Andreas Ravache
email: andreas.ravache@ird.fr

Karen Bourgeois

Sylvain Dromzée

Henri Weimerskirch

Sophie De Grissac

Aurélien Prudor

Anne Lorrain

Martin Thibault

Christophe Menkès

Valérie Allain

Christophe Menkes

Paco Bustamante

Yves Letourneur

Éric Vidal

Flying to the moon: Lunar cycle influences trip duration and nocturnal foraging behavior of the wedge-tailed shearwater Ardenna pacifica

Keywords: Ardenna pacifica, Foraging, Lunar Phase, Moon, GPS-tracking, Stable isotope analyses

ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Introduction

Lunar cycle is known to influence the behavior and physiology of a wide range of living organisms, as well as predator-prey relationships [START_REF] Grant | Amphibians' response to the lunar synodic cycle-a review of current knowledge, recommendations, and implications for conservation[END_REF][START_REF] Prugh | Does moonlight increase predation risk? Meta-analysis reveals divergent responses of nocturnal mammals to lunar cycles[END_REF][START_REF] Zimecki | The lunar cycle: effects on human and animal behavior and physiology[END_REF]. Predators relying on visual cues to find their prey can increase their foraging activity at night during higher moonlight intensity, while prey can decrease their activity under such conditions [START_REF] Martin | Birds by Night[END_REF][START_REF] Prugh | Does moonlight increase predation risk? Meta-analysis reveals divergent responses of nocturnal mammals to lunar cycles[END_REF]. Of marine taxa, Procellariid seabirds return to their colonies after dark, and adapt at-sea foraging trips to attend the colony under moonless conditions, are most likely to be affected by the lunar cycle. [START_REF] Brooke | Albatrosses and Petrels across the World[END_REF][START_REF] Mougeot | Predation risk and moonlight avoidance in nocturnal seabirds[END_REF]. To date, this avoidance of the colony under moonlight has most commonly been interpreted as an antipredator adaptation. Indeed, moonlight avoidance is related to predation rate in nocturnal Procellariids [START_REF] Keitt | Nocturnal behavior reduces predation pressure on Blackvented Shearwaters Puffinus opisthomelas[END_REF][START_REF] Watanuki | Moonlight avoidance behavior in Leach's storm-petrels (Oceanodroma leucorhoa) as a defense against Slaty-backed gulls[END_REF]. Even in predator-free locations, moonlight avoidance has been observed in some populations, allegedly due to an innate and persistent behavior inherited from co-evolution with predators [START_REF] Bretagnolle | Audubon's shearwaters Puffinus lherminieri on Reunion Island, Indian Ocean: behaviour, census, distribution, biometrics and breeding biology[END_REF].

