -the largest individuals are males. At ~100 individuals/ha with an operational sex ratio (OSR [♂/♀]) of ~11, male sexual coercion from constantly aroused tortoises drastically increased female mating costs, wreaking havoc on Golem Grad. Adult survival estimates are considerably higher in males (0.97) than in females (0.84). This is accompanied with low female bodycondition, intense cloacal injuries inflicted by males, that can even push females from the island's high cliffs. Overall, island females do not live long and are also discouraged from reproduction (dissections data). Even implementing species' average fecundity, simulations predict recruitment insufficiency and a decline in the number of females, exacerbating OSR-bias. Tortoises are long-lived animals; adult cohorts ensure population growth despite environmental fluctuations.

Nevertheless, on the island the temporal-variance of adult female survival has succumbed to the pressure stirred up by male sexual coercion and will likely lead to population extinction. Perhaps most surprisingly, cloacal injuries indicate that even immature females (~8 years old) have become the target of the maladaptive sexual appetite of males. After reaching nine years, females that inhabit the island's macho Plateau (only 5% of adults are females) are harassed and exhibit lower average annual survival probabilities. This unfortunate demographic drift does not seem to be the only consequence of OSR bias and high density -island frustrated males court and mount other males more frequently than females. They even exhibit extravagant sexual behaviours, attempting to copulate with dead conspecifics, empty shells, and stones. Golem Grad tortoises elucidated the first natural example of a "prison effect," whereby a high population density combined with female deprivation (but not accompanied with abnormal testosterone levels) triggered same-sex sexual behaviours (SSB) as a mere outlet of sexual stimulation. More generally, this supports the hypothesis that SSB can be a nonadaptive consequence of unusual proximate factors rather than reflecting physiological disorders. Finally, SSB may even benefit females by diluting aggressive male mounting efforts among males as well.

In light of the expensive conservation endeavours on the endangered Hermann's tortoises in western Europe, life-history insight gained from Golem Grad tortoises can provide a valuable conservation lesson: taking into account Hermann's tortoises' environmental sex determination, captive breeding programs can easily create dense female biased colonies that will stand the best chance of creating a prosperous breeding population in the shortest time. Such valuable advice can reduce conservation costs, and help reverse the artificial separation of fundamental research from conservation, particularly evident in the developing (e.g. Macedonia) and third world. After all, applied conservation should only be the inevitable and likely unavoidable side-effect of research, rather than a short term must! Une dérive de la vie de tous les jours vers la brutalité sexuelle : chroniques d'une population de tortues surexcitées Ce manuscrit illustre modestement en quoi les îles sont des laboratoires naturels utiles à la recherche grâce à leur nature simplifiée. Deux populations de tortues d'Hermann (Testudo hermanni) nous ont fourni des données denses sur la démographie et les comportements d'un organisme à maturité sexuelle tardive (~10 ans) et au système d'appariement coercitif. Dans la région du lac Prespa en Macédoine, nous avons comparé une population insulaire (Golem Grad, avec des rivages étroits et un plateau) avec une population continentale (Konjsko). Les analyses des variations des traits d'histoire de vie au cours de la croissance et selon le sexe ont révélé des surprises. Dans le contexte insulaire, une dérive démographique causée par les comportements sexuels des mâles conduit la population vers l'extinction ; il s'agit du premier cas décrit en conditions naturelles.

De la naissance jusqu'à l'âge de trois ans, les tortues grandissent lentement et au même rythme, probablement à cause de l'absence de soins parentaux et de la faible protection de la petite carapace qui canalisent les variations. Ensuite, la valeur protective de la carapace augmente, ce qui ouvre différentes options alimentaires, accompagnées par une accélération de la croissance et de la survie (de 0.3 à 0.7). Contrairement aux mammifères qui sont sous forte pression pour atteindre le plus vite possible la maturité, ce qui brime les variations interindividuelles de croissance et de taille, les jeunes tortues qui peuvent grandir toute leur vie expriment davantage de variations. Les estimations de taille asymptotique calculées grâce aux nombreuses recaptures au cours des années s'étalent alors de 154mm à 224mm pour la longueur. Une fois les tortues protégées par une solide carapace, dès 5 ans, les taux de survie plafonnent à des valeurs élevées (0.9). La très longue croissance continue laisse alors la place pour de multiples trajectoires, ce qui amplifie encore les divergences interindividuelles avant et aspres la maturité. L'existence d'une taille exacte à maturité est une notion floue chez cette espèce. D'ailleurs, les taux de testostérone et d'activité sexuelle montrent que la maturité des individus précoces oscille entre 115mm et 120mm alors que la littérature propose 140mm à 150mm. Cet écart s'explique par le fait que certaines tortues deviennent adultes tôt tandis que d'autres non.

Dans le genre Testudo, Le dimorphisme sexuel de taille penche vers les femelles ; les estimations de taille asymptotique moyenne de nos deux populations sont conformes à cette règle. Les femelles sont plus grandes que les mâles à Konjsko, mais pas sur Golem Grad. Un processus doit empêcher les femelles insulaires de grandir pleinement.

Sur Golem Grad, avec environ 100 individus/ha et un sexe ratio opérationnel fortement biaisé (OSR : ♂/♀ ~11), les mâles harassent les femelles continument et créent des ravages dans la population. La survie des mâles adultes est élevée (0.97) alors que celle des femelles est anormalement basse (0.84). Les femelles sont amaigries, souffrent de blessures cloacales, et sont même précipitées des falaises par les mâles surexcités. Sur l'ile les femelles ne vivent pas longtemps et n'arrivent pas assez souvent à produire des oeufs (données de dissection). Même en implémentant une fécondité moyenne pour l'espèce dans les modèles, les simulations prédisent un recrutement trop faible, un déclin du nombre de femelles, ce qui induit un cercle vicieux en exagérant le biais du sexe ratio et le taux d'harassement.

Les tortues sont des animaux longévifs, la stabilité des paramètres démographiques des cohortes adultes assure la viabilité des populations en dépit de fluctuations environnementales. Mais sur l'île, la variance temporelle de la survie des femelles adultes est fortement secouée par les assauts des mâles, ce qui peut entrainer l'extinction de la population. Cette violence comportementale touche même les immatures (~8 ans) qui victimes de l'appétit sexuel et mal dirigé des mâles montrent des blessures cloacales. La survie des femelles de plus de neuf ans, cernées par les mâles (5% de femelles adultes sur le plateau), décroit.

Cette dérive démographique, conséquence d'une forte densité combine à un fort biais du sexe ratio, entraine aussi une forte expression de comportements homosexuels parmi les mâles frustrés. Ces derniers montrent des comportements sexuels exubérants, ils montent des cadavres de tortues, des carapaces vides, des pierres. Golem Grad apporte le premier exemple de "l'effet prison" en conditions naturelles, où une forte densité de population associée à une manque de partenaires sexuels déclenche de nombreux comportements homosexuels, exutoires d'une tension sexuelle, indépendamment d'une quelconque anomalie hormonale. D'une façon globale, ces résultats étayent l'hypothèse non-adaptative des comportements homosexuels comme simple conséquence de facteur proximaux sans impliquer de désordres physiologique. Peut-être que ces comportements homosexuels épargnent aussi les femelles.

Compte tenu des efforts à fournir pour préserver les populations de tortues d'Hermann qui sont menacées en Europe occidentale, nos résultats pourraient être utiles. Grâce à la détermination par la température d'incubation du sexe des tortues d'Hermann, des programmes d'élevage pourraient livrer de grandes quantités de femelles pour repeupler les populations fragilisées en limitant les coûts infligés par les mâles. Cette approche permettrait de réduire les coûts logistiques. Elle montre aussi la perméabilité entre les approches fondamentales et pratiques de la conservation ; notion qu'il faut injecter dans les pays en voie de développement (e.g. Macédoine). La conservation appliquée devrait d'ailleurs être considérée comme une production naturelle de la recherche.

Islands act as a binding agent of the diverse subject matters this thesis deals with, and I can draw a strong parallel between the diversity of written subject matters and the diverse nature of the benefits I have acquired from one island in particular, Golem Grad in Prespa Lake, Macedonia. Thus, I would like to primarily express my most honest gratitude to its existence, for neither this PhD as the current crown of my biological knowledge would've materialized, nor a significant portion of my emotional personal connections that have moulded me in the human I am now. Dozens of those connections I am thankful to, but few cannot go unmentioned. Ljiljana Tomović and Xavier Bonnet did an impeccable job at supervising this thesis by providing me with ample freedom and guidance that nourished my creativity. But above all else, even before this thesis they were my friends, and I couldn't have done it without the countless hugs I have received from the both of you. There are no words that can express my most sincere gratitude, but I believe it mostly boils down to: I love you guys! Xavier, it truly isn't the end of the world and thank you so much for teaching me that valuable lesson. Lili I have become an addict of our "кокошкатања" и нашето пријателство ми е една од најдрагоцените работи во овој живот! Ana Golubović, you were the silent supervisor of this thesis. Your scientific creativity filled in many crucial blanks in this work, which has in turn increased its quality substantially. But most importantly, your extensive field presence and shared love of Golem Grad filled the time spent together in the field with priceless laughter and joy, but also perfectly timed accommodating silence accompanied with only the sounds and vistas of Prespa. I thank you for everything! I wish to thank my family that I deeply love. Besides perhaps at times having a hard time understanding my love of a tortoise and viper infested deserted island, my parents still provided unconditional love and support, and found joy in my success. I want to thank my sister for always making it clear how fortunate I am to know my explicit passion and being in awe of my drive and work. Even more importantly, thank you for bringing Isijan and Anika to this world! Nothing would make me happier than to help them find their drive, and explicit passion and love in life.

The winters spent in Chizé during this thesis were incredibly productive, but also incredibly challenging, because of my social cravings. I thank everyone who was my friend there, but three people and one dog are most responsible for maintaining my sanity. The humans Loriane Mendez and Rui Catarino and the Belgian Shepherd Largo offered countless hours of conversation, hugs and meals in our shared living spaces and I love you guys for that and for so much more. I have to thank Héloiese Guillot, for without her being the fun and insightful officemate she was for the first couple of years, but especially during my first months in Chizé I would've most likely completely lost it.

I wish to thank all the rest of my friends from around the world and back home -srcinja, you very well know who you are and therefore you very well know that naming names will significantly contribute to the page count of this section. All that matters is that you people have made my life the exciting little piece of "being" that it is and so have contributed immensely to my general happiness and therefore productive work during this thesis. I love you intensely! Last but surely not least, some of the "controversial" subjects of this thesis attracted media coverage, which I appreciate, but am not always the fondest of.

Nevertheless, facilitated by such coverage, what I can only believe to be a product of serendipity took place -I met my partner. Ivo Kunovski thank you for being the most humble, loving person I have ever met and thank you for loving me with such intensity. I cannot anymore imagine my life prior to meeting you, and I cannot imagine my future life without you. I have never felt a bigger quantity of condensed love in the amount of time we have spent living together and apart, and I cannot wait to experience the love that life has in store for us.

Thank you to everyone who has ever loved me.

Dragan strict protection? The case of Testudo hermanni boettgeri from the central Balkans ..... 1.1.6.1 Sexual behaviours .................................................................................. 1.1.6.2 Male maturity ....................................................................................... 1.1.7 "The environment is a kind of container, and life is like a liquid that adapts to fill it" [START_REF] Clancy | Survival of the Friendliest[END_REF]; "current biodiversity seems to simply be the consequence of a collection of fortuitous events that have fallen victims to a plethora of evolutionary processes". These are two statements that, prior to writing this thesis I believed summarize in a very broad sense the subject matter of the written word to follow. At present day perspective these sentiments not only sum up my subject matter in a broad sense, but perhaps the entire field of evolutionary biology, 'and then some'. I find them nonetheless true and fitting, since they simplify very complicated concepts, and additionally, since I believe every endeavour can benefit from fortuity, particularly serendipitous fortuity.

BROAD

Studying the product of fortuity would itself require a collection of fortuitous events, thus simplification opportunities are welcome. Isolated geographical areas i.e. islands in the broad sense (e.g. lakes are considered terrestrial analogues to islands [START_REF] Fryer | Endemism, speciation and adaptive radiation in great lakes[END_REF]) offer exactly that. Going back to the first statement, if we imagine the environment to be a kind of container than we can imagine islands to be very well disjointed segments of that container sustaining fewer 'liquids' than the rest. The potential implications that come with this scenario offer extraordinary opportunities to gain:

-thorough insight on the isolated island inhabitants thanks to the lack of certain confounding factors and contingencies ('fewer liquids') i.e. islands as facilitators of (run-of-the-mill) biological insight enquiry, or -some details of the peculiarities (flukes and quirks; fortuitous events themselves) that often arise from the exposure to disjointed-areaspecific factors that due to their simplicity and isolation can perhaps lack factors of stabilization i.e. islands as vectors of peculiarities.

The former can be very beneficial, getting us closer to the identification of general laws in ecology and sometimes their general extrapolation [START_REF] Lawton | Are There General Laws in Ecology?[END_REF], whereas the second one is overwhelmingly exciting since it offers a glimpse at the potential that has been hidden and overlooked in open environments. While extrapolation can obviously be immensely beneficial, such as in the context of efficient conservation policies and programs, unique peculiarities (while not necessarily easy to extrapolate) are some of the facets of the variation necessary to sustain diversity and evolution. After all, if such variation is fortuitously better adapted to an ever-changing environment, it can morph into the new consistent phenotype. Witnessing (i.e. capturing instances of fortuity) is, in my opinion, the closest a biologist can come to the broadly used, but in my book controversial term -a blessing. During the following work I will make an attempt at unravelling the broadness of the preceding statements into examples from literature, details from my team's own work and finally a conclusion. Though any example can be perceived as underwhelming superimposed against seemingly endless variation, we know of no better way of untangling it.

While running the risk of adding a strong taste of cliché to this thesis, any subject combining islands, biodiversity, ecology and evolution cannot be approached without mentioning the Galapagos Archipelago, Charles Darwin or at least Rosemary and Peter Grant. While Darwin was the first to formally pioneer the idea of evolution through natural selection [START_REF] Darwin | Origin of the Species[END_REF], the Grants have managed to capture some of the processes underlying natural selection in exhaustive work (from genetics to ecology) dealing with the 14 species of Galapagos finches [START_REF] Grant | What Darwin's Finches Can Teach Us about the Evolutionary Origin and Regulation of Biodiversity[END_REF]. During their four decadeslong work they have explicitly demonstrated how the environment is like a container ('box' in their words) that finches continuously try to adapt to. The word 'continuously' is crucial in this context since in the past 2-5 million years that finches have been inhabiting the archipelago, the islands' environments have changed dramatically. Not only have droughts and wet seasons interchanged repeatedly, moulding the environment, but also due to their volcanic origin new islands have formed and old ones have shrunk or sank.

Thus, not only is life like a liquid, but the containers are not completely solid either. The Galapagos Islands are still changing very rapidly and the Grants (2003) have captured fortuitous moments of dispersal and speciation within and between islands and have been able to follow these processes throughout.

Witnessing the first settlers of a population of a species previously only present as a vagrant on an island, and subsequently monitoring each coming generation [START_REF] Grant | A population founded by a single pair of individuals: Establishment, expansion, and evolution[END_REF] while also monitoring cohabitants and environmental parameters likely falls more so in the ballpark of serendipity. I believe a 2006 report [START_REF] Grant | Evolution of Character Displacement in Darwin's Finches[END_REF] on the finches of the small Galapagos island of Daphne major to epitomize this occurrence, exemplifying both character release and character displacement phenomena. The former is hypothesized to have pushed the medium ground finch (Geospiza fortis) into exploiting the locally abundant small seeds by evolving smaller beak sizes (smaller seeds are preferred when abundant due to a tradeoff in the energetic rewards between feeding on small and large seeds [START_REF] Benkman | Food Profitability and the Foraging Ecology of Crossbills[END_REF]) in the absence of the smaller ground finch that would otherwise compete for that resource. Nevertheless, larger seeds were still present sustaining some larger G. fortis individuals among the smaller ones. A drought in 1977 caused a scarcity in small seeds, favouring large finch survival and decimating the numbers of smaller ones. A subsequent El Niño event brought plentiful rainfall renewing small and large seedbanks on the island, but also creating favourable conditions for the occasional vagrant large ground finches (Geospiza magnirostris) to stay and breed (two females and three males in 1982). Character displacement did not become evident while large seeds were abundant, but once another drought took place in 2004, the then plentiful G. magnirostris, which is much better adapted at exploiting large seeds and simply eats more of them, took over.

Unlike the event of 1977, this time, larger G. fortis stood very little chance and the species had to make ecological adjustments to their larger and hungry competitors. Interestingly, although speciation is a neverending process, frequent perturbations in the Galapagos environments (e.g. El Niño/La Niña events) seem to have made it faster than usual -most lineages of finches on the archipelago still interbreed [START_REF] Lamichhaney | Evolution of Darwin's finches and their beaks revealed by genome sequencing[END_REF]. Additionally, population mean beak shape and size from a few decades ago when the studies started are significantly different from recent measurements in the same taxa [START_REF] Grant | What Darwin's Finches Can Teach Us about the Evolutionary Origin and Regulation of Biodiversity[END_REF].

Jonathan Losos and his collaborators have used island systems extensively over the years to study the ecology and evolution of lizards and offer another prime example of fortuity in a recent report. Namely, [START_REF] Donihue | Hurricane-induced selection on the morphology of an island lizard[END_REF] demonstrated for the first time that hurricanes can cause selective mortality on the basis of phenotypic traits. The team surveyed the morphology of the endemic Anolis scriptus on the Turks and Caicos Islands (Water Cay and Pine Cay), but did not anticipate the forthcoming record-breaking storms -hurricanes Irma and Maria (with wind speeds of up to 200 and 240 km/h, respectively). Going back to the islands post storm and resurveying the same transects revealed evolution by natural selection in action, more specifically directional selection. The authors quantified significant morphological changes on both islands linked to improved clinging ability (larger toepads [START_REF] Crandell | Stick or grip? Co-evolution of adhesive toepads and claws in Anolis lizards[END_REF], proportionately longer humeri [START_REF] Kolbe | Effects of Hind-Limb Length and Perch Diameter on Clinging Performance in Anolis Lizards from the British Virgin Islands[END_REF]] and shorter femurs [START_REF] Donihue | Hurricane-induced selection on the morphology of an island lizard[END_REF]) and found a significant decrease in variance within the succeeding samples (indicating directional selection).

Cases of fast evolutionary change and the questionable species statuses of Galapagos finches beg the question of determinism in evolution. Anolis lizard communities from the Caribbean have seemingly remained unchanged since the Miocene [START_REF] Sherratt | Amber fossils demonstrate deep-time stability of Caribbean lizard communities[END_REF]. Interestingly, these communities of lizards occupy all the great Antilles, but habitat specialists (ecomorphs) are genetically distant between islands [START_REF] Losos | Contingency and determinism in replicated adaptive radiations of island lizards[END_REF]. It seems that communities remain the same between islands and geological time, but not genetic lineages (ruling out vicariance as the driver of these examples). Furthermore, replicate adaptive radiations between islands imply adaptation as the main culprit for this outcome, rather than constraint. Galapagos finches seem to follow similar adaptive tendencies constantly evolving beak size and shape, but unlike Caribbean anoles they still fail to form distinct genetic lineages keeping their species status questionable. This might be a result of either their much higher dispersive capabilities, or the sheer frequency of environmental vagaries; nonetheless neither is as relevant to this thesis as are the most prominent common denominators of the afore-mentioned examples -islands and the quantum and quality of data collection they offer. These little containers holding often simplified, or at least smaller pieces of environment clearly present researchers with the highest level of detectable fortuitous events offering much convenience for proper evolutionary-ecological data collection.

Unquestionably, experimental laboratory research is technically the safest way of drawing causal conclusions since contingencies can be heavily controlled, but natural systems are full of contingencies. Thus, dense long-term datasets from free-ranging animals offer invaluable insight on population functioning.

Repeated species-specific studies can further overcome bias from confounding factors and bring about sound conclusions with species-wide relevance. On the other hand, controlled experiments also offer indispensable insight and replicates make for more solid conclusions, but the scope can be narrow (nevertheless, this is still the best way of uncovering the genetic architecture and/or physiological processes underlying phenotypes). Laboratory and field studies on lizards from the Dalmatian coast offer a glance into the benefits and shortcomings of both approaches. Field effort demonstrated the existence of three colour morphs (orange, yellow and white) of the Dalmatian Wall lizard (Podarcis melisellensis) on the island of Lesnovo in Croatia, and differentiated the orange morph as longest (snout-vent length) and with a disproportionately large head [START_REF] Huyghe | Morphology, performance, behavior and ecology of three color morphs in males of the lizard <i>Podarcis melisellensis<i[END_REF]. It was only later, after more in-depth laboratory measurements that the orange morph revealed a harder bite force which was linked to larger internal and external jaw adductors [START_REF] Huyghe | It is all in the head: morphological basis for differences in bite force among colour morphs of the Dalmatian wall lizard[END_REF]; even later, molecular analyses showed that the three colour morphs may represent weakly distinct gene pools, possibly indicating assortative mating [START_REF] Huyghe | Genetic divergence among sympatric colour morphs of the Dalmatian wall lizard (Podarcis melisellensis)[END_REF]) and opening even more exciting areas for future research. Close by, on a smaller Dalmatian island [START_REF] Herrel | Rapid large-scale evolutionary divergence in morphology and performance associated with exploitation of a different dietary resource[END_REF] demonstrated that, after outcompeting the native Dalmatian wall lizard and causing its local extinction, the introduced Italian Wall lizard (Podarcis sicula) shifted to a predominantly plant-based diet and in a matter of only 36 years (~30 generations) went through a dramatic evolutionary event of intestinal morphology. Namely, unlike their nearby, predominantly carnivorous population of origin, these lizards' necessity to tear and digest more cellulose brought about their higher bite force and the presence of cecal valves that slow down food passage, allowing for fermentation processes that break down cellulose. Cecal valves are absent from known conspecifics, but their presence in hatchlings and juveniles of this population suggests a genetic basis. Nevertheless, the authors point out the necessity of future controlled laboratory investigations on the potential roles of maternal effects and/or phenotypic plasticity in the divergence between populations.