However, reduced activity at the colony during moonlit nights may also be a result of increased activity elsewhere, such as nocturnal at-sea foraging. Procellariiform species, which are visual predators lacking night vision adaptations [START_REF] Brooke | Albatrosses and Petrels across the World[END_REF], should, therefore, benefit from moonlight, that would allow improved nocturnal foraging. Several studies have shown that shearwater, petrel and albatross nocturnal at sea activity was enhanced during full moon nights compared with moonless nights, both during the breeding [START_REF] Dias | Distribution and at-sea activity of a nocturnal seabird, the Bulwer's petrel Bulweria bulwerii, during the incubation period[END_REF][START_REF] Phalan | Foraging behaviour of four albatross species by night and day[END_REF][START_REF] Rubolini | The Effect of Moonlight on Scopoli's Shearwater Calonectris diomedea Colony Attendance Patterns and Nocturnal Foraging: A Test of the Foraging Efficiency Hypothesis[END_REF] and non-breeding periods [START_REF] Dias | the day or the night shift? Foraging schedules of Cory's shearwaters vary according to marine habitat[END_REF][START_REF] Pinet | Celestial moderation of tropical seabird behavior[END_REF][START_REF] Yamamoto | The lunar cycle affects at-sea behaviour in a pelagic seabird, the streaked shearwater, Calonectris leucomelas[END_REF]. The hypothesis of nocturnal foraging is also supported by increased availability of some seabird prey in subsurface waters during night time thanks to the Diel Vertical Migration (DVM) which is the vertical migration of micronekton, the prey species of many predators, toward the surface at night and in deeper waters during the day [START_REF] Hays | A review of the adaptive significance and ecosystem consequences of zooplankton diel vertical migrations[END_REF][START_REF] Brooke | Albatrosses and Petrels across the World[END_REF]. Prey availability at the surface changes along with variations in the DVM, being reduced on full moon nights and higher during new moon nights [START_REF] Benoit-Bird | Nocturnal light and lunar cycle effects on diel migration of micronekton[END_REF][START_REF] Gliwicz | A lunar cycle in Zooplankton[END_REF]. However, [START_REF] Waap | The diet of a nocturnal pelagic predator, the Bulwer's petrel, across the lunar cycle[END_REF] found no evidence of dietary shift in prey species composition or diversity according to the lunar cycle in nocturnally foraging and shallow-diving Procellariid species, the Bulwer's petrel, which feeds on mesopelagic species brought close to the surface during DVM. Furthermore, research conducted on the same species revealed a relatively weak effect of lunar phase on its activity (10% more time flying during full moon compared to other lunar phase; [START_REF] Dias | Distribution and at-sea activity of a nocturnal seabird, the Bulwer's petrel Bulweria bulwerii, during the incubation period[END_REF]. Combined, these results suggest that normally deep prey are available at the surface in sufficient amounts to be accessed by seabirds, even during full moon nights. Some Procellariid species, for example wedge-tailed shearwaters (Ardenna pacifica Gmelin, 1789), are thought to primarily forage during daylight [START_REF] Catry | Movements, at-sea distribution and behaviour of a tropical pelagic seabird: The wedge-tailed shearwater in the western Indian Ocean[END_REF], and often in association with subsurface predators such as tuna [START_REF] Au | Seabird interactions with dolphins and tuna in the eastern tropical Pacific[END_REF][START_REF] Hebshi | Associations between seabirds and subsurface predators around Oahu, Hawaii[END_REF][START_REF] Miller | Importance of tropical tuna for seabird foraging over a marine productivity gradient[END_REF][START_REF] Spear | Foraging dynamics of seabirds in the eastern tropical Pacific Ocean[END_REF]. Epipelagic tuna are generally considered to be diurnal foragers [START_REF] Roger | Relationships among yellowfin and skipjack tuna, their prey-fish and plankton[END_REF], although some studies demonstrate occasional nocturnal foraging [START_REF] Schaefer | Vertical Movements and Habitat Utilization of Skipjack (Katsuwonus pelamis), Yellowfin (Thunnus albacares), and Bigeye (Thunnus obesus) Tunas in the Equatorial Eastern Pacific Ocean, Ascertained Through Archival Tag Data[END_REF]. These associations, by which surface predators drive prey close to the surface [START_REF] Ashmole | Seabird ecology and the marine environment[END_REF], facilitate foraging [START_REF] Hebshi | Associations between seabirds and subsurface predators around Oahu, Hawaii[END_REF][START_REF] Miller | Importance of tropical tuna for seabird foraging over a marine productivity gradient[END_REF] for shallow-diving procellariids like wedge-tailed shearwaters (mean maximum diving depth: 5-14 m; [START_REF] Burger | Diving Depths of Shearwaters[END_REF][START_REF] Peck | Colony-specific foraging behaviour and co-ordinated divergence of chick development in the wedge-tailed shearwater Puffinus pacificus[END_REF]. This is particularly true in oligotrophic tropical waters where wedge-tailed shearwaters have been documented foraging in association with yellowfin (Thunnus albacares) and skipjack (Katsuwonus pelamis) tuna [START_REF] Miller | Importance of tropical tuna for seabird foraging over a marine productivity gradient[END_REF].

However, wedge-tailed shearwaters have also been documented foraging during full moon nights [START_REF] Gould | Nocturnal Feeding of Sterna fuscata and Puffinus pacificus[END_REF] which suggests that other factors than sub-surface predator associations, for instance the lunar phase or prey migration patterns may influence wedge-tailed shearwaters foraging strategies.