Although, what is the appropriate sample to study phenotypic plasticity? - [START_REF] Gianoli | Studying phenotypic plasticity: the advantages of a broad approach[END_REF] state: "advances in the understanding of the ecological significance of phenotypic plasticity in nature can be achieved if representative samples of the genotypic diversity of natural populations are included in the study". They build this argument on top of the ongoing debate over the use of clones (or genetic families) across ecological gradients when studying plasticity. While this is the cleanest approach regarding confounding factors, it also offers less reliable results to be discussed in the context of nature.

Indeed, "only a small number of original genotypes would be sampled in the field" [START_REF] Gianoli | Studying phenotypic plasticity: the advantages of a broad approach[END_REF]. Drawing a parallel between samples collected for experiments vs. their native population and island populations vs. other conspecific populations paints the idea of islands as "natural laboratories" -"places where one can find numerous experiments in progress at any time" [START_REF] Wallace | Social Behavior on Islands[END_REF]. If the marriage of controlled laboratory experiments and those based in nature can give the most objective insight, then islands may well be their lovechild of compromise.

The island of interest to the thesis at hand -Golem Grad has already presented its role as a natural laboratory. The local dense population of dice snakes (Natrix tessellata) allowed for the collection of more than 5,000 individuals in four years [START_REF] Ajtić | Unexpected life history traits in a very dense population of dice snakes[END_REF]. These data provided biological and ecological insight: known maximal body size (at the time) was extended by ~20%, maturity was reported to be attained at a longer snout-to-vent length, and a co-occurrence of three constantly present colour morphs in both sexes was documented. Interestingly, Ajtić. et al. (2013) suggested a very fast recruitment rate due to low numbers of subadults, making Golem Grad an ecosystem more to the likes of tropical systems (for dice snakes). On another note, that is -on-another-island-dwelling-water-snake-species-from-the-New-World, the Northern Water Snake (Nerodia sipedon insularum), islands have further demonstrated the levels of convenience they offer to the amassment of data and insight. Specifically, unlike Golem Grad dice snakes, Water Snakes inhabiting western Lake Eire's island region are slower growers than other conspecifics [START_REF] King | Population Ecology of the Lake Erie Water Snake, Nerodia sipedon insularum[END_REF]), but similar "showers" as Golem Grad dice snakes (e.g. three insular colour morphs, King R.B. 1987).

Such studies have allowed for the detection of high variation within traits and on several levels of organization, notably inter-individual growth divergence within Water Snakes (King et al. 2016). While population mean trait values are informative, the authors demonstrated that variation among individuals is so high that some asymptotic size projections fall out of population means. Islands facilitate the long-term continuous annual recaptures and measurements of individuals, crucial for individual-based models. In light of the ever-growing awareness of the importance of individual heterogeneity to detailed and ever less biased ecological and evolutionary studies [START_REF] Hamel | Introduction to: Individual heterogeneity -the causes and consequences of a fundamental biological process[END_REF], future effort should be allocated to such capture-recapture (CR) studies. These notions are of particular importance to the understanding of different facets of life history theory, particularly having in mind the huge variety of traits, their common correlative nature (e.g. body size has a ubiquitous effect on other traits [START_REF] Peters | The ecological implications of body size[END_REF]) and finally the resulting broad spectrum of animal lifehistories. Broad categories have been developed according to common trait covariation such as the slow-fast continuum of life-history tactics, or longand short-lived animal life histories [START_REF] Stearns | The Evolution of Life Histories (1 edition)[END_REF]. Nevertheless, as helpful as broad definitions and categories are, they cannot embrace the full complexity of the processes under focus and they may mistakenly clump organisms or individuals together promoting errors; identifying (individual) heterogeneity and implementing it into the definition of finer life-history categories will be useful.

Although broad and complex to begin with, [START_REF] Sol | Integrating behavior into life-history theory: a comment on Wong and Candolin[END_REF] argue, convincingly so, the necessity of further integrating life-history theory in a behavioural framework with the goal of a more unified theory. Indeed, [START_REF] Wong | Behavioral responses to changing environments[END_REF] demonstrate that understanding behavioural responses can help anticipate the impact that human-induced environmental change can have on populations, communities and ecosystems. Behavioural phenomena are nevertheless often open to interpretation, and furthermore due to the vastness of some ecosystems and the timid nature of many living organisms also difficult to witness. Amassing behavioural observations in order to identify patterns is thus usually an exceptionally ungrateful task, making islands adequate vectors for observation due to (often) easier data collection [START_REF] Wallace | Social Behavior on Islands[END_REF]. This is to a big extent likely a consequence of island tameness due to lack of exposure and/or predation [START_REF] Cooper | Island tameness: living on islands reduces flight initiation distance[END_REF][START_REF] Rasheed | Persistence of antipredator behavior in an island population of California quail[END_REF], a phenomenon even Darwin himself observed ("a gun is here [Galapagos] almost superfluous") after pulling iguana tails and sitting on giant tortoises. This notion is often contested by the theory of a founder effect initiated by bold dispersal-prone individuals that are likely the first and/or the most common colonizers [START_REF] Cote | Personality traits and dispersal tendency in the invasive mosquitofish (Gambusia affinis)[END_REF][START_REF] Brodin | Personality trait differences between mainland and island populations in the common frog (Rana temporaria)[END_REF]. Regardless, Golem Grad Island has already managed to provide sufficient dense behavioural observations to study even such phenomena. Golubović et al. (2013a[START_REF] Golubović | Variations in righting behaviour across Hermann's tortoise populations: Righting behaviour in Hermann's tortoise[END_REF] demonstrated that habitat and behaviour correlate nicely, tortoises exposed to the rugged island landscape being much more prone to risk-taking behaviour and encouraged to overcome obstacles than genetically hardly distinguishable (unpublished data) mainland (Konjsko village, Macedonia) conspecifics. Interestingly, some insular birds are known to tone down their songs [START_REF] Grant | Plumage and the Evolution of Birds on Islands[END_REF][START_REF] Fitzpatrick | Intraspecific Variation in Wing Length and Male Plumage Coloration with Migratory Behaviour in Continental and Island Populations[END_REF][START_REF] Roulin | Insularity and the evolution of melanism, sexual dichromatism and body size in the worldwide-distributed barn owl[END_REF] and others even their plumage [START_REF] Hamao | Simplified song in an island population of the bush warbler Cettia diphone[END_REF][START_REF] Baker | Differing effects of isolation on evolution of bird songs: examples from an island-mainland comparison of three species: Differentiation Of Island Bird Songs[END_REF], both likely the result of changing sexual selection pressure (Andersson M.B. 1994).

Finally, besides my primary interest in fundamental research due to sheer curiosity, its application is inevitable and brings a profound sense of satisfaction when applied to successful conservation. A system bordering Golem Grad Island's host lake of Lake Prespa -Lake Mikri Prespa in Greece tells one such story. Until the end of the previous century the region faced constant changes in human population and local agricultural and farming practices [START_REF] Catsadorakis | Conservation and management issues of Prespa National Park[END_REF]. This affected the local environment drastically by reducing the surface area of wet meadows around the lake precluding some birds from breeding completely (e.g. Glossy Ibis), or simply lowering their numbers (e.g. Dalmatian pelican, pygmy cormorant, heron species, the ferruginous duck etc.). Sometimes conservation measures like reintroductions seem straightforward, but systematic research can point out crucial, but often not obvious effects. For example, [START_REF] Bertolero | The importance of including survival release costs when assessing viability in reptile translocations[END_REF] describe a release cost to the survival of Hermann's tortoises introduced to an already present population. Such insight might primarily even seem obvious or unnecessary, but it can easily make the difference between life and death and prevent fates such as the ones of the Eastern black rhinos.

Activities of the

An ancient Hindu text, the Bhogala Purāna states: "The tortoise bears the burden of the whole world." While in its literal sense this is a gross overestimation, I can confidently say that a couple of thousand tortoises from Golem Grad, Macedonia do bare a big part of the burden of this thesis. The island nature of this population has facilitated the amassment of dense individual CR datasets of tortoises of all ages, spanning the bigger part of the population. At the naive beginning of my endeavours on Golem Grad (in 2009) I wanted to learn and know everything. As more experience and extra knowledge accumulated my eyes were opened to everyday limitations due to the lack of resources, difficult logistics and sometimes simply disappointment and lack of motivation. If the last one prevails it can have dangerous consequences, but when the three are simultaneously taken into account in the presence of a very generous datasharing system, then relevant but reasonable questions materialize.

At the very beginning of this thesis, inquiry into a tortoise's extremely delayed maturity started to take the form of several small questions. Notably, what do the terms "juvenile" or "subadult" entail during (almost) a decade of immature life? -in this manuscript the issue will be approached via variation exploration of selected life-history traits and sexual hormones. Growth and body size, survival, and testosterone levels will be explored on an individual-and population-mean scale, but most importantly, with age-specific considerations.

As for adult sexually mature tortoises, seemingly common same-sex sexual behaviours (SSB) among males piqued researchers' curiosities initiating the exploration of proximal and ultimate causes of SSB with the help of dense behavioural datasets. Ultimately, the direction of sexual selection will be explored under the steering wheel of biased OSR in this promiscuous sexually coercive species. This story will synthesize various datasets (CR, experiments, dissections, hormones) amassed throughout the last decade of work on Golem Grad Island and try to envisage the fragile fate of this population, that may have already been sealed.

Last but not least, the potential conservation implications of such work will be discussed, placing an accent on these systems in the developing world.

Non-profitable long-term fundamental research is of no interest in these areas, thus conservation has drifted from a research-based necessity to merely goodon-paper results from pro-forma short-term activities. The system ends up satisfying detached international investors and local stakeholders with deep pockets, but does very little for nature conservation, if anything at all.

STUDY SYSTEMS & SETTING *

* Please find detailed statistical methodologies in the appendix.

STUDY SPECIES

The Hermann's tortoise (Testudo hermanni) is a medium sized terrestrial chelonian (130 -180mm average carapace length) inhabiting Europe's Mediterranean. It is comprised of two subspecies, T. h. hermanni to the west of Po Valley in NE Italy and T. h. boettgeri to the east covering a large part of the Balkan Peninsula [START_REF] Bertolero | Testudo hermanni (Gmelin 1789) -Hermann's Tortoise[END_REF].

Males are the smaller sex in the Hermann's tortoise (Djordjevic et al. 2011). This is only evident in mature individuals; immature tortoises cannot be sexed with certainty. Unlike closely related species (e.g. T. graeca), the Hermann's tortoise has a pronounced horny claw-like scale at the tip of the tail. It is more pronounced in males, and it is used to aggressively stimulate females during courtship. Hermann's tortoises practice sexual coercion; courtship entails chasing, head bobbing, biting, and mounting, during which, more often than not the female actively attempts to flee [START_REF] Hailey | Adult survival and recruitment and the explanation of an uneven sex ratio in a tortoise population[END_REF][START_REF] Sacchi | A Comparison among Sexual Signals in Courtship of European Tortoises[END_REF]. Mounting and copulation are often accompanied with high pitched male vocalization [START_REF] Galeotti | Olfactory Discrimination of Species, Sex, and Sexual Maturity by the Hermann's Tortoise Testudo hermanni[END_REF]). Maximum clutch size in females of the eastern subspecies is nine with an average of 4.3. Sex determination is temperature dependent [START_REF] Pieau | Temperature variation and sex determination in reptiles[END_REF]. Among populations, operational sex ratio (OSR) can be biased in favour of either sex [START_REF] Hailey | Adult survival and recruitment and the explanation of an uneven sex ratio in a tortoise population[END_REF][START_REF] Hailey | Population density and adult sex ratio of the tortoise Testudo hermanni in Greece: evidence for intrinsic population regulation[END_REF]. When present, the origin of OSR bias is not yet clear.

Mediterranean Testudo species accumulate growth rings on their shells that correspond to their periods of active thermoregulation intersected by prolonged hibernation events [START_REF] Lagarde | Sexual size dimorphism in steppe tortoises (Testudo horsfieldi): growth, maturity, and individual variation[END_REF]Bertolero et al. 2005).

Hermann's tortoises are indeterminate growers, with growth usually decelerating at maturity. Once this happens, growth rings become narrow and eventually blend into each other adding up to a smooth carapace in old individuals (+25 years). This offers a very convenient method of age estimation for immature and recently matured individuals. On average, before maturity Hermann's tortoises grow 10mm/year [START_REF] Willemsen | Variation in adult survival rate of the tortoise Testudo hermanni in Greece: implications for evolution of body size[END_REF]) and can become mature at various body sizes. Size at maturity is the proximate cause of variation in adult size [START_REF] Willemsen | Variation of adult body size of the tortoise Testudo hermanni in Greece: proximate and ultimate causes[END_REF]).

Hermann's tortoises occupy various habitats ranging from cultivated plains and open Mediterranean scrublands to closed forests [START_REF] Longepierre | Home range area in the tortoise Testudo hermanni in relation to habitat complexity: implications for conservation of biodiversity[END_REF]. Adults can travel up to 80m daily [START_REF] Hailey | How far do animals move? Routine movements in a tortoise[END_REF][START_REF] Rozylowicz | Habitat selection and movement ecology of eastern Hermann's tortoises in a rural Romanian landscape[END_REF][START_REF] Sibeaux | Sex-specific ecophysiological responses to environmental fluctuations of free-ranging Hermann's tortoises: implication for conservation[END_REF], and in doing so can encounter various hindrances depending on habitat (Golubović et al. 2013a(Golubović et al. , b, 2014)). Tortoises seem to experience habitat-specific locomotor challenges, ranging from dense shrubs slowing down progression, to steep, rocky areas promoting more frequent flipping of tortoises on their dorsum [START_REF] Golubović | Variations in righting behaviour across Hermann's tortoise populations: Righting behaviour in Hermann's tortoise[END_REF][START_REF] Golubović | Skills or strength-how tortoises cope with dense vegetation?[END_REF].

STUDY SITES

Two populations of eastern Hermann's tortoises were monitored for 10 and 8 years (from 2008 and 2010 until present day) on Golem Grad island (40°25'09"N, 20°59'17"E) and in Konjsko village (40°54'46"N, 20°59'17"E), respectively. Both localities are in the Prespa region of the Republic of Macedonia, situated in the far south-west of the country, bordering Albania and Greece (Fig. 1). They lay on the shores of Lake Prespa, separated from each other by a water barrier spanning ~4.5km. There are no constant human settlements in either locality; Konjsko is a popular vacation spot during the summer months when there is continuous human presence, whereas Golem Grad island does not hold accommodation and only short visits are allowed. Both localities are within the borders of National Park "Galićica", and Golem Grad additionally (on paper) enjoys the protection status of a nature reserve. The climate of the region is governed by its latitude, altitude (~850 m asl) and the buffering capacity of the lake; with both Mediterranean and continental influences it is formally defined as modified Mediterranean with mildly cold winters and hot summers [START_REF] Lazarevski | Klimata vo Makedonija[END_REF].

Konjsko is situated on a small peninsula on Prećna Mountain (part of Galićica Mountain, Fig. 1) covering an area of ~20ha. Its circumference is thus mostly outlined by beaches and a land connection to the west. On this side there is no physical barrier that could prevent the dispersal of tortoises; the population is thus semi open. Centrally Konjsko summits at a small hill (Blut) covered by an oak forest. For the most part, the stony beaches are covered by undergrowth of vines and shrubs. The habitats in Konjsko are physically generally uniform, lacking steep steps and obstacles.

Golem Grad island covers a surface area of ~18ha; terrestrial species here are locked (no immigration or emigration). Interestingly, the island is comprised of two broadly different habitats -stony beaches mostly covered in undergrowth, and a plateau covered in a coniferous forest of the Greek juniper (Juniperus excelsa). They are separated from each other by 10-30m high steep cliffs; two steep accession paths exist at the southern and north-western sides of the island. Golem Grad is characterized with uneven and rocky habitats adding up to a rugged topography.

Besides the Hermann's tortoise, the island is home to dense populations of three other reptile species: the wall lizard (Podarcis muralis), the dice snake (Natrix tessellatta), and the horn-nosed viper (Vipera ammodytes, next page).

The monitored tortoise populations are genetically hardly distinguishable (unpublished data). Nevertheless, risk taking behaviours seem to reflect habitat type and configuration, Golem Grad promoting willingness to jump from high obstacles unlike Konjsko tortoises (Golubović et al. 2013a). Tortoises were searched for visually. Before capture, in order to limit disturbance, location and behaviour (Table 6 in the appendix

RESULTS

The (192.5 vs. 171.5), the largest female (237.0mm) being 23mm longer than the largest male (214.0mm).

Age-specific variation in body size (VBS)

Visual exploration of the frequency distribution of individual SCLs for each of the first 9 years of life revealed two abrupt shifts in VBS separating three groups of juveniles: very young individuals measured during their first year of life (the first shift occurs between one and two years), young two-to four-yearold individuals (the second shift occurs between four and five years), and then individuals older than five years (p. 34, Fig. 7; see Table 1 for shifts in σ between age classes). This step pattern suggests that VBS increases with age in a nonregular step-wise way.

Population and cohort mean asymptotic sizes

The von Bertalanffy and logistic growth models fitted on the known age group yielded drastically different outcomes (p. 35, Table 9). Nevertheless, both models showed similar broad fitting (Bertalanffy R² = 7.5; Logistic R² = 7. In individuals of unknown age, the three-parameter von Bertalanffy growth equation yielded SCLA and SCL0 of 180.7 ± 0.9 and 34.6 mm, respectively.

These values were closer to the logistic model of the known age group compared to the output of the Bertalanffy model, suggesting that the growth patterns of juveniles and adults differ. Sex-specific analyses of the individuals of unknown age indicated that females should attain a larger size than males, both considering hatchling (SCL0) and asymptotic adult sizes: 38.7 mm versus 33.9 mm at hatching, and 188.7 ± 6.3 mm versus 179.9 ± 1.9 mm asymptotic SCL (p.

35, Table 9).

Individual variation in size and growth

Bootstrapping the original sample of individuals of known age and estimating asymptotic size of each bootstrap suggests that even though there is a clear population mean asymptotic size, there exist early-age, likely immature individuals (predominantly one-to-10-year-olds) with idiosyncratic trajectories.

Such individuals have driven the estimated SCLA values of 10,000 bootstraps to range from 162.8 ± 6.2 to 189.4 ± 6.4 mm.

The asymptotic sizes based on the 97 particularly well-monitored (consecutive annual recaptures ≥ 5) individuals ranged between 152.5 ± 6.3 and 212.4 ± 9.0 mm in males, and between 180.5 ± 4.0 and 223.8 ± 12.3 mm in females.

Although females exhibit the largest estimated asymptotic size, they were actually not consistently larger than males. In both sexes, asymptotic size varied greatly; the magnitude of variation was 59.9 mm in males, and 43. Finally, the individual-based growth trajectories showed that regardless of SCL at first capture, mature tortoises can still end up at different asymptotic size (p. 35, Fig. 9). The range of projected growth from capture to asymptotic size spanned between 0.0 and 40.3 mm.

BODY CONDITION

After model selection, variation in body condition index (BCI) was best explained by the interactive effect of sex and locality (Table 2). The variance explained by the random factor was 0.60, rendering it necessary to avoid pseudo-replication from measurements of recaptures. Konjsko tortoises exhibited higher BCIs in general (t = 30.57, p < 0.001), the males being worse off than the females (t = -21.69, p < 0.001). Boxplots of the predictions based on the best-fitted model clearly differentiate females from Konjsko as the most fit cohort regarding BCI (p. 36, Fig. 10). 3). 3.3.1.1. Golem Grad After model selection (Table 4) the best-fitted model implied different capture probabilities between years, sexes and heterogeneity classes.

On average high capture heterogeneity females had lower annual capture probability (0.56, CI 0.48-0.63) than their male counterparts (0.63, CI 0.60-0.66).

The same trend was evident among low capture heterogeneity individuals (females = 0.06[0.02-0.18], males = 0.41[0.32-0.50]). Recovering a male carapace from a dead individual (0.61[0.39-0.79]) was more likely than recovering one from a female (0.39[0.32-0.46]). Survival was strongly sex dependent, adult females expressing surprisingly low survival probabilities of 0.84 (CI 0.80-0.87).

Adult males, on the other hand express much higher mean annual survival of 0,97 (CI 0.96-0.98).

Konjsko

After model selection (Table 5) adult Konjsko tortoises expressed constant capture probabilities across sexes, without capture heterogeneity.

Probabilities to capture adult tortoises varied between years, likely due to field effort. Years of very low field effort (2012)(2013)(2014)(2015) yielded capture probabilities ranging between 0.03-0.05, whereas years of high field effort (2010, 2016 & 2017) resulted with higher probabilities of 0.36-0.44. The best-fitted model implied sex-specific survival. Nevertheless, DAIC between this model and the one suggesting constant survival among sexes was only 2.5 (Table 5) and according to the former there was no significant difference in adult survival estimates. Consequently, further discussion will be based on the model with less parameters (Table 5, highlighted row) demonstrating that annual adult survival among Konjsko tortoises is 0.93 (95% CI 0.90-0.95).

Survival temporal variance & canalization

The temporal variance of adult survival on Golem Grad island is clearly sexspecific, females experiencing significantly higher variation (mean=0.09) than males (mean=0.01, Fig. 4). Several bootstraps provided negative estimates of temporal variance for males. Gould & Nichols (1998) state that this is not uncommon in statistical literature and is most likely a result of very low temporal variance (zero or close); these instances were therefore regarded as zero values.

Population projections

Annual population growth rates (l) differed between scenarios, from highest without sex-specific survival (1.04), lower with sex-specificity (0.98), and lowest when Island Plateau-female-specific survival estimates were accounted for after the age of eight (0.97). With an initial population size of 2,000 individuals (an approximation of the current population size) and an even OSR at birth, OSR stayed even in the first case scenario and the population experienced constant growth, whereas for the latter two OSR reached present day values after ~40 and ~65 years (p. 37, Fig. 12), respectively, and after 100 years they both faced a fiveto nine-fold population drop (390 and 230 individuals, respectively).

SEXUAL BEHAVIOUR

Behavioural data in a CR framework

Between 2008 and 2014, 7,503 behavioural observations were collected on Golem Grad (Table 1 in the appendix [1A]). Adult females were more frequently inactive (i.e., partly sheltered and motionless) compared with adult males (χ2 = 30.6, P < 0.001, Table 1A). Many classical heterosexual behaviours (HSB) and male-to-male combats were observed, but most of the sexual behaviours recorded on this small island were same sex sexual behaviours (SSB) (Table 1A): For instance, on 295 occasions, a male was observed mounting another male (with vocalizations and/or ejaculation). SSB (i.e., mounting + courting and so on, Table 1) largely dominated among Plateau-males (74% SSB, N = 786), whereas HSB were more frequent among Shoreline-males (33% SSB, N = 102). SSB was exhibited by different individuals (N = 363) and thus was attributable to males at large (not only few individuals). 5a).

Transition probabilities between SSB versus HSB were sex and site dependent (Table 8, model 4). However, ∆QAIC between models 4, 6, and 8 were low. We selected model 4 (lowest absolute QAIC) for biological reasons (Burnham and Anderson 2002). Indeed, this model takes into account differential survival between sites, and this conforms, for example, to the fact that females face greater environmental difficulties on the plateau compared with the shoreline (e.g., water unavailability during summer). Furthermore, by selecting the second-best model ( 6), the transition probabilities between sexual behaviours were still site and sex dependent. Individual males were not strictly homosexual or heterosexual, shifting between SSB and HSB. However, the annual probabilities for a sexually inactive male in year t to engage in SSB in year t + 1 were significantly higher on the plateau than on the shoreline (Figure 5b).

The annual numbers of heterosexually active individuals versus individuals exhibiting SSB were estimated using raw numbers of individuals captured each year along with their capture probabilities from the bestsupported model (Table 8). Parametric bootstrapping was used to estimate confidence intervals. Each year on average, 97±27 adult tortoises display HSB versus 139±34 exhibiting SSB.

Sexual coercion (index of cloacal damage)

Mean body size differed significantly between populations, with females in Konjsko being larger (ANOVA with Box-Cox-transformed SCL as the dependent variable, F1, 206=154.41, p<0.001). Mean body size differed significantly among the five injury-level categories without interaction between populations; larger females experienced more severe injuries (Table 9). As for swollenness, body size did not differ among the seven categories (F6, 194=0.704, p=0.646), but the two populations were significantly different (F1, 194=47.38, p=0.001). In both populations, many large females (SCL>170 mm) exhibited severe cloacal injuries (p. 67, Figure 16). But on Golem Grad exclusively, smaller adult females (i.e. 150-170 mm SCL) were also severely injured. This was not the case for smaller adult Konjsko females that were spared from cloacal damage.

Remarkably, many small sub-adult females (130mm<SCL<150mm) along with several smaller clearly immature females (SCL<130 mm; below the lower body size threshold for maturity) showed clear cloacal injuries on Golem Grad.

Overall, the two populations exhibited strong divergences in the relationship between body size (hence maturity) and the prevalence of cloacal injuries.

LOCOMOTOR PERFORMANCE, HABITAT TYPE & SEXUAL COERCION

Steep cliffs, carapaces & swift escapes

In total, on Golem Grad we recovered 249 dead adults, 39 females and 210 males.

The proportion of dead females with obvious carapace cracks (i.e. fallen from the cliffs) were recovered more frequently than males (8 vs. 13; χ 2 = 6.98, p = 0.008).

Locomotor performance under sexual coercion

In the experimental enclosure when five males were placed with one female, without exception, the males immediately started chasing and harassing the female, sometimes pushing her off the edge of the opening. When alone in the enclosure Golem Grad females made the decision to exit significantly more often than Konjsko females (χ2 = 1.55, p = 0.039). On the other hand, when with five coercive males these differences disappeared (χ2 = 0.18, p = 0.671). Interestingly, Konjsko females never jumped but were rather always pushed out by coercive males (Table S4). Regardless of scenario, Golem Grad females always approached the edge of the enclosure more often than those from Konjsko (alone: χ2 = 8.93, p = 0.003; with five males: χ2 = 41.33, p<0.001).

PHYSIOLOGICAL FRAMEWORK

Sexual behaviours

Testosterone levels (T) were compared using generalized linear models (GLM) with sex and population (male/female and Golem Grad/Konjsko, respectively) as explanatory variables and T level as the response variable. Mean T levels differed between sexes (Wald test = 215.82, P < 0.001) and between mainland and island populations (Wald test = 24.81, P < 0.001). Females displayed markedly lower T levels compared with males; the difference between the localities appeared weak (Fig. 6). However, removing the sex effect from the model decreased AIC (DAIC = 21), suggesting a significant population effect caused by the males: T levels were slightly albeit significantly lower on Golem Grad (4.6 ± 3.5 [SD] ng/ml), compared with Konjsko males (6.9±3.3ng/ml; Tukey post hoc test P < 0.01); no difference was observed in females (P = 0.916).

Subsequent effort focused only on males, since SA behaviours (e.g., courting, mounting, fighting), and high T levels were exclusively expressed by them. Five types of behaviours were distinguished: males found alone, mounted by another male, mounting another male, mounting a female, or during male-tomale combats (Fig. 6). A GLM revealed a significant effect of behaviour types on T levels (Wald test = 38.41, P < 0.001) and a significant difference between mainland and island populations (Wald test = 16.87, P < 0.001; as above AIC was lower in the full model, DAIC = 13.7). Further analyses (comparing all parameters estimated or using post hoc tests) suggested that sexually passive (SP) males (found alone or mounted) exhibited lower T levels compared with males involved in the most vigorous sexual behaviours (combat) whereas other active males (mounting) displayed intermediate T levels (Fig. 6). Because SSB was observed exclusively in Golem Grad males, we restricted some analyses to these individuals: Results were unchanged (GLM analysis revealed a strong effect of behaviour type, Wald test = 37.37, P < 0.001). Thus, we observed a trend of higher T levels in those males sampled during most demanding sexual behaviours, without an influence of SSB. Furthermore, the significant effect of mainland/island populations and examination of Figure 6 suggest that this trend was specific to Golem Grad.

Sample sizes were small in males from the continent and in fighting island males, shedding uncertainty on some of the results above. Therefore, to examine the main effect (i.e., higher T level in the most active males) with sufficient statistical power, we used broad behavioural categories: SA (N = 46) versus sexually inactive males (N = 157). Mean T levels differed between these groups (GLM, Wald test = 19.86, P < 0.001) with a mainland/island effect (GLM, Wald test = 20.77, P < 0.001). Overall, our results suggest a relationship between T level and sexual activity in males without specific effect of SSB.

Male maturity

The onset of reproductive maturity should follow a spike in T levels due to the activation of endocrinological pathways [START_REF] Nelson | An introduction to behavioral endocrinology[END_REF]). The dashed line in Figure 13 (p. 37) indicates that males reach maturity on Golem Grad at a minimal size of 115mm SCL. Females never show an increase in T levels. T levels thus seem to be a good indicator of maturity in males and can be used as a tool to sex sexambiguous males that have already reached maturity given they exhibit high T levels at the time of sampling. 3.

BEHAVIOUR AT BLOOD SAMPLING A L O N E P A S S IV E S S B A C T IV E S S B H E T E R O M A T IN G C O M B A T F E M A L E A L O N E H E T E R O M A T IN G F E M

WHEN CARAPACE GOVERNS SIZE: VARIATION AMONG AGE CLASSES AND INDIVIDUALS IN A FREE-RANGING ECTOTHERM WITH DELAYED

MATURITY [2018, Oecologia 186: 953-963, Arsovski D, Tomović Lj, Golubović A, Nikolić S, Sterijovski B, Ballouard J-M, Bonnet X] Growth rate during early life is a major determinant of adult body size, especially in species with delayed maturity [START_REF] Stearns | The Evolution of Life Histories (1 edition)[END_REF][START_REF] Madsen | Silver Spoons and Snake Body Sizes: Prey Availability Early in Life Influences Long-Term Growth Rates of Free-Ranging Pythons[END_REF]; body size, in turn, has ubiquitous impacts on life history traits [START_REF] Peters | The ecological implications of body size[END_REF]. Selective forces that control variation in body size (VBS) over time are omnipresent. VBS at birth (static heterogeneity) can either be countered by compensatory effects of growth, or fuelled by the cumulative effects of the environment and create "dynamic heterogeneity" [START_REF] Tuljapurkar | Dynamic heterogeneity in life histories[END_REF]). The constant face-off between these effects can generate cohort VBS, and theory suggests that longer generation times should correlate with lower initial VBS and a faster decline throughout life and vice versa [START_REF] Gaillard | Temporal variation in survival of mammals: A case of environmental canalization?[END_REF]; ungulates neatly follow this rule (Hamel et al. 2016). Consequently, in the pursuit to better understand growth variation and VBS, accurate descriptions of (individual/cohort) growth curve shapes are necessary, and prolonged immaturity mandates that they rely on large datasets that include long-term monitoring of individuals across all age classes. Alas, immature individuals tend to escape observation [START_REF] Paradis | Estimation of Sex-and Age-Related Survival Rates in a Microtine Population[END_REF][START_REF] Pike | Estimating survival rates of uncatchable animals: the myth of high juvenile mortality in reptiles[END_REF], precluding detailed descriptions of (individual) juvenile growth curves. In long-lived species with delayed maturity, complex, species-specific juvenile growth curves have only been obtained from humans, few mammal species in captivity [START_REF] Setchell | Growth and ontogeny of sexual size dimorphism in the mandrill (Mandrillus sphinx)[END_REF], and sea turtles [START_REF] Chaloupka | A polyphasic growth function for the endangered Kemp's ridley sea turtle, Lepidochelys kempii[END_REF][START_REF] Chaloupka | Polyphasic Growth in Pelagic Loggerhead Sea Turtles[END_REF]). In humans, although growth is not yet fully characterized [START_REF] Gliozzi | A novel approach to the analysis of human growth[END_REF], there are two periods of accelerated growth that occur, respectively, after birth and several years later during adolescence [START_REF] Davenport | Human Growth Curve[END_REF][START_REF] Leigh | Evolution of human growth spurts[END_REF]. A very different pattern was observed in laboratory rats where growth rate progressively rises after birth and then exhibits a gradual decline prior to maturity [START_REF] Hughes | A longitudinal study of the growth of the blackhooded rat: methods of measurement and rates of growth for skull, limbs, pelvis, nose-rump and tail lengths[END_REF]. Sea turtles display two growth spurts taking place just after birth and then a few years later. This is the only example from free-ranging animals, yet it is based on relatively small and sparse samples and indirect skeletochronological ageing techniques, and should thus be considered with care [START_REF] Chaloupka | A polyphasic growth function for the endangered Kemp's ridley sea turtle, Lepidochelys kempii[END_REF][START_REF] Chaloupka | Polyphasic Growth in Pelagic Loggerhead Sea Turtles[END_REF]. Nonetheless, differences in growth curve shapes, driven by variation of critical period(s), may well be species specific, and should be scrutinized. Thus far, mark-recapture studies performed on free-ranging individuals belonging to different taxa have provided extremely valuable information [START_REF] Dietz | Seasonal variation in reproduction, juvenile growth, and adult body mass in golden lion tamarins (Leontopithecus rosalia)[END_REF]Lenihan & Van Vuren 1996). However, in most cases the juvenile sample size was limited to few observations and precise analyses were hampered by long intervals between recaptures before maturity; only crude juvenile growth patterns were inferred. The paucity of data explains why usually a linear, or a simple asymptotic growth curve was extracted [START_REF] Congdon | Growth and body size in Blanding's turtles (Emydoidea blandingi): relationships to reproduction[END_REF][START_REF] Dietz | Seasonal variation in reproduction, juvenile growth, and adult body mass in golden lion tamarins (Leontopithecus rosalia)[END_REF]Lenihan & Van Vuren 1996;[START_REF] Zug | Age and growth in Leatherback Turtles, Dermochelys coriacea (Testudines: Dermochelydae): A Skeletochronological Analysis[END_REF][START_REF] Beaupre | Ontogenetic Variation in Growth and Sexual Size Dimorphism in a Central Arizona Population of the Western Diamondback Rattlesnake (Crotalus atrox)[END_REF][START_REF] Dodd | Habitat disturbances differentially affect individual growth rates in a long-lived turtle[END_REF][START_REF] Scott | Life in the really slow lane: loggerhead sea turtles mature late relative to other reptiles: Reptile age at maturity[END_REF]Rodriǵuez-Caro et al. 2013) and rapid ontogenic changes in growth velocity may have been missed. To our knowledge growth spurts have been directly identified from dense and continuous repeated records only in humans, captive primates and in industrially raised animals, only when the time elapsed between successive measurements was reduced [START_REF] Jobling | The compensatory growth response of the Atlantic cod: effects of nutritional history[END_REF][START_REF] Noy | Posthatch Development in Poultry[END_REF]. Perhaps other taxa display effectively simpler growth patterns? -It would be remarkable to observe that the kinetic of growth exhibits complex patterns only in those species where juveniles have been intensively monitored through regular recaptures of known individuals.

Several reptile species combine delayed maturity, long life expectancy, and wide ranges of body sizes [START_REF] Andrews | Patterns of Growth in Reptiles[END_REF][START_REF] Stearns | The Effects of Size and Phylogeny on Patterns of Covariation in the Life History Traits of Lizards and Snakes[END_REF][START_REF] Dunham | Patterns of Covariation in Life History Traits of Squamate Reptiles: The Effects of Size and Phylogeny Reconsidered[END_REF][START_REF] Berrigan | Reaction Norms for Age and Size at Maturity in Response to Temperature: A Puzzle for Life Historians[END_REF]. In these organisms, adult body size responds to environmental factors with cascading effects on most life history traits [START_REF] Madsen | Silver Spoons and Snake Body Sizes: Prey Availability Early in Life Influences Long-Term Growth Rates of Free-Ranging Pythons[END_REF][START_REF] Niewiarowski | Reciprocal Transplant Reveals Sources of Variation in Growth Rates of the Lizard Sceloporus Undulatus[END_REF][START_REF] Caley | Complex growth rate evolution in a latitudinally widespread species[END_REF].

Chelonians provide excellent examples of extremely delayed maturity that leaves plenty of room for complex growth trajectories to establish idiosyncratic routes during a prolonged and substantial increase in size. Immediately after hatching, individuals are naïve and must find appropriate resources. Exploring novel environments can defer growth. Indeed, small tortoises are extremely vulnerable and they must intensively use shelters, trading foraging for safety (Ballouard et al. 2013). Over time, the protective value of the shell increases and larger, more progressive increase in VBS is surprising for an animal so low on the slow-fast continuum. Long-lived animals invest in survival rather than reproduction [START_REF] Gaillard | Temporal variation in survival of mammals: A case of environmental canalization?[END_REF], so smaller more vulnerable individuals are under pressure to grow and catch up with their mates, thus continuously decreasing VBS. However, considering the delayed costs of compensatory growth (Metcalfe & Monagan 2001), a chelonian's hardened carapace may well compensate for the survival benefits size would otherwise bring at an earlier age. In other words, the survival benefits of a hardened carapaces may give young and small (relative to their age) tortoises the option of deterring possibly costly compensatory growth, thus promoting an increase in age-specific VBS. A marked increase in these tortoises' survival between the third and fifth year of age (p. 36, Fig. 11) remarkably corroborates this idea. Determinate growers, such as ungulates, pay the price in order to reach a safe size before growth ceases, therefore they experience an ever-decreasing VBS (Hamel et al. 2016). On the other hand, the Hermann's tortoise can grow significantly after maturity (p. 35, Fig. 9); accompanied by a solid carapace at the age of five this seems to translate into liberty in growth regimes regardless of maturity. In sea turtles, indirect skeletochronological ageing techniques suggested similar polyphasic growth before maturity, supposedly driven by diet shifts and changes in foraging areas [START_REF] Chaloupka | A polyphasic growth function for the endangered Kemp's ridley sea turtle, Lepidochelys kempii[END_REF][START_REF] Chaloupka | Polyphasic Growth in Pelagic Loggerhead Sea Turtles[END_REF]). These results based on CMR data provide strong support to these pioneer studies and thus to the fact that complex patterns in chelonian growth before maturity might be more widespread than currently assumed. Aggregating immature individuals and thus neglecting possible rapid non-linear developmental shifts may result with major imprecision when studying the fitness consequences of early life variations. The elusive nature of immature individuals should promote a more systematic approach; for example, in reptiles artificial shelters and/or specific searching sessions bolster the detection of otherwise uncatchable juveniles [START_REF] Bonnet | The dangers of leaving home: dispersal and mortality in snakes[END_REF][START_REF] Bonnet | Coastal Nurseries and Their Importance for Conservation of Sea Kraits[END_REF][START_REF] Ballouard | Fibrocement slabs as useful tools to monitor juvenile reptiles: a study in a tortoise species[END_REF]. Precisely on Golem Grad most very small tortoises were found sheltered under stones while larger individuals were found using the classical visual searching technique.

Between the ages of nine-20 years, annual growth rate decreases markedly (p. 34, Fig. 8) and becomes negligible as observed in other populations [START_REF] Bertolero | Testudo hermanni (Gmelin 1789) -Hermann's Tortoise[END_REF]. Supposedly this sharp decrease leaves little room for subsequent growth to contribute to individual variation in maximal body size. [START_REF] Willemsen | Variation of adult body size of the tortoise Testudo hermanni in Greece: proximate and ultimate causes[END_REF] argued that the duration of growth before it decelerates is the only proximate cause of variation in adult size. The SCL range (155.5-218.2 mm) of the oldest individuals (characterized by smooth shells, presumably more than 25 years old; close to asymptotic size) should thus be projections of the spectrum of tortoise sizes at their respective times when growth had decelerated. However, not all adults in our population seem to fully conform to this scenario. Figure 9 (p. 35) demonstrates that adult tortoises display a wide range of growth trajectories relatively independently from their body size at first capture. In other words, despite a reduced growth rate, substantial individual variations can be measured in adult tortoises, providing that large sample sizes are continuously monitored on the long-term (e.g. 5-10 years). Overall, the duration of growth before it decelerates is a crucial proximal cause of variation in size; however later interactions between genes and the environment during the long mature life of tortoises may well significantly influence asymptotic size.

Further disentangling the respective contributions of various growth rates before and after maturity on individual size is not easy, but it might be crucial to better understand the actual extensive range of body sizes found in many longlived ectothermic species [START_REF] Gotthard | Growth strategies of ectothermic animals in temperate environments[END_REF]. This is an important issue because body size influences many life history traits: for example, mating success during ritual fights in males [START_REF] Willemsen | Variation of adult body size of the tortoise Testudo hermanni in Greece: proximate and ultimate causes[END_REF] or fecundity in females [START_REF] Andersson | Sexual selection[END_REF], Lagarde et al. 2001). On the other hand, selective advantages of smaller size may maintain variation: early maturing small individuals may invest more resources into reproduction rather than growth, thereby balancing the advantage of a large body size [START_REF] Stearns | The Evolution of Phenotypic Plasticity in Life-History Traits: Predictions of Reaction Norms for Age and Size at Maturity[END_REF]. Additionally, variations in foraging resources may influence the opportunity for individuals to express their own growing potential [START_REF] Gotthard | Growth strategies of ectothermic animals in temperate environments[END_REF].

Finally, there is no dearth in reptile growth studies, and for a big part our data conforms to existing knowledge. Nevertheless, it has become evident that major gaps still exist, particularly when studying the long immature phase of reptiles with delayed maturity. The complexities that have been pin pointed in this study surely penetrate even deeper into the specific life history characteristics of this phase. Possible consequences on variation in adult traits urge further exploration of interactions between environmental fluctuations and age-cohort peculiarities.

COVARIATES STREAMLINE AGE-SPECIFIC EARLY LIFE SURVIVAL ESTIMATES OF TWO CHELONIAN SPECIES [2018, J Zool In press, Arsovski D, Olivier A, Bonnet X, Drilholle S, Tomović Lj, Béchet A, Golubović A, Besnard

A]

This paper deals with the age-survival relationship prior to maturity (or at its Nevertheless, developmental changes throughout a prolonged immature phase can induce huge variation in trait values; e.g. before (delayed) maturity mean annual survival increases linearly with age (see for instance [START_REF] Congdon | Demographics of Common Snapping Turtles (Chelydra serpentina): Implications for Conservation and Management of Long-Lived Organisms[END_REF][START_REF] Jorgenson | Effects of Age, Sex, Disease, and Density on Survival of Bighorn Sheep[END_REF][START_REF] Fernández-Chacón | Spatial heterogeneity in the effects of climate change on the population dynamics of a Mediterranean tortoise[END_REF][START_REF] Hastings | Cohort effects and spatial variation in age-specific survival of Steller sea lions from southeastern Alaska[END_REF][START_REF] Delong | Age-and sex-specific survival of California sea lions (Zalophus californianus) at San Miguel Island, California[END_REF]. This complicates the understanding of trait covariation and mandates age-, or at least stage-specific estimates. European pond turtles (for details on field methodology see [START_REF] Olivier | Assessing spatial and temporal population dynamics of cryptic species: an example with the European pond turtle[END_REF]Ficheux et al. 2015). Among these, 298 could be aged using growth-rings [START_REF] Castanet | Les méthodes d'estimation de l'âge chez les chéloniens[END_REF][START_REF] Olivier | Ecologie, traits d'histoire de vie et conservation d'une population de cistude d'Europe Emys orbicularis en Camargue (Master)[END_REF] for a total of 809 captures.

Sex was assigned for sexually-dimorphic individuals followed by permanent notch marking on the carapace (Cagle F.R. 1939).

Longevity and delayed maturity are often expressed to the extreme in chelonians [START_REF] Wilbur | Life-history evolution in turtles[END_REF]. At present day, an ever-increasing set of threats [START_REF] Klemens | Turtle conservation[END_REF] 11). Much is likely a consequence of inherent interspecific differences; in juvenile tortoises survival estimates range from eight to 90%, whereas in juvenile sea turtles they almost always exceed 70% (Table 11).