If the light of the moon is advantageous to foraging wedge-tailed shearwaters, they may exploit nights around the full moon to extend foraging time and this would be observable as increased foraging activity under moonlit conditions. If nocturnal foraging is linked to the DVM of mesopelagic prey toward the surface at night, we would expect to find an isotopic signature in blood plasma correlated to the proportion of nocturnal foraging, showing a shift in prey between diurnal and nocturnal feeding. Stable isotopes can be used to examine trophic relationships, and they have been used to study niche partitioning that results from different prey or foraging habitats / resource use of consumers (e.g. [START_REF] Navarro | Ecological segregation in space, time and trophic niche of sympatric Planktivorous petrels[END_REF][START_REF] Pontón-Cevallos | Understanding resource partitioning in sympatric seabirds living in tropical marine environments[END_REF]Rayner et al., 2016). Finally, if shearwaters avoid returning to the colony in order to reduce predation risk from predators that benefit from brighter moonlight, they should preferentially return to the colony during the moonless part of the night.

While the predation avoidance hypothesis in relation to lunar cycle has been extensively tested by analyzing seabird activity patterns at colonies (e.g. [START_REF] Bretagnolle | Effet de la lune sur l'activité des pétrels (classe Aves) aux îles Salvages (Portugal)[END_REF][START_REF] Mougeot | Predation risk and moonlight avoidance in nocturnal seabirds[END_REF][START_REF] Bourgeois | Yelkouan shearwater Puffinus yelkouan presence and behaviour at colonies: not only a moonlight question[END_REF], few studies simultaneously focused on nocturnal foraging activity (but see Rubolini et al., 2015, which

found that Scopoli shearwaters

Calonectris diomedea increased their diving activity during full moon nights, but interpreted longer trips around the full moon to be driven by predation avoidance on land rather than higher foraging opportunities at sea). Moreover, most studies on lunar effects on the nocturnal, at-sea activity of seabirds, have been conducted using global location sensor (GLS). These data, only provide information on the time spent on water (e.g. [START_REF] Phalan | Foraging behaviour of four albatross species by night and day[END_REF][START_REF] Dias | the day or the night shift? Foraging schedules of Cory's shearwaters vary according to marine habitat[END_REF][START_REF] Cruz | At-Sea Behavior Varies with Lunar Phase in a Nocturnal Pelagic Seabird, the Swallow-Tailed Gull[END_REF], but prevent determining what drives that behavior, i.e. whether increased time spent on water during moonlit periods represent foraging activity or loafing. Using highresolution GPS data, the present study aimed at unravelling the effects of moon illumination and lunar phase on both nocturnal at-colony activity and at-sea foraging in wedge-tailed shearwaters, to understand how they shape their activities. We used miniaturized GPS-loggers to obtain a fine-scale trajectory of foraging trips during breeding season and accurately define resting, commuting and foraging events. We evaluated the proportion of time spent foraging during daytime and night-time and studied lunar phase and moon presence effects upon feeding trip duration, time of return to the colony and at-sea foraging. Finally we performed stable isotope analysis on blood plasma from all individuals, to determine whether we could identify diet differences associated with nocturnal foraging activity established through GPS tracking.

Material and methods

Ethical statement

All animal experimentation met the Animal Care Committee (ABS) / Association for the Study of Animal Behaviour (ASAB) guidelines for ethical treatment of animals. Permits to handle birds at Mato and Canard fields sites were delivered by New Caledonia's Province Sud (permits nos. 609-2014/ARR/DENV, 2903-2015/ARR/DENV and 2695-2016/ARR/DENV), and at Pindai and Tiambouene fields sites by New Caledonia's Province Nord (permits nos.

161214_AC 2303_ 2016 and 161214_AC2304_2017).