Perhaps even more importantly, the plethora of methodological approaches (last column, Table 11) likely contributes largely to this variation (see also [START_REF] Pfaller | Phylogeny, biogeography and methodology: a meta-analytic perspective on heterogeneity in adult marine turtle survival rates[END_REF]). [START_REF] Jorgenson | Effects of Age, Sex, Disease, and Density on Survival of Bighorn Sheep[END_REF][START_REF] Schwarz | Estimation of juvenile survival, adult survival, and age-specific pupping probabilities for the female grey seal (Halichoerus gryprus) on Sable Island from capture-recapture data[END_REF][START_REF] Shine | Patterns of Survival, Growth, and Maturation in Snakes and Lizards[END_REF]. Different species reach their respective survival plateaus at different ages, often corresponding with maturity (2-3 years in bighorn sheep [START_REF] Jorgenson | Effects of Age, Sex, Disease, and Density on Survival of Bighorn Sheep[END_REF] note that first reproduction usually occurs later], 4 years in grey seals [START_REF] Schwarz | Estimation of juvenile survival, adult survival, and age-specific pupping probabilities for the female grey seal (Halichoerus gryprus) on Sable Island from capture-recapture data[END_REF], 7 years in Steller sea lions [START_REF] Hastings | Cohort effects and spatial variation in age-specific survival of Steller sea lions from southeastern Alaska[END_REF], five years in California sea lions [START_REF] Delong | Age-and sex-specific survival of California sea lions (Zalophus californianus) at San Miguel Island, California[END_REF]). Both Hermann's tortoises and European pond turtles reach maturity between the ages of eight and 12 (six in [START_REF] Olivier | Ecologie, traits d'histoire de vie et conservation d'une population de cistude d'Europe Emys orbicularis en Camargue (Master)[END_REF][START_REF] Rogner | European pond turtle Emys orbicularis[END_REF][START_REF] Bertolero | Testudo hermanni (Gmelin 1789) -Hermann's Tortoise[END_REF]), yet arrive at a survival plateau earlier at approximately four to five-years-old (p. 36,Fig. 11;Fig. 14). This is likely a consequence of the final hardening of the carapace, which can bring obvious survival benefits prior maturity [START_REF] Wilbur | Life-history evolution in turtles[END_REF]. After maturity, European pond turtles from Camargue experience sex differences in survival [START_REF] Olivier | Assessing spatial and temporal population dynamics of cryptic species: an example with the European pond turtle[END_REF]; nonetheless, our results overrule the possibility of it originating prior maturity. When immature neither species is obviously sexually dimorphic [START_REF] Bertolero | Testudo hermanni (Gmelin 1789) -Hermann's Tortoise[END_REF][START_REF] Rogner | European pond turtle Emys orbicularis[END_REF], thus sex-specific habits or environmental pressures (e.g. sexual coercion in the Hermann's tortoise [START_REF] Willemsen | Variation of adult body size of the tortoise Testudo hermanni in Greece: proximate and ultimate causes[END_REF]) that could influence survival prior maturity are either elusive, or likely not present. In adult Hermann's tortoises sex-specific survival is not common apart from few populations with a bias in sex-ratio [START_REF] Hailey | Population density and adult sex ratio of the tortoise Testudo hermanni in Greece: evidence for intrinsic population regulation[END_REF]. Interestingly, the Golem Grad tortoise population has the highest reported bias in sex-ratio of this species, reaching its maximum on the Plateau where only 5% of all adult individuals are female. Our best-fit model implies significantly lower survival of younger females from this locality from birth (p. 36, Fig. 11). We hypothesize this result to be a consequence of male coercion on the oldest females in our dataset, later projected onto the youngest age classes by the covariate. As such, this example is also a cautionary message on the use of covariates! This issue will be discussed at length in the following chapters.

The high variation in juvenile survival estimates that fail to give age or at least stage-specific estimates in Table 11 is likely owed to the age-class that was predominant in the respective datasets. This mandates prudence when interpreting them in an evolutionary-ecological framework or applying them to conservation policies. Our results corroborate that immature survival increases with age in long-lived species, additionally suggesting it occurs rather steeply in chelonians. This is likely a consequence of ontogenic shifts in morphology, physiology and behaviour and therefore alterations in interactions with the environment [START_REF] Golubović | Ontogenetic shift of antipredator behaviour in Hermann's tortoises[END_REF]. It would come as a surprise if shifts in agespecific survival do not translate to age-specific shifts in other aspect of a species' life-history. Indeed, after the age of five Golem Grad tortoises experience everincreasing age-specific body size variation (p. 34, Fig. 7). Armed with a hard carapace they can reach a survival plateau and therefore enough confidence to start expressing individuality in their respective environments; interestingly, our models' preference to consider tortoise capture probabilities independently per age after the age of five corroborates this notion. Remarkably, behavioural shifts might follow this trend as well: Hermann's tortoises alter their antipredator behaviours after maturity [START_REF] Golubović | Ontogenetic shift of antipredator behaviour in Hermann's tortoises[END_REF].

APPROACHING TORTOISE MATURITY: A STORY OF MALE PHYSIOLOGY

Testosterone is a sex steroid that mediates sperm production, the expression of secondary sexual characters, and the functions that naturally follow -courtship and sexual behaviours (Nelson R.J. 2005). Pleiotropies (multiple targets) and complex regulations (trade-offs) often characterize hormones, and testosterone is no exception, decreasing immune functions and parental care in some species for instance [START_REF] Ketterson | Adaptation, Exaptation, and Constraint: A Hormonal Perspective[END_REF][START_REF] Folstad | Parasites, Bright Males, and the Immunocompetence Handicap[END_REF][START_REF] Owen-Ashley | Androgens and the immunocompetence handicap hypothesis: unraveling direct and indirect pathways of immunosuppression in song sparrows[END_REF]). Thus, testosterone likely underlies important life-history trade-offs [START_REF] Zera | The Physiology of Life History Trade-Offs in Animals[END_REF], making it a useful indicator of important sexual traits such as maturity in males.

Consequently, and remarkably, age-specific testosterone levels tell a story similar to the ones told by sexual behaviours. The smallest sexually active male (seen mounting another tortoise) on the island was 123.00 mm long (SCL) and Figure 13 (p. 37) suggests that testosterone levels start increasing at the very approach of 120mm SCL.

FIRST REFLECTION -ON THE LIFE-HISTORY OF GOLEM GRAD HERMANN'S TORTOISES -

If I were to take previously discussed Golem Grad population-mean life-history estimates and write a short story extrapolating drawn conclusions into a specieswide reflection, the product would read: "Hermann's tortoises are armoured reptiles that hatch at a very small size (~30 -40mm SCL, Male tortoises only reach maturity later at the size of ³120mm SCL (Fig. 8, p. 34), after at least few years of already living as a self-sufficient individual.

Females supposedly reach this point at a larger size and presumably later [START_REF] Bertolero | Testudo hermanni (Gmelin 1789) -Hermann's Tortoise[END_REF]). Hermann's tortoises do not seem to be in a rush to spend their resources on reproduction -perhaps a freedom that only comes with a very long life, or perhaps indeterminate growth. Since VBS is very high at this point, 120mm SCL should only be regarded as the minimal size-at-maturity, but largest reported Hermann's tortoise was 346mm long [START_REF] Beshkov | Record-sized tortoises Testudo graeca obera and Testudo hermanni boettgeri from Bulgaria[END_REF])."

FROM RUN-OF-THE-MILL TO OUT-OF-THE-WAY: ISLANDS AS VECTORS OF PECULIARITIES AND MEDIATORS OF APPLIED RESEARCH

The beauty of the amassment of ecological [2016, Behav Ecol 27: 1206-1215, Bonnet X, Golubović A, Arsovski D, Djordjević S, Ballouard J-M, Sterijovski B, Ajtić R, Barbraud X, Tomović Lj] Due to their paradoxical consequences on reproduction, same-sex sexual behaviours (SSB) and their frequent occurrence in free-ranging animal species 2015) and induced disorders (e.g., using knockout mice; [START_REF] Bakker | Sexual partner preference requires a functional aromatase (cyp19) gene in male mice[END_REF][START_REF] Bakker | Alpha-fetoprotein protects the developing female mouse brain from masculinization and defeminization by estrogens[END_REF] with deleterious repercussions such as hyper aggressiveness or behavioural asexuality, creating artificial behaviours unlikely to be favoured by sexual selection [START_REF] Balthazart | Aromatase inhibition blocks the activation and sexual differentiation of appetitive male sexual behavior in Japanese quail[END_REF]). Nevertheless, empirical results suggest that male vertebrates that engage in SSB do not exhibit behavioural anomalies, are able to discriminate between the sexes, reproduce normally, and do not display unusual circulating testosterone levels (T) [START_REF] Poiani | Animal homosexuality: a biosocial perspective[END_REF], thus insight from such experimental studies will likely be difficult to translate onto natural systems.

♂ ♂

A PRISON EFFECT IN A WILD POPULATION: A SCARCITY OF FEMALES INDUCES HOMOSEXUAL BEHAVIOURS IN MALES

(
In captive animals, genetic, anatomical, neurophysiological, or hormonal investigations have failed to identify clear distinctions between the mechanisms that promote SSB versus HSB [START_REF] Poiani | Animal homosexuality: a biosocial perspective[END_REF][START_REF] Hoskins | A test of genetic models for the evolutionary maintenance of same-sex sexual behaviour[END_REF]. Even in humans, one of the most intensively studied vertebrate species, the abundant efforts to link sexual orientation with anatomy, physiology, and genetic mechanisms have revealed complex and equivocal patterns [START_REF] Banks | Hormones and sexual orientation: a questionable link[END_REF][START_REF] Rice | Male homosexuality: absence of linkage to microsatellite markers at Xq28[END_REF][START_REF] Zitzmann | Testosterone levels in healthy men and the relation to behavioural and physical characteristics: facts and constructs[END_REF][START_REF] Mustanski | A critical review of recent biological research on human sexual orientation[END_REF][START_REF] Jannini | Male homosexuality: nature or culture?[END_REF].

Although recent epidemiologic studies revealed that genetic factors influence human sexuality [START_REF] Jannini | Genetics of Human Sexual Behavior: Where We Are, Where We Are Going[END_REF], underlying genetic and physiological mechanisms of sexual orientation are not yet understood such that adaptive hypotheses remain controversial [START_REF] Rahman | The neurodevelopment of human sexual orientation[END_REF]. In free-ranging male Hermann's tortoises, high population densities combined with strongly male-biased SRs possibly generated a "prison effect" [START_REF] Bailey | Same-sex sexual behavior and evolution[END_REF] and SSB became more common than HSB in this situation only (Table 12). Hormonal investigations suggested that, not unlike other sexual behaviours, high expression of SSB correlated with high T levels. Remaining within the range of natural variations of T levels implies that SSB does not require specific adaptive or pathological explanations. In both the mainland and island populations, T levels were high in adult SA males, in accordance with the paradigm that androgenic steroids (e.g., T, 11-keto testosterone in fish) are primary stimulators of sexual activity in male vertebrates. Moreover, the most SA males (i.e., mating with females, engaged in SSB or combats, Figure 15) exhibited higher T levels, as observed in other reptiles [START_REF] Aubret | Fat is sexy for females but not males: the influence of body reserves on reproduction in snakes (Vipera aspis)[END_REF][START_REF] King | Seasonal, Condition-Dependent, and Individual Variation in Testosterone in a Natricine Snake[END_REF]. Because an individual is not continuously SA, some of the "inactive" individuals monitored during random-focal blood sampling undoubtedly were SA animals that we observed between bouts of reproductive behaviour (especially in mainland tortoises where lower density decreases encounter rate). Nonetheless, we recorded higher T in males displaying the most vigorous behaviours: fighting or mounting other males. Therefore, this suggests that the combination of high density and skewed SR led to frequent SSB in males, notably in individuals strongly stimulated by high T levels. External sexual stimuli (e.g., visual/chemical signals from conspecifics) can activate the brain structures involved in sexual arousal in adults [START_REF] Arnow | Brain activation and sexual arousal in healthy, heterosexual males[END_REF], high density promotes courtship behaviours in male tortoises [START_REF] Hailey | Population density and adult sex ratio of the tortoise Testudo hermanni in Greece: evidence for intrinsic population regulation[END_REF], and T level correlates with sexual reactiveness [START_REF] Amstislavskaya | Female-induced sexual arousal in male mice and rats: behavioral and testosterone response[END_REF][START_REF] Goldey | Sexual Modulation of Testosterone: Insights for Humans from Across Species[END_REF]. On Golem Grad, these factors were strongly amplified in males. Under strong sexual stimulation caused my multiple factors (high density + scarcity of females + high T levels), males attempted to copulate with the first encountered "partner," generally females on the shoreline but more often with males on the plateau. A relatively similar behavioural "libido syndrome" where the occurrence of heterosexual courtships positively correlates with SSB has been described in captive cockroaches [START_REF] Logue | A behavioral syndrome linking courtship behavior toward males and females predicts reproductive success from a single mating in the hissing cockroach, Gromphadorhina portentosa[END_REF].

Golem

Interestingly, libido scores also correlated with mating success, suggesting that selection for high heterosexual courtship intensity entailed nonadaptive SSB [START_REF] Logue | A behavioral syndrome linking courtship behavior toward males and females predicts reproductive success from a single mating in the hissing cockroach, Gromphadorhina portentosa[END_REF].

The studied population presents several exceptional characteristics and thus suffers from a lack of replication. Experiments where density and SR are manipulated are needed to gauge the validity of our conclusions. However, our results are based on a large sample size and long-term monitoring. Furthermore, the quasi-experimental shoreline/plateau situation of Golem Grad, along with the comparison with other populations belonging to different species (Table 12), offers support to the nonadaptive "prison effect" hypothesis [START_REF] Bailey | Same-sex sexual behavior and evolution[END_REF]. Plateau-males and to a lesser extent shoreline-males can rarely find adult females, but instead encounter many male tortoises that morphologically resemble females while they are under T stimulation. Hyperstimulation and/or frustration created by a similar situation may promote frequent SSB as documented in feral-domestic cats [START_REF] Yamane | Frustrated felines: male-male mounting in feral cats[END_REF]. Deprivation of member(s) of the opposite sex generates sexual strain that can be relaxed by different behavioural outlets including onanism, SSB, or interspecific sexual behaviours [START_REF] Exton | Endocrine response to masturbation-induced orgasm in healthy men following a 3-week sexual abstinence[END_REF][START_REF] Yamane | Frustrated felines: male-male mounting in feral cats[END_REF][START_REF] Sakaguchi | The lower salivary testosterone levels among unmarried and married sexually active men[END_REF]. A positive impact of abstinence (a proxy of frustration) on both T levels and sexual motivation has been documented in humans [START_REF] Exton | Endocrine response to masturbation-induced orgasm in healthy men following a 3-week sexual abstinence[END_REF][START_REF] Sakaguchi | The lower salivary testosterone levels among unmarried and married sexually active men[END_REF]). Yet, nonadaptive SSB may simply reflect behavioural mistakes, such as inaccurate sexual partner discrimination [START_REF] Scharf | Same-sex sexual behavior in insects and arachnids: prevalence, causes, and consequences[END_REF]. Although these explanations are not exclusive, the hypothesis that males cannot discriminate sex has been rejected experimentally [START_REF] Galeotti | Olfactory Discrimination of Species, Sex, and Sexual Maturity by the Hermann's Tortoise Testudo hermanni[END_REF]). Many studies demonstrated the strong ability of tortoises, and of nonavian reptiles in general, to use chemical cues to distinguish sexual partner (Cooper and Perez-Mellado 2002;[START_REF] Shine | Cryptic forcible insemination: male snakes exploit female physiology, anatomy, and behavior to obtain coercive matings[END_REF][START_REF] Poschadel | Response to Chemical Cues from Conspecifics Reflects Male Mating Preference for Large Females and Avoidance of Large Competitors in the European Pond Turtle, Emys orbicularis[END_REF]Ibańẽz et al. 2012). Overall, SSB may emerge and persist in natural populations because the costs for total SSB inhibition outweigh the costs of nonadaptive SSB [START_REF] Thornhill | Homosexual behaviour in animals: an evolutionary perspective[END_REF][START_REF] Burgevin | Intersexual correlation for samesex sexual behaviour in an insect[END_REF][START_REF] Scharf | Same-sex sexual behavior in insects and arachnids: prevalence, causes, and consequences[END_REF][START_REF] Engel | Acceptance threshold theory can explain occurrence of homosexual behaviour[END_REF]. Mechanisms that eliminate SSB may negatively impact on HSB, for example, through a decrease of general sexual motivation if common neuroendocrine pathways are involved.

Precisely, in vertebrates, T stimulates hypothalamic areas that promote both heterosexual and homosexual activity [START_REF] Bakker | Sexual partner preference requires a functional aromatase (cyp19) gene in male mice[END_REF][START_REF] Bakker | Alpha-fetoprotein protects the developing female mouse brain from masculinization and defeminization by estrogens[END_REF]. We speculate that the development, maintenance, and functioning of specific neuroendocrine structures that selectively filter out SSB might be too expensive (and useless) in male tortoises. Other unusual sexual behaviours observed on Golem Grad Island, especially on the plateau, reinforce the notion that the most SA adult males deprived of females were highly stimulated (Fig. 15). Males (N = 12) were observed mounting juveniles, dead males, and tortoise skeletons (empty shells of males). Two were seen attempting to copulate with stones that vaguely resembled a tortoise (Fig. 15). In captivity, male SSB plus strange sex-toy behaviours have been reported in tortoises (Internet search using keywords "tortoise and shoe"). These cases of juvenile mounting, homosexual Davian behaviours, skeletophilia (bellow), or petrophilia illustrate that the strong sexual motivation of males can overrule accurate discrimination of appropriate sexual partners. In the nearby mainland Konjsko population, in other Hermann's tortoise populations, and in other Testudo species, uneven SR (generally unbiased or male biased) and varying population densities have been documented (Table 12). However, the combination of extremely skewed SR with very high population density and SSB was observed only on Golem Grad. We thus suggest that frequent SSB are expressed above a threshold that combines high density and skewed SR in physiologically predisposed individuals (e.g. male tortoises with high T levels).

Considering other adaptive or nonadaptive explanations does not change our main conclusions. For example, mate selection by females would reinforce the scarcity of partners for the males; the effect of practice ("Immature individuals learn ... through SSB"; Bailey and Zuk 2009) is unlikely in tortoises because sexual behaviours were never expressed by juveniles. The tortoises of Golem Grad provide the first documented example of a "prison effect" in freeranging animals and thus offer a strong support to the hypothesis of nonadaptive causation for SSB. This finding suggests that proximate factors underlying SSB are not necessarily restricted to physiological disorders or require an adaptive basis (although indirect links between nonadaptive SSB and mating success exist; [START_REF] Logue | A behavioral syndrome linking courtship behavior toward males and females predicts reproductive success from a single mating in the hissing cockroach, Gromphadorhina portentosa[END_REF]). Under conditions with strong social stimulation and a scarcity of partner, SSB may be common.

SEXUALLY ABUSIVE TORTOISES DIGGING THEIR OWN GRAVE: SEX RATIO BIAS GENERATES INSUFFERABLE SEXUAL CONFLICT

[2018, J Anim Ecol Under review, Arsovski D, Tomović Lj, Golubović A, Besnard A, Trajćeska I, Bonnet X] [2018, Biol J Linnean Soc 124: 394-402, Golubović A, Arsovski D, Tomović Lj, Bonnet X] [2017, Behav Ecol Sociobiol 71: 93-100, Golubović A, Andjelković M, Arsovski D, Bonnet X Tomović Lj] Sexual selection provides a unitary framework to study the tremendous variation in animal reproductive traits [START_REF] Andersson | Sexual selection[END_REF][START_REF] Dall | Debating Sexual Selection and Mating Strategies[END_REF]). The respective fitness interests of females and males are expressed through a continuum of mating strategies ranging from collaboration (convergent interests)

to antagonism (divergent interests) between the sexes [START_REF] Chapman | Sexual conflict[END_REF].

Strict monogamy characterized by tight cooperation between the sexes and strongly bonded pairs is rare [START_REF] Bull | Monogamy in lizards[END_REF]. In most species, males invest less in offspring production than females, generating predominantly divergent interests. Broadly, males can achieve forcible insemination via two main tactics with different evolutionary consequences [START_REF] Clutton-Brock | Sexual coercion in animal societies[END_REF][START_REF] Holland | Perspective: Chase-Away Sexual Selection: Antagonistic Seduction Versus Resistance[END_REF][START_REF] Brennan | The limits of sexual conflict in the narrow sense: new insights from waterfowl biology[END_REF]. When males are larger and stronger an evolutionary arms race of evolutionary forces between the sexes initiates the development of defensive attributes in females in order to lower mating costs [START_REF] Arnqvist | Antagonistic coevolution between the sexes in a group of insects[END_REF][START_REF] Reinhardt | Reducing a cost of traumatic insemination: female bedbugs evolve a unique organ[END_REF][START_REF] Muller | Male coercion and the costs of promiscuous mating for female chimpanzees[END_REF][START_REF] Johns | Love bites: male fang use during coercive mating in wolf spiders[END_REF][START_REF] Hare | The self-domestication hypothesis: evolution of bonobo psychology is due to selection against aggression[END_REF][START_REF] Lange | Functions, diversity, and evolution of traumatic mating[END_REF][START_REF] Michels | Reduction of female copulatory damage by resilin represents evidence for tolerance in sexual conflict[END_REF][START_REF] Peinert | Traumatic insemination and female counter-adaptation in Strepsiptera (Insecta)[END_REF]. When males cannot force insemination they usually harass females through a war of attrition (Clutton-Brock & Parker 1995) encouraging female defensive or escape behaviours, testing male quality and thereby optimizing sperm selection (Wang, Cummings & Krikpatrick 2015). Intermediate, cryptic coercive strategies and subtle female choices provide abundant exceptions and complications to this dichotomous view [START_REF] Reyer | Cryptic female choice: frogs reduce clutch size when amplexed by undesired males[END_REF][START_REF] Pizzari | Female feral fowl eject sperm of subdominant males[END_REF][START_REF] Shine | Cryptic forcible insemination: male snakes exploit female physiology, anatomy, and behavior to obtain coercive matings[END_REF][START_REF] Parker | Sexual conflict over mating and fertilization: an overview[END_REF][START_REF] Knott | Female reproductive strategies in orangutans, evidence for female choice and counterstrategies to infanticide in a species with frequent sexual coercion[END_REF]). Yet, theoretical models and empirical studies converge on the idea that at least one sex (generally both sexes) loses substantial fitness benefits from forcible insemination to permit maintenance of the mating strategy [START_REF] Parker | Sexual conflict over mating and fertilization: an overview[END_REF]. This leads to a difference in optimal mating rates between the sexes generating sex-specific evolutionary interests termed sexual conflict [START_REF] Parker | Sexual selection and sexual conflict[END_REF][START_REF] Parker | Sexual conflict over mating and fertilization: an overview[END_REF]. If one sex imposes costs on the other, then we can easily lizard population and observed that female mating costs increased with increased male bias up to the point of completely deterring females from mating and breeding. In this case male biased OSR does not only seem to lack selfregulatory mechanisms (e.g. male intrasexual competition), but can go so far as to progressively reduce female survival initiating what the authors have coined an 'extinction vortex'.

Elucidating OSR's influence on population viability is not straightforward however. This naturally imposes the question of the possible origins of such bias.

In vertebrates, literature points to several options: (i) biases from birth, such as in species with environmental sex determination [START_REF] Komdeur | Extreme adaptive modification in sex ratio of the Seychelles warbler's eggs[END_REF][START_REF] Lolavar | Effect of rainfall on loggerhead turtle nest temperatures, sand temperatures and hatchling sex[END_REF][START_REF] Pieau | Temperature variation and sex determination in reptiles[END_REF], (ii) sex-specific juvenile survival rates [START_REF] Bordier | Inter-annual variability of fledgling sex ratio in king penguins[END_REF][START_REF] Eberhart-Phillips | Sex-specific early survival drives adult sex ratio bias in snowy plovers and impacts mating system and population growth[END_REF][START_REF] Veran | Demographic origins of skewed operational and adult sex ratios: perturbation analyses of two-sex models[END_REF], (iii) sex-specific adult survival rates [START_REF] Arendt | Replicated origin of femalebiased adult sex ratio in introduced populations of the Trinidadian guppy (Poecilia reticulata)[END_REF][START_REF] Galliard | Sex ratio bias, male aggression, and population collapse in lizards[END_REF][START_REF] Réale | Female-biased mortality induced by male sexual harassment in a feral sheep population[END_REF]Székely et al. 2014b), and (iv) sex-specific local emigration and immigration rates (Millert al. 2011;[START_REF] Veran | Demographic origins of skewed operational and adult sex ratios: perturbation analyses of two-sex models[END_REF]. The causes of OSR bias are not consistent across taxa, and likely among populations. Properly untangling these possible sources requires comprehensive modelling, preferably in a natural population. This has only been achieved recently in a population of snowy plovers: adults exhibit a male biased OSR induced by male biased juvenile survival [START_REF] Eberhart-Phillips | Sex-specific early survival drives adult sex ratio bias in snowy plovers and impacts mating system and population growth[END_REF]. A result opposed to a comparative bird study where adult mortality rates were the main cause of OSR-bias (Székely et al. 2014a).

Studying the variety of possible underlying factors to OSR is crucial to better understand mating systems (Székely 2014a), population dynamics, and it may contribute to improve conservation policies [START_REF] Bessa-Gomes | Allee effects, mating systems and the extinction risk in populations with two sexes: Allee effects, mating systems and the extinction risk[END_REF][START_REF] Veran | Demographic origins of skewed operational and adult sex ratios: perturbation analyses of two-sex models[END_REF]. Here, we examine the possible contributors and consequences of OSR bias in a very dense island population of Hermann's tortoises, a species with a polygamous and coercive mating system.

Quantification of cloacae swollenness and injury levels between both localities (Fig. 16) and [START_REF] Hailey | Population density and adult sex ratio of the tortoise Testudo hermanni in Greece: evidence for intrinsic population regulation[END_REF] suggest possible female costs imposed by coercion under high population densities in this species, but to the best of our knowledge this has not been quantified. Using 10-year individual-based capture-recapture (CR) data we modelled sex-and age-specific survival rates. To interpret the outcome, we used data on the environmental risks faced by tortoises (Golubović et al. 2013a), insight on the impact of OSR-bias on their sexual habits, growth and body size variation information of all age and sex cohorts along with abundant mortality records collected in the field. Finally, by superimposing such insight against comparable data from Konjsko we try to envisage the destiny of these confined, free-ranging, island tortoises: will sexual conflict generate a system where OSR-bias is continuously exacerbated (extinction vortex) or could it gradually be buffered?

Box 2 [Shift of harassment tactic] In tortoises, males occasionally court small immature individuals (Hailey & Loumbourdis 1990). Intensive harassment can result in substantial wounds. Females from the two studied populations were under different courtship pressures. At Konjsko, injuries were typically more frequent in larger individuals and were never observed in females smaller than 170 mm SCL and 17 years old or younger (age estimated from Fig. 8 [p. 34]). Thus, intensive coercive mating was concentrated on large females at least 5 years after maturity, revealing an important buffer agespan preventing harassment of small, possibly immature females. Conversely, small females on Golem Grad Island were often wounded long before they reached adulthood (p. 36, Fig. 11), revealing a lack of body size threshold. The smallest wounded females on Golem Grad Island were estimated to be only 8 years old (Fig. 16 according to Fig. 8 [p. 34]). The high population density and strongly male-biased sex ratio on Golem Grad triggers unusually intensive reproductive activity in males. Frustrated males not only court and mount females, but also other males (including immatures), dead tortoises, empty shells and even stones (Fig. 15). These behaviours have not been recorded in other free-ranging tortoise populations (Table 12). Consequently, a very high population density and skewed OSR not only increase the likelihood that a female will be courted, but also induce a behavioural shift in male mating tactics. This shift toward immature females may entail costs but cannot generate any benefit; in this case coercive mating was maladaptive.

The origin of OSR bias was explored comprehensively, eliminating potential contributors in a step-wise manner: i) even early-life sex-ratios (p. 26, Table 7), ii) absence of sexspecific early-life survival (p. 36, Fig. 11) and iii) lack of immigration and emigration (from the island), iv) unravel the significant difference in adult survival of the sexes as the sole, albeit sufficient contributor. Perhaps we will never know how this survival gap initially came to be, but projection matrices demonstrate that it alone can swiftly bring about the current OSR-bias, initiating a vicious demographic cycle (p. 37, Fig. 12). It is important to note that young (neonate-to-nine year old) females from the Island Plateau express consistently lower survival probabilities than other young island tortoises (p. 36, Fig. 11) and Golem Grad males were observed to inflict injuries to even immature females as young as eight years old (Fig. 16). Whether very young females truly also suffer lower survival on the plateau, or that is imposed by the model is still not clear due to their low sample sizes. Nonetheless, at least on the Island Plateau [only 5% of the population is female], sexual coercion on Golem Grad maladaptively targets even immature females, or those at the onset of maturity (p. 36, Fig. 11; Fig. 16). Therefore, besides not recognizing juvenile sex-specific survival as a strong contributor to OSR-bias, we acknowledge that for some females, pressures from male sexual assaults likely start before maturity, further exacerbating the trend. The reproductive input of female tortoises is likely more demanding in terms of resources (e.g. for vitellogenesis) than male input [START_REF] Congdon | Energy Budgets and Life Histories of Reptiles[END_REF], leading to sex-specific differences in optimal mating rates and sexual conflict [START_REF] Parker | Sexual selection and sexual conflict[END_REF]). Conflict could be exacerbated under high density [START_REF] Blyth | Extreme promiscuity in a mating system dominated by sexual conflict[END_REF][START_REF] Cordero | Forced copulations and female contact guarding at a high male density in a Calopterygid damselfly[END_REF]) in Hermann's tortoises, since density promotes intensive courtship in this promiscuous reptile [START_REF] Bertolero | Testudo hermanni (Gmelin 1789) -Hermann's Tortoise[END_REF]. Unsurprisingly, 96.55±1.74 males/ha on Golem Grad trigger relentless eagerness to mate; this phenomenon is expressed to such extremes on the island that males also mount other males, dead individuals, empty carapaces, stones, etc. (Fig. 15). Conversely, sparse island females (8.88±0.85 females/ha) offer little chance for male sexual coercion to diffuse, thus leaving little room to female mate choice. OSR-bias can steer selective forces from intersexual mate choice to strong intrasexual competition (e.g. male combats) that should eventually buffer the bias [START_REF] Greenwood | Mating Systems, Philopatry and Dispersal in Birds and Mammals[END_REF][START_REF] Kvarnemo | The dynamics of operational sex ratios and competition for mates[END_REF][START_REF] Wolff | Effects of adult sex ratios on recruitment of juvenile gray-tailed voles, Microtus canicaudus[END_REF]. However, male survival is high on Golem Grad and combats occur relatively rarely (Table 5 in the appendix). Thus, where island male tortoises seem eager to eat and mate, lower female recapture probabilities suggest prudence when foraging to survive, likely in an attempt to avoid sexually charged males -apparently also a matter of survival.

Life-history trait estimates on Golem Grad seemingly point towards a scenario more to the likes of the experiments of Le [START_REF] Galliard | Sex ratio bias, male aggression, and population collapse in lizards[END_REF] and Fitze & Le [START_REF] Fitze | Operational sex ratio, sexual conflict and the intensity of sexual selection[END_REF] where sexual coercion increases female mating costs substantially, reducing or even hampering reproduction and initiating an 'extinction vortex'. Indeed, island female survival is significantly lower (0.84, CI 0.80-0.87 vs. 0.97, CI 0.96-0.98) and the few female dissections suggest a drastic difference in reproductive state between localities -island females with empty oviducts and only small follicles in the ovaries and a mainland female full of eggs and follicles of all sizes (pp. 20-21, Fig. 3 & Table 3). The constant low proportion of body reserves in all individuals (dissected males also had low fat reserves [0.0-0.3%, N=9, unpublished data]) alongside higher proportions of eggs and follicles (p. 21, Table 3), infer that variation in tortoise BCI is strongly influenced by 3) was found surrounded by nine males with an extremely injured and swollen cloaca (above) and too exhausted to escape their persistent coercive mating attempts. She was rescued, gently force-fed (sugar + water) and kept away from males, but nevertheless died two days later.

As for the females that manage to survive, other perils await -steep and high island cliffs. Golem Grad tortoises are more prone to risk taking behaviour (i.e. taking the plunge) than conspecifics from Konjsko (Golubović et al. 2013a). In our experiment, island females approached the edge of the enclosure significantly more than Konjsko females and eventually took a "hazardous" (but only available) exit, even in the absence of coercion.

Interestingly, these differences between localities disappeared when male coercion was present, yet no females from Konjsko made an exit without a push.

These experiments, supported by a significantly higher proportion of recovered female to male tortoise shells with cracked carapaces (out of all recovered shells), and four direct field observations (Fig. 17; Golubović et al. 2013a) attest to the unfortunate phenomenon of "jumping" females when cornered by coercive males on Golem Grad Island. Habitat characteristics influence locomotor performances in the Hermann's tortoise (Golubović et al. 2017), but implied intersexual differences in hesitation time prior to a risky move (Golubović et al. 2013a) and the experimental effect of coercion on otherwise tamer Konjsko females, suggest that this force has likely pushed the adventurous island behaviour a step further in females.

Unfortunately for this population, it is not only mean annual survival that has taken the toll, but also the temporal variation of this trait. In longlived animals, survival variation should be canalized (Gould & Nichols 1998) against environmental variation, thus ensuring population growth even in suboptimal conditions [START_REF] Gaillard | Temporal variation in survival of mammals: A case of environmental canalization?[END_REF]. Male island tortoises neatly conform to this rule with a variance close to zero (CI 0.00-0.02), whereas significantly higher female variance of nine percent (CI 0.03-0.14) has likely succumbed to environmental pressure brought upon by male coercion making their fate unclear (e.g. in predictable vs. unpredictable environments in [START_REF] Cayuela | Contrasting patterns of environmental fluctuation contribute to divergent life histories among amphibian populations[END_REF].

Guided by scarce literature on the discussed population-intrinsic regulation mechanism [START_REF] Hailey | Population density and adult sex ratio of the tortoise Testudo hermanni in Greece: evidence for intrinsic population regulation[END_REF][START_REF] Galliard | Sex ratio bias, male aggression, and population collapse in lizards[END_REF] we were fortunate enough to identify a natural population experiencing sexual selection under the steering wheel of OSR-bias and sexual coercion. Quantifying female costs via several life-history parameters and applying them to projection matrices we conclude that an 'extinction vortex' is likely imminent. Nevertheless, adult tortoises can linger for a long time even after the last female dies, whereas faster paced animals would have a much faster response making us question whether such demographic drifts are actually rare or the time window to witness them is sometimes very short. In lack of more insight, a likely scenario that caused this on Golem Grad Island is a recent arrival (unpublished genetic data) of these tortoises to the island with an OSR bias beyond the threshold that initiates a vortex in interaction with sexual coercion in this species; a random event could be equally likely. Regardless, in a globally changing climate, environmental sexdetermination in the Hermann's tortoise [START_REF] Pieau | Temperature variation and sex determination in reptiles[END_REF] can easily make this island's OSR scenario a widespread occurrence (e.g. [START_REF] Jensen | Environmental Warming and Feminization of One of the Largest Sea Turtle Populations in the World[END_REF] imploring further research into the identification of OSR bias and density thresholds that make a tortoise population unsustainable.

SECOND REFLECTION -TO LET IT BE OR TO PRESERVE -

Detailed life-history trait estimates and their variation in a population of tortoises from Golem Grad Island shed light on a slow, but ongoing extinction event, that could have otherwise been overlooked. Now comes the inevitable question:

"should something be done to put this process to a halt and possibly reverse it?"

Persistent SSB mating attempts have likely diluted sexual coercion from the few present females, but even so, OSR bias and density are clearly still passed the threshold that reduces female survival. Several potential activities that could

CONSERVATION IMPLICATIONS WHY AN APPARENTLY PROSPEROUS SUBSPECIES NEEDS STRICT PROTECTION? THE CASE OF TESTUDO HERMANNI BOETTGERI FROM THE

CENTRAL BALKANS [2018, Herpetol Conserv Biol In press, Nikolić S, Golubović A, Bonnet X, Arsovski D, Ballouard J-M, Ajtić R, Sterijovski B, Iković V, Vujović A, Tomović Lj] The Hermann's tortoise is "Near Threatened" according to the IUCN Red List (assessed in 2004), but because its populations are in significant decline it is also regarded as close to qualifying for "Vulnerable" (van Dijk et al. 2004). The situation is made more complicated due to the existence of two recognized subspecies across its distribution range that have faced varying threat levels and therefore enjoy different protection statuses. Namely, the western nominotypic subspecies (T. h. hermanni) is regarded as one of the most threatened reptiles in Western Europe [START_REF] Van Dijk | Conservation Biology of Freshwater Turtles and Tortoises[END_REF][START_REF] Zenboudji | Conservation of the endangered Mediterranean tortoise Testudo hermanni hermanni: The contribution of population genetics and historical demography[END_REF][START_REF] Badiane | Uncovering environmental, land-use and fire effects on the distribution of a low-dispersal species, the Hermann's tortoise Testudo hermanni[END_REF] and locally classified as "Endangered" in Spain, France and Italy [START_REF] Luiselli | Sighting frequency decreases over two decades in three populations of Testudo hermanni from central Italy[END_REF][START_REF] Vilardell-Bartino | Knowledge of habitat preferences applied to habitat management: the case of an endangered tortoise population[END_REF], as well as on the international level (European Reptile and Amphibian Specialist Group 1996). Rapid development in the west has massively contributed to its current condition, and at present day increasing threats in the Balkan Peninsula (e.g. [START_REF] Vujović | Effects of fires and roadkills on the isolated population of Testudo hermanni Gmelin, 1789 (Reptilia: Testudinidae) in central Montenegro[END_REF]) might bring about a similar fate to the eastern "cousin" (T. h. boettgeri). Long-lived species such as tortoises rely heavily on the survival of reproductive adults for population growth [START_REF] Hailey | Adult survival and recruitment and the explanation of an uneven sex ratio in a tortoise population[END_REF][START_REF] Gaillard | Temporal variation in survival of mammals: A case of environmental canalization?[END_REF][START_REF] Bertolero | Testudo hermanni (Gmelin 1789) -Hermann's Tortoise[END_REF]) and moderate persistent perturbations can imperceptibly influence adult survival. Often such pressures can only become obvious once the population has been brought to an irreversible tipping point [START_REF] Jonsson | Are Certain Life Histories Particularly Prone to Local Extinction[END_REF][START_REF] Shoemaker | Reexamining the minimum viable population concept for long-lived species[END_REF][START_REF] Badiane | Uncovering environmental, land-use and fire effects on the distribution of a low-dispersal species, the Hermann's tortoise Testudo hermanni[END_REF]) -the reality of the western subspecies. The eastern Hermann's tortoise does not benefit from a strict conservation status and its populations seem healthy (can be easily found in large numbers in the field [START_REF] Djordjević | Geographic (in-)variability of gender-specific traits in Hermann's tortoise[END_REF]), but many might well be close or at a tipping point.

Consequently, the IUCN states that "field assessments of conservation status are highly desirable" and several more relevant sources have been asking for the upgrading of the conservation status of both subspecies [START_REF] Rozylowicz | Assessing the threatened status of Testudo hermanni boettgeri Mojsisovics, 1889 (Reptilia: Testudines: Testudinidae) population from Romania[END_REF][START_REF] Djordjević | Hermann's tortoise Testudo hermanni Gmelin 1789[END_REF]van Dijk et al. 2004;[START_REF] Bertolero | Testudo hermanni (Gmelin 1789) -Hermann's Tortoise[END_REF][START_REF] Ljubisavljević | The commercial export of the land tortoises (Testudo spp.) from the territory of the former Yugoslavia[END_REF][START_REF] Ljubisavljević | Distribution patterns of Hermann's Tortoise Testudo hermanni Gmelin, 1789, in the region of former Yugoslavia (Testudines: Testudinidae)[END_REF].

Here 13).

In general, no 'normal' simulations predicted extinction, but when disturbances were applied the situation changed dramatically (Figure 18); for longer elaborations of the results and graphical presentations of the PVAs of all five populations please see Nikolić et al. (2018). For Golem Grad, PVAs merely confirm the results of the previous chapter, but this peculiar population is not representative of Hermann's tortoises from the Balkans. Desirable tortoises from the peninsula are likely most heavily affected by the pet industry. Figure 18 demonstrates the unfortunate fate of a Serbian population if allowed harvest quota of adult individuals (200 every three years) are continuously reached. This figure can easily be applied to Konjsko and Golem Grad tortoises whose dense populations offer easy collection by poachers besides legal harvest not being allowed. Easy access from Western Europe, where most animals end up, make [START_REF] Hailey | Changes in the status of tortoise populations in Greece 1984-2001[END_REF]]. We plugged in actual field data (Table 13) and data from literature (Hailey and Loumbourdis 1988;[START_REF] Hailey | Adult survival and recruitment and the explanation of an uneven sex ratio in a tortoise population[END_REF][START_REF] Hailey | Changes in the status of tortoise populations in Greece 1984-2001[END_REF][START_REF] Bertolero | Testudo hermanni (Gmelin 1789) -Hermann's Tortoise[END_REF][START_REF] Couturier | Factors determining the abundance and occurrence of Hermann's tortoise Testudo hermanni in France and Spain: Fire regime and landscape changes as the main drivers[END_REF] For more details on the methodology please see Nikolić et al. (2018).

this a huge problem [START_REF] Ljubisavljević | The commercial export of the land tortoises (Testudo spp.) from the territory of the former Yugoslavia[END_REF]: overview in Table 13). Captive breeding programs, legal in Macedonia and Serbia exacerbate the issue, since farms easily act as platforms to obtain "legal permits" for the transportation of wild caught tortoises. Dealing with these issues, while still preserving their habitats and the mosaic structure of the landscapes still present in their Eastern range can thoroughly benefit the species [START_REF] Livoreil | Distribution of the Endangered Hermann's tortoise Testudo hermanni hermanni in Var, France, and recommendations for its conservation[END_REF][START_REF] Rozylowicz | Habitat selection and movement ecology of eastern Hermann's tortoises in a rural Romanian landscape[END_REF][START_REF] Badiane | Uncovering environmental, land-use and fire effects on the distribution of a low-dispersal species, the Hermann's tortoise Testudo hermanni[END_REF]. Making such endeavours a priority can best be achieved by assessing their legal status both locally and internationally.

Demographic data and the assessment of threats suggest that locally the Hermann's tortoise should be considered "strictly protected", whereas according to IUCN T. h. boettgeri should internationally be classified as "Vulnerable". International organizations have invested huge amounts of resources in the developing (e.g. Macedonia) and third world in order to preserve biodiversity. The corrupt nature of most of these areas require a cascade of expensive international actors to implement projects. By the time resources reach implementers, such as field biologists, there is only a trickle of the original resources and surely not enough to promote long term studies and sound conservation. This system has promoted the artificial separation of research from conservation.

My own experiences getting resources to implement fundamental research have perhaps made me bitter. The incredible lengths one needs to go in order to justify research projects, such as insistently having to introduce the terms "saving", "conserving", "raising awareness" is discouraging to say the least -after all, no conservation effort has ever "saved", "conserved" or "raised awareness" in a matter of one year and several thousand euros. Fundamental research needs to become the new "awareness raising" or "saving" in conservation, and resources need to therefore be distributed to projects with long-term effects, rather than short-term good-onpaper plans.

Fortunately, systems such as Golem Grad Island offer easy collection of dense data that can in turn be put to good conservation use without preconceived notions.

Applied conservation should only be the inevitable and likely unavoidable side-effect of research, rather than a short term must! 9. BIBLIOGRAPHY Since growth coincides with the period of active thermoregulation (Bertolero et al. 2005), we excluded hibernation from growth calculations. The onset and the end of hibernation were obtained in the field from 10 individuals fitted with temperature data loggers in late summer in 2010 and 2011 and recaptured the following spring (unpublished data). On average, the duration of hibernation was 190 days. We considered that the activity period elapsed from the 22 nd of April to the 14 th of October (175 days).

Individual variation in size and growth

The 'individuals of known age' dataset was randomly resampled 10,000 times using parametric bootstrapping and mean asymptotic size was estimated for each resample. Differences in asymptotic size between resamples would likely be driven by shifts in individual trajectories from the original sample picked up more frequently by chance by the bootstrap procedure.