Field work

Field trips were conducted at four field sites in New Caledonia in the Coral Sea, South-west Pacific, which is home of 500,000 breeding pairs of wedge-tailed shearwaters [START_REF] Pandolfi | Seabirds of the Southern Lagoon of New Caledonia; Abundance and Threats[END_REF]. In this geographic area, the wedge-tailed shearwater breeding season begins around the end of October with the return of breeding adults to colonies and is completed at the end of May when chicks fledge (McDuie and Congdon, 2016). GPS-loggers were fitted on breeding adults during the chick-rearing period (from March to April) during two successive years (2017 and 2018) at four breeding sites. One study colony is located on the main island of New-Caledonia (Fig. 1): Pindaï (21.354°S, 164.954°E) where 37 and 7 breeders were equipped in 2017 and 2018, respectively. The three other study sites are located on lagoon islets: Mato (22.55°S, 166.80°E) where 20 and 7 breeders were equipped in [START_REF] Wood | Generalized Additive Models: An Introduction with R[END_REF]2018, respectively, Canard (22.31°S, 166.31°E) where 11 breeders were equipped in 2017, and Tiambouene (20.38°S, 164.04°E) where 17 breeders were equipped in 2018. Breeding adults were fitted with either 4.5 g Ecotone, 6 g Lotek, 5 g Pathtrack or 12.5 g TechnoSmart GPS-loggers, representing 1 to 3% of wedge-tailed shearwater body weight (413 ± 40 g in the present study), i.e. below the limit commonly accepted to limit behavior modification [START_REF] Phillips | Effects of satellite transmitters on albatrosses and petrels[END_REF]. The lightest GPS-loggers (Ecotone, Lotek and Pathtrack) were attached to three tail feathers using Tesa® tape [START_REF] Mcduie | Oceanographic drivers of near-colony seabird foraging site use in tropical marine systems[END_REF], while the heaviest GPS-loggers (Technosmart) were back-mounted to ensure balance during flight would not be affected [START_REF] Vandenabeele | Excess baggage for birds: inappropriate placement of tags on gannets changes flight patterns[END_REF]. Locations were recorded every 15 min. Birds were captured by hand at their burrow entrance before feeding their chicks. Colonies were monitored every night to recapture birds for logger recovery. A maximum of 0.4 ml of blood was collected on recapture from the tarsal vein using a 0.5 ml 29G syringe. Blood samples were centrifuged within 1 h from collection to separate plasma and blood cells that were then stored separately in 70% ethanol until stable isotope analyses were run.

Definition of night-time, moonlight intensity and lunar phase

In order to investigate the effect of moonlight on wedge-tailed shearwater foraging behaviour, the night was defined as the period between astronomical dusk and the beginning of the astronomical dawn (i.e. when the geometric center of the Sun's disk is 18° below the horizon).

Astronomical dusk and dawn, moon rise and set were computed at each location recorded by GPS-loggers using the R "suncalc" package [START_REF] Agafonkin | suncalc: Compute Sun Position, Sunlight Phases, Moon Position and Lunar Phase[END_REF], while moonlight intensity and lunar phase were determined at each location with the R package "lunar" [START_REF] Lazaridis | lunar: Lunar Phase & Distance, Seasons and Other Environmental Factors[END_REF]. Moonlight intensity was a value comprised between 0 and 1, 0 being the illumination during the new moon or during the moonless part of the night (before moonrise or after moonset), and 1 the illumination during the brightest full moon. Lunar phase was a value in radians, 0 corresponding to new moon, π/2 to first quarter (waxing moon), π to full moon and 3π/2 to last quarter (waning moon).