As for the individuals of unknown age, a smaller subsample of tortoises that had been encountered and measured during at least 5 consecutive years was used to build individual-based growth curves and estimate individual-based asymptotic SCLs. This way the population's full potential for growth variation could truly be appreciated. After sexual maturity Hermann's tortoise growth decreases linearly as a direct function of size, a pattern that fits well to Bertalanffy's model (Hailey & Coulson 1999). We therefore used Bertalanffy's In Konjsko, in the same respective order: 297, 325, 226 and 216 measurements were collected. Additionally, in order to account for pseudo-replication from repeated measurements, individuals were accounted for as a random factor in the generalized linear mixed models using the package 'nlme' [START_REF] Pinheiro | Nlme: Linear and Nonlinear Mixed Effects Models[END_REF]).

Competitive models were ranked according to AIC (Burnham & Anderson, 2002).

Finally, predictions based on the best-fitted model were made using the under one field observation i.e. event), thus at first capture (initial departure state) individuals could be adult with high or low recapture probability (A+ and A-, respectively). They may then survive from year t to t + 1 (Table S1, matrix Ф)

with probability ф A+/-or they may move to a just-dead state ( †) with probability 1 -ф A+/-. Similar to other recovery models [e.g. [START_REF] Schaub | Assessing the relative importance of different sources of mortality from recoveries of marked animals[END_REF])],

individuals whose empty shells were recovered moved to an absorbing longdead state (RS). The states thus being A+, A-and RS. The event matrix P (Table S1) defines events (field observations):

A+ A- RC † NO A RC A+ ф A+ 0 1- ф A+ 0 A+ 1-p A+ p A+ 0 A- 0 ф A-1-ф A- 0 A- 1-p A- p A- 0 RC 0 0 0 1 DR 1- p DR 0 p DR † 0 0 0 1 † 1 0 0
The model selection procedure entailed the dropping and addition of parameters starting with recapture probability and followed by survival, until a combination with the lowest AIC (Akaike information criterion) was found (Burnham & Anderson 2002). The initial model was: Ф[sex*site],

P[sex*site*het*t].
At first capture, individuals depart from all states but dead. Subsequently, they can annually transit between states following five successive transition matrices: survival from t to t+1 (matrix Φ, Table 4A), dispersal between sites, given the individual survived (matrix Y, Table 4A), and change of recapture heterogeneity class given the individual survived and changed site (matrix F, Table 4A). Note that for easier implementation, Y is a 9*17 matrix where eight departure states can transit to a "stay" or "moved" state. F is thus a 17*9 matrix, that allows "moved" individuals to change recapture probability class (since we suspect recapture heterogeneity to be related to trap location we assumed that "stay" individuals wouldn't change recapture heterogeneity class). Nonetheless, since no tortoise changed site and all were visually searched for (instead of using traps which could promote change of recapture heterogeneity class) matrices Y and F were not parameterized. Finally, individuals can be recaptured or not. For easier implementation, this event matrix was split into two matrices, one allowing to model recapture probability given the states (matrix P, Table 4A), the other to estimate the probability of correctly sexing individuals (matrix S, Table 4A).

Estimating parameters between nine age classes, sexes, and sites requires very dense and large datasets in order to obtain robust and precise estimates.

This dataset came very close to meeting these requirements. Nevertheless, only one individual was captured as one year old; covariates (linear, logarithmic and quadratic) were implemented on the age-survival relationship in order to obtain inestimable parameters and streamline estimates. TABLE 4A. Elementary matrices: i) survival matrix Ф, f is the probability to survive from t to t+1; ii) dispersal matrix Y, y is the probability to be faithful to the site of first capture from t to t+1; iii) change of heterogeneity class matrix F, f is the probability of reaching the high recapture probability class; iv) first event matrix P, p is the probability of being recaptured, conditional on the departure states (Table 3A); v) second event matrix S, s is the probability to assess the sex of the individual, 0 -unobserved, 1 -observed as male on the Plateau, 2 -observed as female on the Plateau, 3 -observed as unsexable on the Plateau, 4 -observed as male on the Beach, 5 -observed as female on the Beach and 6 -observed as unsexable on the Beach. displaying active HSB or involved in male-to-male combat), SA with the same sex 123 (SSB, individual observed in an active homosexual behaviour, essentially a male mounting another male, thus excluding combats), and dead ( †). All states can then transition via the survival matrix Ф (Table 7A), and given that they survive they can either stay in their state or transit into an either passive or sexually active (homosexual or heterosexual) state via matrix Y (Table 7A). Detection probability was modelled according to sexual behaviour in matrix P (Table 7A).

dependencies for survival. Finally, we tested for site dependency on transition probabilities between behavioural states, thus testing for an effect of OSR and density. Pictures were visually scored for cloacal swollenness (0: not swollen, 1:

slightly swollen, 2: clearly swollen, 3: extremely swollen, Fig. 1A) and for injury severity (0: no injury, 1: several injuries, 2: severely injured, Fig. 1A). Since the cloaca is soft and exhibits a relatively labile shape, it is not measurable by classical morphometric methods, thus we used visual ranking [START_REF] Hailey | Adult survival and recruitment and the explanation of an uneven sex ratio in a tortoise population[END_REF]). To minimise the subjective nature of this method, photographs were randomly sorted into 15 sheets with 10 to 25 pictures in each. They were blindly categorised by two observers independently. In most cases, both scores were in agreement (swollenness: 49% total agreement, 44% slight disagreement, 7% partial disagreement, 0% full disagreement; injury levels: 64% total agreement, 35%

partial disagreement, 1% full disagreement). Importantly, the overall proportions provided by each observer were either very close considering cloacal injuries or provided relatively similar trends for swollenness (Table 1). For most analyses we used average values from the double scoring. This generated seven levels of swollenness (0, 0.5, 1... 3) and five levels of injury severity. For conciseness, we also performed several analyses with a reduced level of scores. For example, using only three injury levels: 0 (0 -0.5 pooled), 1 (1.0), and 2 (1.5-2.0 pooled).

Our sample included 208 individuals and 259 pictures (i.e. 51 pseudoreplicates). Females sampled more than once were captured at different months or different years. Consequently, a substantial amount of time elapsed between captures and their status changed (improving or worsening) in 79% of the cases.

Consequently, re-sampling several individuals did not change the results significantly (analyses were nonetheless performed using all pictures, N=259, versus after random selection of pseudo-replicates, N=208). In practice, swollenness and injury levels provided similar trends (Fig. Plateau to Beach), broken shells very likely implying a previous fall from the cliffs; at four occasions falling tortoises were directly observed in the field (Golubović, Arsovski, Ajtić, Tomović, & Bonnet, 2013). The proportion of females vs. males that have died after taking the plunge (i.e. broken shell) vis-à-vis the total number of dead recoveries were compared using a chi-2 test with Yates correction for small samples. (example videos of both scenarios in Appendix) was noted. Primarily, the proportions of females from both localities that took the plunge vs. those that stayed in the enclosure for 30 minutes were tested in both scenarios (alone and with five males). Finally, the times the edge of the enclosure was approached in both scenarios was compared between localities. All comparisons were tested using a chi2 with Yates correction for small samples in R v0.99.879 (R Core Team 2014). epitestosterone: 0.7%; progesterone: 0.07%). The assay's sensitivity was 7.8 pg by tube, that is, 156 pg/mL. Intra-assay and interassay variations were 6% and 12%, respectively.

Sexual behaviours

In order for precise behaviour to be assigned to testosterone (T) levels, blood samples were rapidly taken (less than three minutes on average, range 0.2-7 minutes) on a random subset of the adults monitored in 9. 1.3.1. In the field it was ensured that individuals did not detect the observers (i.e. no sign of disturbance) at capture. This fast procedure limited the possible rapid negative effect of stress on steroid levels [START_REF] Michel | Effect of a brief stress on progesterone plasma levels in pregnant and non-pregnant guinea pigs[END_REF], thus T levels and behaviours were considered to have been recorded simultaneously. Using the same method blood samples were collected from Konjsko as well. In total, 283

  REFLECTION & RELEVANCE ............................................................................... 9. BIBLIOGRAPHY ............................................................................................................... 9.1 THESIS REFERENCES................................................................................................. 9.2 ADDITIONAL RELEVANT (CO)AUTHORED REFERENCES ............................................ 1A. APPENDIX .................................................................................................................. 1.1 Statistical analyses............................................................................................... 1.1.1 GROWTH ...................................................................................................... 1.1.1.1 Age-specific variation in body size ......................................................... 1.1.1.2 Population and cohort mean asymptotic sizes......................................... 1.1.1.3 Individual variation in size and growth ................................................. 1.1.2 BODY CONDITION ......................................................................................... 1.1.2.1 Fecundity and mating costs ................................................................... 1.1.3 SURVIVAL, POPULATION SIZE & SEX RATIO ..................................................

  ADDITIONAL GOLEM GRAD ISLAND INFO.................................................... 1.1.8 BIBLIOGRAPHY ............................................................................................. The entire manuscript follows the general form of a classical scientific paper in order to avoid the approach of simply piling together published papers, in a more or less artificial manner. From the very beginning, a common denominator (islands) was chosen to act as a binding agent, compiling the diverse published and unpublished material of this doctoral thesis into a singular product with a (hopefully) natural flow. The introductory chapter named "Islands as vectors of insight" announces a dichotomy which will resonate throughout the manuscript. This is most evident in the discussion, which has been split into three chapters. The first two ("run-of-themill ecology: islands as facilitators of biological insight enquiry" and "from run-of-the-mill to out-of-the-way: islands as vectors of peculiarities and mediators of applied research") parallel the introduced dichotomy, and are followed by a seemingly detached chapter on the conservation of the used model system. I hope to have overcome this detachment in the final segment ("broad reflection & relevance") where I briefly reflect on all presented and discussed results and attempt to melt them into an argument against the artificial separation of conservation from fundamental research.

  Life Project "Conservation of priority bird species in Lake Mikri Prespa" (Number LIFE2002NAT/GR/8494) implemented between 2004-2007 and based on fundamental research and cooperation with the local community managed to triple the surface area of wet meadows and eventually saw the return of breeding Glossy Ibises, and now Mikri Prespa holds the largest breeding population of Dalmatian pelicans in the world ("Annual and final Project Reports," 2007). Unfortunately, not many examples are so encouraging -a recent reintroduction endeavour of 11 Eastern black rhinos resulted with the death of all individuals because of lack of adaptation period and salt water poisoning, all a result of failure to follow instructions based on fundamental research ("Translocated rhinos die in Tsavo East | Save the Rhino International," 2018).

FIGURE 1

 1 FIGURE 1. Lake Prespa and both study sites (outlined in yellow) in respect to the Balkan Peninsula (top right; area in red square enlarged). AL -Albania, GR -Greece, MK -Macedonia; white lines represent country borders. Image from Google Earth Pro7.3.1.4507 (64-bit).

2. 3

 3 STUDY POPULATIONS AND SAMPLING At both localities standardized capture-recapture (CR) studies were set up. Annually 2-18 people sampled both localities during 7-35 days assembled between one (e.g. one seven-day session in July 2015) to five (e.g. five days each month between May and September in 2016 and 2017) monthly field sessions. Overall, on Golem Grad 32 field sessions adding up to 195 search days enabled us tо process 1,839 individuals, amassing 14,119 recaptures. In Konjsko 48 search days during 22 field sessions enabled the collection of 595 recaptures from 887 individuals.

  ) were recorded first. Subsequently individuals were sexed if mature (a subsample of immature individuals became sexually dimorphic throughout the study period), aged when possible, measured for straight carapace length (SCL) with callipers, weighed (BM), and permanently marked using a notche-code on the marginalscutes (Right; Stubbs et al. . Individuals were rapidly released at the place of capture. After death the carapace takes substantial time to disintegrate and the scute marks often remain visible on the underlying bony tissue. This offers the opportunity of locating dead individuals and identifying them as recovered carapaces.

  results have been organized to resonate the separation of potential benefits of island research introduced in chapter 1 (from run-of-the-mill ecological insight enquiry to island-specific peculiarities, p. 1) and the broad questions raised at the end of the chapter.Sections 3.1, 3.2 and 3.3 quantify run-of-the-mill population-mean ecological parameters of Golem Grad Hermann's tortoises, each section eventually moving from run-of-the-mill to more detailed individual and/or age-specific considerations. Sections 3.4 and 3.5 move into the exploration of island peculiarities, exploring tortoise behaviour, from agility to sexuality via experiments and a behavioural CR framework. Finally, 3.6 adds a physiological backbone to some aspects from the previous sections. 3.1 GROWTH Among 1,830 marked individuals on Golem Grad Island at the time of analysis, 289 were aged (of which 113 could a posteriori be sexed-28 females, 85 males) providing 1,072 body size measurements (of which 605 belonged to individuals that could a posteriori be sexed-139 females, 466 males). This subsample constitutes the individuals of known age group. In the unknown age group, 845 marked tortoises were recaptured once or more, providing a total of 4,024 body size measurements (2,012 annual size increments). Among them, 55 females and 790 males, respectively, provided 122 and 1,890 incremental measurements. Some of these individuals (N = 97, 8 females, 89 males) had been encountered for at least five consecutive years and could thus be used to build individual-based growth trajectories. Mean adult male SCL = 171.4 mm (median = 173.3 mm) and mean adult female SCL = 173.6 mm (median SCL = 173.0 mm). The largest individual measured was a male of 218.2 mm SCL; the largest female measured 211.1 mm SCL. Both of these individuals are part of a subsample of 121 individuals with extremely smooth shells (i.e. very old), the smallest being 155.5 mm long. The smallest individual on the island measured 32.7 mm.

  2), but due to the overly generous estimates of the von Bertalanffy model (Hermann's tortoises cannot reach 500 mm in SCL, unless perhaps hormonal implants are used) we retained the logistic model for the sex-specific analyses. This subset contained one-to 15-year-old individuals of both sexes and proposed similar asymptotic sizes in females and males (SCLA ± 1 standard error [SE] = 178.1 ± 8.0 mm vs 172.4 ± 4.6 mm, respectively; p. 34, Fig. 8), suggesting that before maturity and during the first years after its onset, body size and growth rate do not differ considerably between the sexes.

FIGURE 2 .

 2 FIGURE 2. Distribution of estimated individual asymptotic sizes of Hermann's tortoises from Golem Grad Island against estimated population and sex-specific mean asymptotic sizes from Table 2. Females are marked with filled circles and males with open circles. To facilitate comparison, ranges of population and cohort mean asymptotic sizes (±SE) are displayed with four horizontal lines above the bell curve. These lines encompass a limited range of variation, accentuating the wide potential for individual asymptotic sizes

FIGURE 3 .

 3 FIGURE 3. Dissection of a fecund female from Konjsko (Female K in Table3)

FIGURE 4 .

 4 FIGURE 4. Sexual differences in the temporal variance of annual survival of adult Hermann's tortoises (SCL>130mm) from Golem Grad Island.

FIGURE 5 .

 5 FIGURE 5. Annual re-sighting probabilities (mean ± SE) of adult male tortoises as a function of their behaviours. A) Active heterosexual refers to males courting females or involved in male-to-male combats; Active SSB refers to males courting other males (e.g. mounting); Sexually inactive includes individuals observed: a) inactive (e.g. resting), b) active but not involved in sexual activity (e.g. feeding), and c) sexually passive (e.g. mounted) (see methods). B) Annual probabilities for a male in year t (sexually inactive) to engage in SSB in year t+1 in each of the two subpopulations of Golem Grad (mean ± SE).

FIGURE 6 .

 6 FIGURE 6. Mean plasma levels of testosterone (± SE) and sexual behaviours in randomly sampled free-ranging adult tortoises from Golem Grad island (circles, left panel) and from Konjsko (diamonds, right panel). Numbers above symbols stand for sample sizes. Males found alone (ALONE) or mounted by another male (PASSIVE SSB) were considered as sexually passive (grey circles and grey diamond). Males mounting another male (ACTIVE SSB), mounting a female (HETERO MATING) or during male-to-male combat (COMBAT) were considered as sexually active (black circles and black diamond). Females (open circle and diamond) were not observed sexually active. Note that SSB were observed only on Golem Grad. Strong sex differences and population effects were observed (see text for details). Letters denote significance differences among groups of males.

FIGURE 7 .

 7 FIGURE 7. Distributions of body sizes (straight carapace length, mm) within each of the first 9 years of Hermann's tortoise (Testudo hermanni) life from Golem Grad Island. Each curve stands for one age class from 1-to 9-year-old individuals (from left to right). Each circle represents the measurement collected in individuals of known age (several individuals were recaptured over years and are represented in more than one cohort, see text for details). Two distribution shifts (arrows) separate three main age cohorts. They are, respectively, indicated in black (1-year-old individuals), white (2-to 4-year-old individuals), and grey (5-to 9-year-old individuals)

FIGURE 10 .

 10 FIGURE 10. Quartiles and spread of model predictions based on the best-fitted model describing variation in body condition indices (BCIs) among Golem Grad Island (GG) and Konjsko village (K) adult male and female Hermann's tortoises. Filled circle (Konjsko) and squares (Golem Grad; square at value 4.7 represents two individuals) represent the four dissected females from Table3.

FIGURE 11 .

 11 FIGURE 11. Estimated age-specific mean survival probabilities and 95% CIs of young Hermann's tortoises from Golem Grad Island, Macedonia obtained from a discrete model (Model rank 9, Table 6, p. 25), superimposed against the estimates and 95% confidence spread of mean age-specific survival probabilities of two separate cohorts (females from the Plateau, and both sexes from the Beach along with males from the Plateau) from the same population obtained from the best-fit covariate model (Model rank 1, Table 6, p. 26).

FIGURE 12 .

 12 FIGURE 12. Simulated adult OSRs from projection matrices based on age-and sex-specific survival estimates from Golem Grad Island (section 3.3.2); thick grey line represents current island OSR estimate (±CIs). Simulations differed in initial age of sex differences in survival: at eight years-old -full line; at 10 years-old -dashed line.

FIGURE 13 .

 13 FIGURE 13. Plasma testosterone (T) levels of Hermann's tortoises from Golem Grad Island before maturity (< 130mm SCL), at its onset (range of body sizes marked by the grey striped area according to literature), and after (> 150mm SCL). Empty circles are unsexed supposedly juveniles, grey circles are males and dark rhombi are females. Sexing occurred at point of plasma extraction or a posteriori. Dashed line represents the point at first T level increase from the baseline in males.

  Substantial perturbations occurring during critical phases of rapid growth are expected to have a strong definitive impact on adult size(Rosello-Diéz and Joyner 2015). Multiple interactions between the sexes, the genes, and the environment mediated by complex physiological regulations underpin the resulting interindividual (or between cohorts and inter-population) variability in growth rate[START_REF] Badyaev | Growing apart: an ontogenetic perspective on the evolution of sexual size dimorphism[END_REF][START_REF] Lui | Mechanisms Limiting Body Growth in Mammals[END_REF] Rosello-Diéz & Joyner 2015).[START_REF] Lummaa | Early development, survival and reproduction in humans[END_REF] reported various negative effects of unfavourable conditions (e.g. nutritional stress) during early development on many human adult traits.Nevertheless, the expected impact on adult body size was less documented. Overall the possible influence of environmental factors on the most sensitive periods of juvenile growth is an open question in free-ranging animals.

Fig. 7 )

 7 Fig.7) at which point dynamic heterogeneity seems to take over. This stage lasts a staggering ~8 years(1,400 GD; p. 34, Fig. 8) during which, a tortoise's more relaxed attitude towards its surroundings may lessen the constraints on size variation, promoting idiosyncratic growth trajectories. The wide range of estimated asymptotic sizes (162.8 ± 6.2 mm to 189.4 ± 6.4 mm) from bootstrapped datasets from the individuals of known age supports this idea. Meanwhile, opportunities, perturbations in the environment, or lack thereof, fuel individual variation in size progressively blurring the size distinctions between age classes -a notion well illustrated in Figure7(p. 34) by the progressive flattening and finally overlapping of bell curves between the ages of five and nine. This sudden

  very onset) in two chelonian species (the European pond turtle [Emys orbicularis] and the Hermann's tortoise). The pond turtle dataset adds relevant comparative insight important to better grasp the results for the model species of this thesis (the Hermann's tortoise), thus instead of omitting these data, prior to the discussion I have inserted a brief description of the studied population of European pond turtle and its study site (Box 1requires robust demographic analyses based on thorough insight on these traits (Heppel 1998; Enneson & Litzgus 2008).

Box 1 [

 1 European pond turtle population and study site] This terrapin inhabits a broad range of habitats across Europe, northern Africa and western Asia. Nevertheless, it is often locally endangered and even extinct[START_REF] Fritz | Conservation actions for European pond turtles -a summary of current efforts in distinct European countries[END_REF]. The European pond turtle is largely impacted by diverse anthropogenic factors such as habitat loss, regulation of rivers and shoreline development that homogenize habitats and fragment populations[START_REF] Rogner | European pond turtle Emys orbicularis[END_REF].During 16 years(1997)(1998)(1999)(2000)(2001)(2002)(2003)(2004)(2005)(2006)(2007)(2008)(2009)(2010)(2011)(2012), a total sampling hand-capture effort of 598 hours and 6,158 trap-days in the Natural Reserve of Tour du Valat (Camargue, France, 250 ha 43°30'N, 4°40'E) resulted in 749 captured

Fig. 8 &

 8 Table 10, with a shell not yet capable of providing the stiff safety that it will ultimately bring. This insecurity along with the absence of parental care has resulted with baby tortoises that are very wary of their surroundings and forage and explore only to acquire the bare resources for survival and growth, therefore only slowly picking up growth speed until two to three years old (Fig.8, p. 34). This threshold is then marked with a sharp increase in the potential of age-specific body sizes (Fig.7, p. 34), likely facilitated by an acquired knowledge of the surrounding environment. Age-specific habitat-use and dispersal data would give even more support to these notions. Nevertheless, the soon to come survival-plateau (four to five years old, Fig.11, p. 36) and an increase in growth speed (~800 GD[4.6 years], Fig.8, p. 34) imply an acquired efficiency in obtaining resources and therefore efficient habitat use. This is likely supported by confidence gained from a finally hardened shell.

  certainly does not apply to every individual, species-wide. Some individuals are already 120mm long at seven years of age (Fig.7, p. 34), whereas others either grow extremely slowly (with an asymptotic size of 150mmSCL, Fig 9, p. 35) or maintain a steady slow growth rate after maturity(SCLA > 200cm, Fig. 9, p. 35;

  Grad's quasi-experimental natural situation allowed for the investigation of one of the main nonadaptive hypotheses reviewed by[START_REF] Bailey | Same-sex sexual behavior and evolution[END_REF]: The "prison effect" where "depriving individuals of members of the opposite sex causes them to engage in sexual interactions with members of the same sex." This notion received support in a recent review on insects studied in captivity: The paucity of sexual partner (i.e., one sex kept in isolation) combined with high population density and exposure to sexual chemical stimulation is assumed to trigger SSB[START_REF] Scharf | Same-sex sexual behavior in insects and arachnids: prevalence, causes, and consequences[END_REF]. However, comparable data are lacking in vertebrates or in natural populations. In the current study, a strong spatial and population contrast allowed us to explore the effect of environmental (female scarcity) and physiological (T levels) factors on the high SSB frequency exhibited by free-ranging males. Seven years of data from Golem Grad seem to point out to a scenario where SSB is triggered by specific environmental factors and where adaptive explanations play a limited role.

FIGURE 15 .

 15 FIGURE 15. (B) A male mounting (+ vocalization) another male, himself mounting a juvenile male (left) (photographed by A.G.). (C) A male mounting a stone (centre) (photographed by A.G.). (D) A male mounting a female (right) (photographed by X.B.).

FIGURE 16 .

 16 FIGURE 16. Relationship between cloacal injury level (white, grey, black pattern) as a function of body mass (y-axis) and body size (x-axis) recorded in two populations of freeranging tortoises (total sample N = 208): Golem Grad (upper panel, N = 69) and Konjsko (lower panel, N = 139). For clarity, only three broad categories of injury levels are displayed: open circles for females without or with moderate injury (0-0.5), grey for average level (1) and black for strong injuries (1.5-2). The grey area indicates the range of body sizes at which maturity occurs in this species. The dashed vertical line, which indicates the minimal size for average injury level recorded in Konjsko females, facilitates comparisons between the two populations.

  variation in reproductive state (in females) rather than body reserves. Dissected island female BCIs are within or beyond the lower quartile of island female BCIs (p. 36, Fig. 10) suggesting our non-random dissection sample consists of worstaffected females. Nevertheless, Golem Grad female BCIs are indistinguishable from those of the males of either population [females of the Testudo genus are the larger and heavier sex (Bonnet et al. 2001; Willemsen & Hailey 2002)last dissected female on the island embodies this unfortunate scenario: female GG 3 (p. 21, Table

FIGURE 17 .

 17 FIGURE 17. Three individuals that had fallen from the cliff on Golem Grad island and suffered considerable damage on their carapaces. Top individual was already dead at point of encounter. Bottom individuals were found alive. Bottom left individual (female) was found dead two months after the encounter.

  ameliorate the situation come to mind: (i) lower OSR bias by removing males /adding females, (ii) reduce male coercive mating attempts (e.g. by chemically castrating them), or (iii) physically keep most males from reaching females andsexually not yet dimorphic immatures (e.g. by fencing them out). Exploring whether any attempt would increase female survival is an overwhelmingly exciting contemplation, but such meddling should not be taken lightly. If enough traction is to be received from local stakeholders (National Park, municipality and local residents), individual based monitoring should not only continue, but be done under even higher scrutiny. This way insight can be gained on the recuperation process from a thorough life-history perspective, and possible unwanted side-effects would be noted and taken care of in time.

  of the oldest (>25/30 years, possibly even around 50 years old; this species' longevity is still very questionable) tortoises (N>100) on the island have Arabic numbers engraved on their plastrons suggesting an organized introduction event. Earliest reliable verbal records of tortoises on Golem Grad date to the 80 s , thus this hypothetical event must have happened during Yugoslavia. At the time the island laid in a strict military controlled border area making the lack of any written records or confessionals from local residents and the National Park of organized activities a complete mystery.

Box 3 [

 3 Population Viability Analyses] Population viability simulations are a relatively rigorous tool used in species conservation, offering insight into population dynamics with possible cascading effects on policy making [for another example on the Hermann's tortoise please see Hailey and

  into the software VORTEX(version 10.1., Lacy and Pollak 2014) and established population baselines, after which we ran parallel simulations with appropriate site-specific threats. Simulations were run for 100 and 1,000 years and carrying capacities (K) were estimated by scaling populations against the very intensively surveyed population on Golem Grad Island.

FIGURE 18 .

 18 FIGURE 18. Select PVA simulation outcomes (y-axis: population size) over 100 years (x-axis: time) for Golem Grad Island (bottom) and Trstenik (top) under baseline circumstances (left) and with disturbances (right, legal harvest and increased female mortality in Trstenik and on Golem Grad, respectively)

  growth model [SCLt = SCLA -((SCLA -SCL0) e -kt )] where individual estimates of SCLA were obtained through an iterative non-linear regression using the sexspecific value for the growth constant k (from the analyses of individuals of unknown age) as constrained value. The first capture occasion was treated as growth day zero, thus the estimate of SCL0 represented the expected size of the individual at the day of first capture 1.1.2 BODY CONDITIONThe following analyses were performed on all individuals with SCL >130mm from both localities. Each individual's body mass ratio to SCL (body condition index[BCI]) was extracted at each point of re/capture. Variation in BCI was modelled as a response to the variation in the additive and interactive effects of sex and locality.Each individual was encountered and measured 5.0 times on average on Golem Grad and 1.6 times in Konjsko. It is important to note that these measurements were distributed almost equally between seasons (spring [April and May] and summer [June, July and August]) and sexes: 3250 and 3448 males, and 233 and 206 females were encountered and processed during spring and summer months, respectively.

1

 1 Leslie matrix for Hermann's tortoises from Golem Grad Island. 0.5 is initial OSR; f fecundity; s1 survival of one-year-olds; s7 survival of seven-year-olds; s8 survival of eight-year-olds; s9 survival of nineyear-olds; s10 survival of ten-year-olds; s1(m/f) are used to simplify the matrix for demonstration purposes, and they denote all survival values between the ages of two and eight. Behavioural data in a CMR frameworkThe following analyses are based on a dataset collected between 2008 and 2014 on Golem Grad island during 13 field sessions adding up to 137 search days. 7,829 recaptures were collected from 1,208 adults. All tortoise behaviours recorded in the field were grouped into four states of sexual behaviour (see Table5Afor details): sexually inactive or sexually passive (SP, individual exhibiting no sexual behaviour or passive during sexual behaviour), sexually active (SA, individual

1. 1 . 4 . 2

 142 Sexual coercion (index of cloacal damage)Data were collected from mature and presumably immature (82<SCL<150) females from both localities. Only small individuals that could be sexed were retained. Field surveys were performed in May, June and July 2016 and 2017. A photo of the cloacal region of each female was taken by gently pulling the tip of the tail (Fig.1A). Possible wounds in the supracaudal area were not clearly visible from photographs and were not included in the analyses. Some females were captured and photographed two or three times. The Golem Grad sample included 69 individuals and 101 pictures (May N=51, June N=27, and July N=23) whereas 139 individuals and 158 pictures were collected in Konjsko (May N=22, June N=111, and July N=25).

  Photographs of females cloacal regions: normal cloaca (F), extremely swelled (S), and severely injured (I); and a photo male's long horny tail (M).101x108mm (300 x 300 DPI)

FIGURE

  FIGURE 1A. Photographs of female's cloacal regions categorised for swollenness (S) from 0 to 3, and injury level (I) from 0 to 2. Female's normal cloaca (F) and male's horny tail (M, Photographed by X.B.).

Figures

  Figures S and I represent highest levels of swollenness and injury, respectively.

FIGURE

  FIGURE 2A. Comparison of the prevalence (frequency, y-axis) of sexual harassments between the two neighbouring tortoise populations. Two proxies of coercive mating in females were used (x-axes): levels of cloacal swollenness (upper panel) and levels of cloacal injuries (lower panel). See text for details and statistics.

  2A). Indeed, the average values of swollenness positively correlated with injury scores (Spearman rank correlation Rs=0.39, N=259, p<0.05 [Rs=0.41 discarding pseudo-replicates]), simply because injuries entail tissue inflammation. Yet, injury scores likely better reflect the intensity of damages caused by males. For conciseness we emphasized injury levels results. Several continuous variables were not normally distributed (e.g. SCL); Box-Cox transformations were used. The resulting Henry's probability plots revealed linear patterns 1.1.5 LOCOMOTOR PERFORMANCE, HABITAT TYPE & SEXUAL COERCION 1.1.5.1 Steep cliffs, carapaces & swift escapesNoticeable shell damage(breaks, cracks, blood, etc., Fig. 17

  ) are always carefully described. Records were matched against locality change (e.g. Island

1. 1 . 5 . 2

 152 FIGURE 3A. Tortoise test enclosure (brightened) on Golem Grad island with opening facing abrupt fall.

1. 1 . 6

 16 PHYSIOLOGICAL FRAMEWORKBlood samples (100-300 µL, adjusted to tortoise body size) were taken during activity time (morning and afternoon) from the jugular vein or cervical sinus using very small needles (27-30 G) and slightly heparinized 1-mL syringes. Blood was centrifuged in the field, plasma samples were immediately stored in liquid nitrogen, and then at -25 °C in the laboratory until assays. Plasma T levels were measured by radioimmunoassay at the CEBC[START_REF] Lagarde | Plasma steroid and nutrient levels during the active season in wild Testudo horsfieldi[END_REF] on 50 µL of plasma after diethyl ether extraction (efficiency 0.93±0.1, standard deviation [SD]). Cross-reactivity of the specific antibody (Sigma Laboratory) with other steroids was low (B/B0: 5α-dihydrotestosterone: 17.8%; 5β-androstene-3β, 17βdiol: 1.4%; 5α-androstene-3β, 17β-diol: 1.2%; androstenedione: 1.4%;

  LOCOMOTOR PERFORMANCE, HABITAT TYPE & SEXUAL COERCION.............. .1.6 PHYSIOLOGICAL FRAMEWORK .....................................................................

1.1.5.1 Steep cliffs, carapaces & swift escapes .................................................... 1.1.5.2 Locomotor performance under sexual coercion ....................................... 1

TABLE 1

 1

	SCL F	SCL M

. Breakdown of observations (Obs) and individuals (Ind) obtained from free-ranging Hermann's tortoises of known age (289 juveniles or young adults). O-F and I-F stand respectively for observations and numbers of females, idem for males (O-M and I-M). SCL means straight carapace length (mm), both sexes pooled (SCL F+M) and separately for females and males (SCL F, SCL M). Means are provided ± their standard deviation (in brackets, σ). The proportion of tortoises that could be sexed increased with age.

Age Obs Ind O-F I-F O-M I-M SCL F+M

3 (10.2) 123.6 (3.8) 124.3 (11.2)

Age Obs Ind O-F I-F O-M I-M SCL

TABLE 2 .

 2 Model selection procedure showing all competitive models describing the variation in body condition indices (BCIs) among Hermann's tortoises from Golem Grad island and Konjsko in order of conception. r = model rank, AIC = Akaike information criteria, w = model weight, loc = locality. Shaded row denotes selected best model.

	r	Model definition	AIC	w
	3	sex	18,028.80	0.3
	4	loc	18,438.41	0.5
	2	sex+loc	17,485.90	0.2
	1	sex*loc	17,042.82	0.0

3.2.1 Fecundity and mating costs

TABLE 3 .

 3 Fecundity and body reserves data obtained from freshly dead and dissected female Hermann's tortoises from Golem Grad Island (GG) and Konjsko village (K). These individuals' BCIs in respect to their respective cohort mean BCIs can be found inFig. 10 (p. 36).

	Female K Female

GG 1 Female GG 2 Female GG 3

	3.3 SURVIVAL, POPULATION SIZE & SEX RATIO
	3.3.1 Adult survival
	Total mass	2348g	651g	914g	771g
	No. of eggs	7	0	0	0
	No. of follicles (0.5-1 cm)	35-40	0	0	0
	No. of follicles (1-2 cm)	5	2	8	0
	No. of follicles (>2 cm)	8	2	0	0
	Egg + follicle proportion	10.01%	0.97%	2.14%	0.14%
	Fat body proportion	0.30%	0.50%	0.00%	0.00%

TABLE 4

 4

	r	Model definition Survival Recapture	k	Dev.	QAIC	w
	6	cst	cst	2	12531.39 12535.39	0.3
	4	cst	het	5	12464.34 12474.34	0.2
	5	cst	sex	3	12520.16 12526.16	0.3
	3	cst	sex*het	8	12433.36 12449.36	0.2
	2	cst	sex*het*year	50	10185.95 10285.95	0.0
	1	sex	sex*het*year	51	10143.33 10245.33	0.0

. Model selection procedure showing all competitive models regarding adult Hermann's tortoise survival on Golem Grad island in order of conception. r = model rank, k = number of parameters, Dev. = deviance, QAIC = Akaike information criteria, w = model weight, loc = locality, het = heterogeneity. Shaded row denotes selected best model.

TABLE 5 .

 5 Model selection procedure showing all competitive models regarding adult Hermann's tortoise survival in Konjsko in order of conception. r = model rank, k = number of parameters, Dev. = deviance, QAIC = Akaike information criteria, w = model weight. Shaded row denotes selected best model. Despite lowering AIC, adding site and/or sex effects on discrete model survival failed to provide precise estimates, thus the age-effect discrete model was used for comparison purposes. With covariates, best model fit was achieved when

	r	Model definition Survival Recapture	k	Dev.	QAIC	w
	3	cst	cst	2	2259.6	2263.6	0.3
	4	cst	het	5	2253.6	2263.6	0.3
	5	cst	sex	3	2259.4	2265.4	0.3
	2	cst	year	8	1833.1	1949.1	0.0
	1	sex	year	9	1928.6	1946.6	0.0
						56 and 0.71, the low
	recapture class from 0.01 to 0.07 and Beach tortoises somewhere in the middle
	between 0.32 and 0.40. All recapture probabilities express additive time variation.
	Exploring different parameterizations of the age-effect on survival resulted with
	a logarithmic to linear relationship reaching a plateau at five to seven years of

3.3.2 Early-life age-specific survival

The goodness-of-fit tests were significant (chi2=127.35 and 72.09, df=60 and 31, respectively, p<0.001) with significant transience and trap-dependence (both p<0.001), suggesting strong survival or recapture heterogeneity.

After model selection, regarding recapture probability two to six-year olds formed a separate cohort whereas all further age classes up to ten-year olds were considered separately. All are site dependent, while only those from the Plateau experience recapture heterogeneity (lowering AIC by 71). Among them, the class with higher recapture probabilities ranged between 0.age, or a discrete model summiting at the age of five (ΔAIC between these models ranged between 0.6 and 1.3, Table

6

; models whose ΔAIC from the best fit model <2 are considered to also have substantial support

[Burnham & Anderson 2002]

).

TABLE 6 .

 6 Model

	r	Survival	Model definition	Recapture	k	Dev.	AIC	w
	Age		age		33	4360,2 4426,2 0,0
	Age		age*year		155 3966,0 4276,0 0,0
	Age		age+year		48	4015,5 4111,5 0,0
	Age		[age1;2-10]+year	32	4510,6 4574,6 0,0
	Age		[age1;2;3-10]+year	34	4473,1 4541,1 0,0
	Age		[age1;2-3;4-10]+year	34	4412,3 4480,3 0,0
	Age		[age1;2-4;5-10]+year	34	4345,2 4413,2 0,0
	Age		[age1;2-5;6-10]+year	34	4290,1 4358,1 0,0
	Age		[age1;2-6;7-10]+year	34	4227,1 4295,1 0,0
	Age		[age1;2-7;8-10]+year	34	4160,3 4228,3 0,0
	Age		[age1;2-8;9-10]+year	34	4156,8 4224,8 0,0
	Age		[age1;2-9;10]+year	34	4193,6 4261,6 0,0
	Age		[age1;2-4;5;6;7;8;9;10]+year	46	4019,2 4111,2 0,0
	Age		[age1;2-3;4-6;7-10]+year	36	4223,0 4295,0 0,0
	Age		[age1;2;3;4;5-10]+year	38	4341,2 4417,2 0,0

selection procedure showing all competing models for 1-10-year-old Hermann's tortoises from Golem Grad in order of conception: r = model rank; k = number of parameters; Dev. = residual deviance; AICc = Akaike information criteria; w = AICc relative weight; age = discrete model; H = capture heterogeneity; P = Plateau; Lin, Quad, Log = linear, quadratic, logarithmic covariate, respectively, on the age-survival relationship, _ = survival plateau.

3.3.3 Population sizes & age-specific sex ratios

According to estimates, Konjsko holds a larger population of adult Hermann's tortoises than Golem Grad by 1,230 individuals. Nonetheless, males were more numerous on Golem Grad

(1,737.60 [SD=15.94]

vs.

1,211.76 [SD=89.51]

), unlike the females that in comparison are barely present on the island

(159.45 [SD=7.8]

TABLE 7

 7

. Estimated age -specific sex ratios of Hermann's tortoises from Golem Grad island before maturity. 95% CIs are given in parentheses.

TABLE 8

 8

	Model		np	Deviance	QAIC	DQAIC
	Modelling re-sighting probability
	S(sex*site) y(sex*site*state) p(sex*site*state*t)	1	90	10220.4	10400.4	43.2
	S(sex*site) y(sex*site*state) p(sex*site*state)	2	34	11092.4	11160.4	803.2
	S(sex*site) y(sex*site*state) p(sex*state*t)	3	58	10257.3	10373.3	16.1
	S(sex*site) y (sex*site*state) p(state*t)	4	40	10277.2	10357.2	0
	S(sex*site) y(sex*site*state) p(t)	5	28	10391.5	10447.5	90.3
	Modelling survival probability
	S(sex) y(sex*site*state) p(state*t)	6	38	10218.3	10357.3	0.1
	S(.) y(sex*site*state) p(state*t)	7	37	10305.2	10379.2	22
	Modelling transition probability
	S(sex*site) y(sex*state) p(state*t)	8	34	10290.1	10358.1	0.9
	S(sex*site) y(site*state) p(state*t)	9	37	10284.9	10358.9	1.7

. Multistate mark-recapture (MSMR) analyses of male tortoise behaviours. Modelling probabilities of survival (S), re-sighting (p) and of transition between behavioural states (y) of Hermann's tortoises on Golem Grad, 2008-2014. Abbreviations: np, number of parameters; AIC, Akaike Information Criterion; sex, sex dependence; site, site dependence; state, state dependence; t, time dependence; "*", interaction; "." constant parameter. The selected model is indicated in bold. The initial model (model 1) fitted to the data (χ²105 = 110.2, P=0.345).

TABLE 9

 9

	Source	S Sq	Df	M Sq	F	P
	Intercept	7.394E+13 1 7.394E+13 1276.120 <0.001
	Population (P)	4.628E+12 1 4.628E+12 79.884 <0.001
	Injury level (IL)	1.208E+12 4 3.019E+11 5.211 <0.001
	Interaction (IL*P)	1.632E+11 4 4.081E+10 0.704	0.590
	Error	1.147E+13 198 5.794E+10

. Statistics from the ANOVA to compare the mean body size (SCL, Box-Cox transformed data) between populations (P: Konjsko vs. Golem Grad) and among three injury levels; in total, N = 208 individual females were used

TABLE 10 .

 10 Population and cohort (sex) mean estimates of growth parameters obtained via growth models (Bertalanffy and logistic) built on the known age and unknown age datasets of Hermann's tortoises from Golem Grad island. Sample size is indicated (n). F, M, k, SCLA, SCL0 and R 2 denote female, male, growth rate, asymptotic SCL (mean±SE), SCL at birth and coefficient of determination, respectively. Analytically obtained SCL0 values are denoted with an asterisk (*). FIGURE 9. Estimated individual growth trajectories of three pairs of adult Hermann's tortoises of unknown age from Golem Grad Island with similar straight carapace lengths at the time of first capture, monitored during at least five consecutive years. Each pair is indicated with a colour pattern (black, light and dark grey) and with two line types (solid vs. dashed)

	Source	n	k	SCL A	SCL 0 R 2
	Unknown age	2,034 0.0003 180.7±0.9 34.6* 2.23
	Unknown age F	123 0.0005 188.7 ±3.2 38.7* 2.36
	Unknown age M	1,911 0.0003 179.9 ±1.0 33.9* 2.20
	Known age, logistic	1,072 0.001 175.3±2.7 32.8 7.24
	Known age, logistic F	107	0.001 178.1±8.0 29.2 8.92
	Known age, logistic M	423	0.001 172.4±4.6 34.0 7.61
	Known age, Bertalanffy 1,072 0.0001 511.8±75.5 25.9 7.45
	1

  have made that combination of life-history traits a

	chelonian Achilles' heel, with almost 70% of all 335 species threatened or recently
	extinct (almost 46% of which endangered or critically endangered); for many,
	conservation status has not been assessed (van Dijk et al. 2014). In order to
	counter this trend robust age-specific survival estimates are necessary to provide
	age-specific survival elasticities. Indeed, developing reliable projections of
	population growth using matrix models (Caswell H. 2001), evaluating
	conservation priorities (Congdon et al. 1993; Heppel 1998; Enneson & Litzgus
	2008) and estimating conservation efficiency (e.g. after reintroduction and/or
	head-starting in Heppel et al. 1996a; Mitrus 2005; Canessa et al. 2016) rely on such
	endeavours in long-lived animals.

Alas, the elusive nature of chelonian early life precludes the amassing of large and dense CR (Capture-Recapture) datasets of aged immature turtles, actively hindering this goal. Although chelonian adult survival is relatively wellstudied

[START_REF] Congdon | Demographics of Common Snapping Turtles (Chelydra serpentina): Implications for Conservation and Management of Long-Lived Organisms[END_REF][START_REF] Henry | Survival rates and demography of the Hermann's tortoise Testudo hermanni in Corsica, France[END_REF][START_REF] Chaloupka | Estimates of sex-and age-class-specific survival probabilities for a southern Great Barrier Reef green sea turtle population[END_REF][START_REF] Olivier | Assessing spatial and temporal population dynamics of cryptic species: an example with the European pond turtle[END_REF][START_REF] Bertolero | Testudo hermanni (Gmelin 1789) -Hermann's Tortoise[END_REF][START_REF] Bertolero | The importance of including survival release costs when assessing viability in reptile translocations[END_REF]

, sporadic insight on early survival fails to paint a clear picture. Indeed, a rapid review of the sparse literature on age-specific early life chelonian survival revealed a wide spectrum of estimates ranging from 11% in neonate European pond turtles to 92% in juvenile Loggerhead turtles (Table

TABLE 11 .

 11 Review of published chelonian age-or stage-specific survival estimates prior to maturity. Some studies reported ambiguous age categories here presented as immature. When explicitly reported, materials and methods are also provided.

	Species	Immature (age-specific) survival	Materials & Methods	Reference
		Land Tortoises
		Neonate: 0.39 +/-0.10
		1-year-old: 0.45 +/-0.08
	T. h. hermanni	2-year-old: 0.77 +/-0.08 3-year-old: 0.68 +/-0.07	19 years of CR, Cormack-Jolly-Seber (CJS) model	Fernández-Chacón et al. 2011
		4-year-old: 0.86 +/-0.06
		5-year-old: 0.88 +/-0.05
	T. h. hermanni	Neonate: 0.54 1-2 years-old: 0.64 3-9 years-old: 0.91	14 years of CR, CJS model	Bertolero 2002
	T. h. hermanni	0-2 years-old: 0.52 3-9 years-old: 0.88	7 years of CR	Henry et al. 1999
	Testudo graeca	Neonate: 0.39	Thread trailing	Keller et al. 1998
	Gopherus polyphemus	1-4 years-old: 0.45	/	Wilson, 1991
	Gopherus polyphemus	Immature: 0.84 +/-0.05	12 years of CR, CJS open population model	Tuberville et al. 2008
		Freshwater Turtles
		neonate: 0.02-0.08
		1 year-old: 0.53
	Emys orbicularis	2 years-old: 0.80 3-6 years-old: 0.45-0.99	7 years of CR, CJS model	Canessa et al. 2016
		7-11 years-old: 0.55-1.15
		12+ years old: 0.68-1.69
	Emys orbicularis	neonate: 0.11 1-year-old: 0.64	3 years of CR	Mitrus 2005
	Emys orbicularis	1-year-old: 0.53	/	Mitrus 2002

By means of advanced multievent CR modelling, this study demonstrates that even sparse datasets can be used to obtain age-specific estimates of survival in long-lived species. Consequently, it demonstrates that, as in other long-lived vertebrates, the substantially prolonged immature phase of the Hermann's tortoise and the European pond turtle entail a steep and progressive increase in survival with age. The age-linear covariate (continuous) models are streamlined versions of their discrete counterparts, suggesting no bias in the age-specific survival estimates. Moreover, the continuous models clearly outperformed the discrete models in terms of precision, especially in the sparser dataset of the European pond turtle (Fig.

14

). FIGURE 14. Estimated age-specific mean survival probabilities and 95% CIs of young European pond turtles from Camargue, France obtained from a discrete model (Model rank 7, Table 5 in Arsovski et al. 2018), superimposed against the estimates and 95% confidence spread of mean age-specific survival probabilities of the same population obtained from the best-fit covariate model (Model rank 1, Table 5 in Arsovski et al. 2018).

Most notably, the discrete models failed to estimate neonate survival due to the lack of marked neonates. The continuous models partially solve this issue by projecting the linear relationship of age and survival on neonate survival.

Nevertheless, such predictions bear considerable uncertainty and should only be considered surrogates until they can be supported by proper data collected on this age class. Due to the difficulty of capturing and recapturing elusive immature reptiles, researchers have often opted for indirect estimates of juvenile survival, such as catch-curve analyses (Table

11

), or indirect mathematical approaches

[START_REF] Pike | Estimating survival rates of uncatchable animals: the myth of high juvenile mortality in reptiles[END_REF]

. The only robust study comes from a reintroduction Furthermore, several other long-lived vertebrates also exhibit a linear increase in age-specific survival (see for instance

[START_REF] Delong | Age-and sex-specific survival of California sea lions (Zalophus californianus) at San Miguel Island, California[END_REF][START_REF] Forslund | Age and reproduction in birds -hypotheses and tests[END_REF]

  from a wide array of lineages inSommer and Vasey 2006;[START_REF] Bailey | Same-sex sexual behavior and evolution[END_REF]

	Poiani 2010; Scharf and Martin 2013) have attracted generous research,
	particularly ultimate causes. Yet, there is a disbalance, little attention has been
	paid to nonadaptive hypotheses (Scharf and Martin 2013; for adaptive

hypotheses see

[START_REF] Camperio-Ciani | Evidence for maternally inherited factors favouring male homosexuality and promoting female fecundity[END_REF][START_REF] Macfarlane | Same-sex sexual behavior in birds: expression is related to social mating system and state of development at hatching[END_REF][START_REF] Bailey | Same-sex sexual behavior and evolution[END_REF][START_REF] Bierbach | Homosexual behaviour increases male attractiveness to females[END_REF][START_REF] Vanderlaan | The "female fertility-social stratification-hypergyny" hypothesis of male homosexual preference: factual, conceptual and methodological errors in Barthes et al. [Commentary[END_REF]

. Proximate causes, on the other hand, are likely technically difficult to investigate since SSB is often intermingled with other sexual behaviours, such as heterosexual behaviours (HSB) making it difficult to tease them apart and exclusively correlate SSB with physiological or genetic factors (for a rare example on snakes see

[START_REF] Shine | The transvestite serpent: why do male garter snakes court (some) other males?[END_REF]

. It is nevertheless known that physiological factors (e.g. hormones) influence behaviours

[START_REF] Nelson | An introduction to behavioral endocrinology[END_REF][START_REF] Goldey | Sexual Modulation of Testosterone: Insights for Humans from Across Species[END_REF]

and by extension should likely influence SSB. Endocrinological experimental studies so far have explored sexual orientation through sex steroids

[START_REF] Poiani | Animal homosexuality: a biosocial perspective[END_REF][START_REF] Goldey | Sexual Modulation of Testosterone: Insights for Humans from Across Species[END_REF]

TABLE 12 .

 12 Population density (number of individuals per hectare, D), numbers of adults sampled (N), and sex ratio (SR, adult males/ adult females) among 16 populations/sub-populations of T. h. boettgeri monitored in Greece (data from the Tables2 and 3in[START_REF] Hailey | Population density and adult sex ratio of the tortoise Testudo hermanni in Greece: evidence for intrinsic population regulation[END_REF] and in Macedonia (Golem Grad, Konjsko) and in three other species of Testudo (T.h.h., JMB, unpublished; T. horsfieldii,[START_REF] Bonnet | Sexual dimorphism in steppe tortoises (Testudo horsfieldii): Influence of the environment and sexual selection on body shape and mobility[END_REF][START_REF] Lagarde | A short spring before a long jump: the ecological challenge to the steppe tortoise (Testudo horsfieldi)[END_REF] T. graeca, Lagarde et al. 2008; XB, unpublished). SSB stands for same sex sexual behaviours that were observed in males only (expressed as % relative to all sexual behaviours recorded). The last column indicates the number of heterosexual behaviours (HSB) observed. Populations were ranked according to increasing density.

	Species	Site	D	N	SR	SSB % HSB
	T h. hermanni	Callas	1.2	258	0.93	0	27
	T h. hermanni	Saint Daumas	1.2	123	0.84	0	71
	T h. hermanni	Lambert	1.6	64	1.21	0	4
	T. h. boettgeri	Deskati	3.7	201	4.02	0	-
	T h. hermanni	Redon	4.2	105	1.55	0	29

TABLE 13 .

 13 Basic characteristics of the five study sites of chapter 7 including: approximate surveyed area (ha), degree of urbanization, site protection status, identified (observed and/or reported) threats; crude survey effort.

	Study site	Trstenik	Danilovgrad	Golem Grad Island Pčinja River valley	Konjsko village
	Approximate surveyed surface (ha)	25	4.3	20	25	15
	Urbanization	Villages and weekend houses, arable land	Surrounded by motorway, arable land and settlement	Uninhabited, tourists	Weekend houses, gardens	Uninhabited village, tourists
	Site protection status	None: sub-urban area	None: sub-urban area	Strictly protected Park area of a National	Landscape of Features Outstanding	National Park
	Threats	Illegal collection, agriculture, vehicle collisions	Wildfires, vehicle collisions, urbanization	Closed population, female mortality male-biased sex ratio, increased	None recorded	None recorded
	Search effort (person-days)	17 days, 2-4 people (51); 2009, 2011 and 2012	48 days, 1-5 people (144); 2010-2012	133 days, 4-17 people (1,330); 2008-2013	26 days, 4-10 people (182); 2008, 2009 and 2012	22 days, 4-8 people (132); 2010-2012

[START_REF] Bertolero | The importance of including survival release costs when assessing viability in reptile translocations[END_REF]

. Besides Hermann's tortoises, this practice could likely benefit all other Testudo species, and probably also other animals with coercive mating rituals and a long life. As a species with temperature-dependent sex determination, the Hermann's tortoise is a convenient candidate for the successful and efficient implementation of such conservation advice via captive breeding programs. On another note, if harvest programs are impossible to ban in certain countries (legal in Serbia), they should at least be heavily controlled. Males should be the most exploited sex, but if possible, adults should altogether be avoided in such long-lived species.

Extracting knowledge from such examples can provide simpler conservation advices that are easy to follow, and offer more efficient resource spending, making conservation cheaper. Yet conservation today is neither cheap nor efficient.

  1 -not observed, 2 -observed as an adult living individual; this event masks both high and low recapture probabilities (p A+ and p A-, respectively), and probability to be recovered as a dead tortoise shell

(p RS ). From an initial model: Ф [sex*site], P [sex*site*het*t], we used a backwards selection procedure, retaining the best linear combination [lowest Akaike information criterion (AIC, Burnham & Anderson 2002)] first on recapture probability and then survival.

TABLE 1A

 1A

	matrix Ф	matrix P

. Elementary matrices: Ф (survival) estimating transition probabilities from t to t + 1 i.e. survival probabilities (ф). Once an individual's carapace has been recovered, during the following transition it can only transit into the unobservable dead state ( †). Elementary matrix P estimating recapture probabilities: observed as an adult with high capture probability (p A+ ), observed as an adult with low capture probability (p A+ ), observed as a recovered carapace (p DR ).

TABLE 6A .

 6A Behaviours (resightings of 1,737 individuals, 2008Behaviours (resightings of 1,737 individuals, -2014) ) were classified into 3 main categories: inactive, active, or sexual; (A) and (P) mean, respectively, sexually active versus sexually passive. Sample size (N) indicates the total number of observations; for example, 15 pairs of fighting males involve 30 individuals (some information was missing). SSB (%) indicates the actual number and proportion of SSBs observed; these involved only males (except for one female mounting another female).

	Behaviour	Definition	Category	N	SSB (%)
	Burrowed	Partly burrowed, head and legs retracted	Inactive	677
	In the shade	Motionless in the shade	Inactive	2513
	Basking	Fully exposed to sunrays, legs deployed	Active	1729
	Foraging	Eating plant, fungi, or animals	Active	195
	Hiding	In shelter (bush, undergrowth, etc.)	Active	718
	Walking	Walking alone	Active	755
	Chased	Trying to escape from a sexual assault of a male	Sexual (P)	30	25 (83)
	Chasing	Male pursuing a conspecific	Sexual (A)	31	25 (81)
	Courted	Courted by a mail	Sexual (P)	22	10 (45)
	Courting	Male courting a conspecific, mounting attempts	Sexual (A)	22	10 (45)
	Fighting	Male to male combat, violent shell shocks, and bites	Sexual (A)	30	0 (0)
	Sex group	Sexually active group, e.g. 2-5males courting a female Sexual	101	36 (36)
	Mounting	Male mounting any conspecific, vocalizing,	Sexual (A)	667	506 (76)
		ejaculation
	Necrophilia	Male mounting a dead tortoise, vocalizing	Sexual (A)	5	5 (100)
	Skeletophilia Male mounting an empty carapace, vocalizing	Sexual (A)	5	5 (100)
	Sex train	Several males forming a line while pursuing a female	Sexual	3	0 (0)
	Not	Missing information, ambiguous behavior, dead		2075
	classified	individual

ACKNOWLEDGMENTS

assume that the ratio of the sexes (the ratio of reproductively active males to active females in a given population at a given time -OSR [START_REF] Emlen | Ecology, sexual selection, and the evolution of mating systems[END_REF]) could govern the asymmetries in the costs and benefits of mating i.e. has a profound impact on sexual selection [START_REF] Kvarnemo | The dynamics of operational sex ratios and competition for mates[END_REF][START_REF] Parker | Sexual selection and sexual conflict[END_REF].

Namely, when the ratio of the sexes in conflict is biased in favour of the sex with higher optimal mating rates, the other sex experiences additional costs [START_REF] Fitze | Operational sex ratio, sexual conflict and the intensity of sexual selection[END_REF][START_REF] Galliard | Sex ratio bias, male aggression, and population collapse in lizards[END_REF]. Most literature on sexual conflict suggests that such bias should then be buffered with a control mechanism i.e. the sex in excess should experience higher selection pressure via intrasexual competition [START_REF] Greenwood | Mating Systems, Philopatry and Dispersal in Birds and Mammals[END_REF][START_REF] Wolff | Effects of adult sex ratios on recruitment of juvenile gray-tailed voles, Microtus canicaudus[END_REF].

Recently, researchers have paid attention to the complex interactions between OSR, mating and breeding costs, that can drive sexual selection in previously unexpected directions [START_REF] Fitze | Operational sex ratio, sexual conflict and the intensity of sexual selection[END_REF][START_REF] Kokko | Why is mutual mate choice not the norm? Operational sex ratios, sex roles and the evolution of sexually dimorphic and monomorphic signalling[END_REF][START_REF] Kokko | Predicting the direction of sexual selection[END_REF]. This rings particularly true for sexually coercive mating systems where OSR bias can fuel sexual conflict by furthering the intersexual gap in optimal mating rates. For example, coercion can directly impact fitness through physical damage [e.g. to genitalia in garter snakes [START_REF] Friesen | Sexual conflict over mating in red-sided garter snakes (Thamnophis sirtalis) as indicated by experimental manipulation of genitalia[END_REF], genital area in mosquito fish [START_REF] Wang | Coevolution of male courtship and sexual conflict characters in mosquitofish[END_REF], cloacae in Hermann's tortoises (results; Hailey 1990), general wounding in some non-human primates [START_REF] Smuts | Male Aggression and Sexual Coercion of Females in Nonhuman Primates and Other Mammals: Evidence and Theoretical Implications[END_REF]], but also indirectly via the reduction of foraging rate [START_REF] Magurran | A Cost of Sexual Harassment in the Guppy, Poecilia reticulata[END_REF][START_REF] Rowe | The costs of mating and mate choice in water striders[END_REF][START_REF] Rubenstein | Ecology and sociality in horses and zebras[END_REF][START_REF] Stone | Female foraging responses to sexual harassment in the solitary bee Anthophora plumipes[END_REF], or even longevity of the harassed sex [START_REF] Clutton-Brock | Persistent courtship reduces male and female longevity in captive tsetse flies Glossina morsitans morsitans Westwood (Diptera: Glossinidae)[END_REF][START_REF] Rowe | The costs of mating and mate choice in water striders[END_REF][START_REF] Smuts | Male Aggression and Sexual Coercion of Females in Nonhuman Primates and Other Mammals: Evidence and Theoretical Implications[END_REF][START_REF] Westneat | The ecology and evolution of extra-pair copulations in birds[END_REF]). Thus, while increasing sexual harassment promotes mating success, it can increase mating costs to the extent of preventing the harassed sex from reproducing at all, generating substantial costs to both sexes (Clutton-Brock & Langley 1997). Coincidentally, [START_REF] Smuts | Male Aggression and Sexual Coercion of Females in Nonhuman Primates and Other Mammals: Evidence and Theoretical Implications[END_REF] proposed sexual coercion as a third form of sexual selection [alongside intrasexual competition and mate choice [START_REF] Darwin | The descent of man and selection in relation to sex[END_REF]]. Empirical studies on coercive mating systems have demonstrated how the force of sexual selection can be steered away from the prevalent sex by the interaction of (coercive) mating and breeding costs with OSR bias. For instance, Le Gaillard et al. (2005) as well as Fitze & Le Gaillard (2008) manipulated the OSRs of experimental viviparous 'AICcmodavg' package [START_REF] Mazerolle | AICcmodavg: Model selection and multimodel inference based on (Q)AIC(c)[END_REF] and plotted in R v0.99.879 (R Core Team 2014).

Fecundity and mating costs

Recently dead individuals found in the field were carefully dissected.

Female fecundity was noted by counting eggs in the oviducts and ovarian follicles of different sizes (0.5-1cm, 1-2cm and >2cm in diameter) in the ovaria.

Taking into account the difficulty of estimating tortoise fecundity in lack of appropriate equipment (e.g. x-ray machine) and nest site location, this method provides precise data but very small not random sample sizes (no animals were sacrificed; Golem Grad N[♀]=3, Konjsko N[♀]=1) despite the long period of study.

The proportions of both body fat and entire reproductive system (oviducts + ovaria + follicles and eggs) from total body mass were calculated for each individual.

SURVIVAL, POPULATION SIZE & SEX RATIO

Primarily goodness-of-fit tests were performed on the datasets based on the CJS model using U-CARE (Choquet et al. 2009a). All following survival analyses were performed in E-SURGE (Choquet et al. 2009b). The obtained capture probabilities from the best fit models, along with the raw numbers of individuals could be used to estimate population size, and/or cohort sizes (sex, age, sexual behavior etc.). Sex-specific population sizes were used to estimate sex-ratio among age classes as well as OSR. Parametric bootstrapping was used

Adult survival

Adult survival was estimated using CR histories of adult individuals [START_REF] Bertolero | Testudo hermanni (Gmelin 1789) -Hermann's Tortoise[END_REF] from Konjsko (complete CR dataset) and Golem Grad (1,309 individuals; 4,415 annual recaptures), separately, collected by 2017 and 2016, respectively. Multievent [START_REF] Pradel | Multievent: An extension of multistate capture-recapture models to uncertain states[END_REF]) mixture models [START_REF] Pledger | Open Capture-Recapture Models with Heterogeneity: I. Cormack-Jolly-Seber Model[END_REF] combining live recaptures and dead recoveries [START_REF] Schaub | Assessing the relative importance of different sources of mortality from recoveries of marked animals[END_REF] were implemented in the software E-SURGE (Choquet et al. 2009b). Mixture models allow for recapture heterogeneity (by masking multiple heterogeneity states

Early-life age-specific survival

The following analyses were performed on field data collected between 2008 and 2016;

during 19 field sessions adding up to 169 days, 1,225 recaptures were collected from 466 aged immature individuals (<130mm SCL). All of the individuals used in these analyses are present in the known-age growth dataset (pp. 16., Table 1); more individuals could be added to the survival analyses even if they hadn't been recaptured twice or more after using the growth model to ascertain their ages-at-capture via individual SCLs. All used tortoises were born between 1,999 and 2015; the chronological breakdown of captured animal numbers per birth year can be found in Table 2A. Heterogeneity and sex uncertainty were dealt with using multievent model approaches [START_REF] Pledger | Open Capture-Recapture Models with Heterogeneity: I. Cormack-Jolly-Seber Model[END_REF][START_REF] Pradel | Multievent: An extension of multistate capture-recapture models to uncertain states[END_REF], thus sex was also coded as state, instead of group (as was in the adult survival dataset). The models were based on 9 underlying biological states denoting differences in sex, site and heterogeneity class (Table 3A). Lastly, different parametrizations of the age effect on survival probabilities, namely linear, logarithmic and quadratic versus discrete were investigated, as well as different ages at plateau. The results from the best-fit discrete model were superimposed against those aided by covariates and possible benefits and drawbacks were noted.

Population sizes and age-specific sex ratios

Population sizes and OSRs with 95% confidence intervals (CIs) were obtained using parametric bootstrapping (10,000 bootstraps) based on the variance-covariance matrices of model estimates and implemented in R v0.99.879 (R Core Team 2014) using the packages 'MASS' [START_REF] Venables | Modern Applied Statistics With S[END_REF], 'boot' [START_REF] Canty | boot: Bootstrap R (S-Plus) functions[END_REF] and 'popbio' [START_REF] Stubben | Estimating and analyzing demographic models[END_REF]. Precisely, raw numbers of captured adult females and males of both localities were divided by their respective capture probabilities. Due to sex uncertainty at first capture and age-specificity, populations sizes of neonate-to-nine-year-olds were estimated using an additional variable -initial state probabilities of being a given sex multiplied by the raw numbers of captured individuals, averaged between years of capture, which were then divided by the respective capture probabilities.

Finally, age-specific OSRs were calculated (N[♂]/N[♀]).

Survival temporal variance & canalization

Gould & Nichols (1998) introduced a method for the estimation of the true temporal variance of a given trait by removing the sampling variance from the total variance. This approach was used to calculate the standard deviations of mean sex-specific annual adult survival in Hermann's tortoises from Golem Grad Island. A sex-specific time dependent survival model was used to extract annual survival probabilities and their respective variance-covariance matrices. Due to a lack of replicate populations, and in order to provide uncertainty measures to variance estimates, the original CR-histories were bootstrapped and mean annual survival temporal variances extracted for each bootstrap. Since E-SURGE does not offer this option automatically, the sample was limited to 50 manually obtained bootstraps. The variance of variances was subsequently obtained, providing CIs.

Population projections

Estimated demographic parameters from the best-fitted models of adult and early-life age-specific survival (see results) of Hermann's tortoises on Golem Grad Island were integrated in a deterministic pre-breeding population matrix model with 10 age classes and both sexes (Caswell 2001). Since our results implied a survival plateau at five years of age and no sex-specificity, five-to nineyear olds received the at-plateau survival estimate, no estimates differing between the sexes up to nine years of age; 10-year-olds received the respective adult sex-specific values. In another run, we applied an even worse case scenario where female tortoises received lower survival values from the age of eight, since our results implied that on Golem Grad females likely become a target to male sexual coercion around that age and females from the Island Plateau do indeed express lower survival values (see results). In the attempt to evaluate whether adult survival could explain present Golem Grad OSR, initial OSR was considered to be one, fecundity we set to the average value provided for the species (4.3) and reproduction was allowed from the age of eight [START_REF] Bertolero | Testudo hermanni (Gmelin 1789) -Hermann's Tortoise[END_REF]. Additionally, in order to see the effect of sex differences in survival on annual population growth rate, we performed the same analyses without sexspecific survival (using the male estimates).