Foraging trip characteristics

Data from a total of 179 foraging trips were collected during 2017 (n = 126) and 2018 (n = 53) breeding seasons from 99 GPS-tracked individuals. Complete tracks, starting from the departure of the bird and ending at its return to the burrow, represented 85% of the total number of tracks. Trip duration (days), total distance travelled and maximum distance from the colony (km) were computed using the R package "trip" [START_REF] Michael | Trip: Tools for the Analysis of Animal Track Data[END_REF]. When tracks were incomplete, trip duration was estimated using the individual return date based on observation of birds back at the colony. Durations of nine incomplete tracks were impossible to estimate, and these tracks were removed from the analysis, resulting in a total of 170 trips being considered for trip duration analysis. Trips presenting gaps (n = 20) were removed from total distance travelled analysis, and incomplete trips (i.e. when the battery stopped before the individual began its return to the colony, n = 16) were removed from maximal distance travelled analysis. During the chick-rearing period, pelagic seabirds have to concurrently provide food to their chicks and meet their own needs using zones of high foraging competition near their colony [START_REF] Furness | Seabird colony distributions suggest competition for food supplies during the breeding season[END_REF][START_REF] Lewis | Evidence of intra-specific competition for food in a pelagic seabird[END_REF]. In wedge-tailed shearwaters, longer trips are undertaken to ensure self-provisioning whereas shorter trips focus on chick provisioning [START_REF] Congdon | Dual-foraging and co-ordinated provisioning in a tropical Procellariiform, the wedge-tailed shearwater[END_REF][START_REF] Mcduie | Breeding tropical shearwaters use distant foraging sites when self-provisioning[END_REF][START_REF] Mcduie | Oceanographic drivers of near-colony seabird foraging site use in tropical marine systems[END_REF][START_REF] Weimerskirch | At-sea movements of wedge-tailed shearwaters during and outside the breeding season from four colonies in New Caledonia[END_REF]. Thus, we differentiated in this study long trips (> 3 days, n = 50) and short trips (≤ 3 days, n = 119).

Arrival time at the colony

The time of arrival after a foraging trip was calculated using the first GPS location recorded on land, inside the colony area (i.e the contour of the islet, or within 1 Km around our study).

Twenty tracks presenting gaps did not allow us to determine the accurate time and were excluded from this analysis. The arrival time was calculated for the 159 remaining tracks with an estimated accuracy of 15 min. During waxing moon nights, the moon is present in the first part of the night then sets, while during waning moon nights, the moon rises during the night.

To investigate the effect of moon presence on wedge-tailed shearwaters arrival time at the colony, we determined whether birds arrived at the colony during the moonless or moonlit part of the night, or even before the astronomical dusk, for each lunar phase.

Behavioral assessment

Expectation Maximization binary Clustering (EMbC) algorithm [START_REF] Garriga | Expectation-maximization binary clustering for behavioural annotation[END_REF], a variant of the expectation maximization algorithm in maximum likelihood estimation of Gaussian mixture models, was used to determine wedge-tailed shearwaters behavior during their foraging trips using the R package "EMbC" [START_REF] Garriga | Expectation-maximization binary clustering for behavioural annotation[END_REF]. EMbC is a robust multivariate clustering algorithm based on sinuosity and speed of the trajectory calculated using loxodromic distances and bearings of the tracks to determine animal behavior. It requires few prior assumptions, assuming that turn angles between consecutive locations indicate searching or foraging, while straight bouts can be associated with resting (slow) and commuting (fast) [START_REF] Garriga | Expectation-maximization binary clustering for behavioural annotation[END_REF]. This method has been used to assess ecologically meaningful behaviors from geolocation data for a range of seabird species, including Procellariiforms [START_REF] Bennison | Search and foraging behaviors from movement data: A comparison of methods[END_REF][START_REF] Clay | Divergent foraging strategies during incubation of an unusually wide-ranging seabird, the Murphy's petrel[END_REF][START_REF] De Grissac | Early-life foraging: Behavioral responses of newly fledged albatrosses to environmental conditions[END_REF][START_REF] Mendez | Ontogeny of foraging behaviour in juvenile redfooted boobies (Sula sula)[END_REF]. Each GPS location was assigned with one of the four behaviors determined by the algorithm according to speed and turning angle: resting (low speed, low turning angle), commuting (high speed, low turning angle), extensive search (high speed, high turning angle) or intensive foraging (low speed, high turning angle). Resting corresponded to birds sitting on the water, and commuting to birds transiting between the colony and feeding areas, or between feeding areas.

In order to estimate individual daily activity patterns, the total number of each of the four behaviors identified by EMbC was summed per hour of the day and divided by the total number of behaviors per hour, thus representing relative proportion of each behavior according to the time of the day. Proportions of each behavior per individual were also computed and compared between the day, the moonlit part of the night and the moonless part of the night in order to determine if behaviour varies according to the presence of the moon and if wedge-tailed shearwaters adopted a similar behavior during the moonlit part of the night and during the day.

Tracks containing<40 GPS locations were excluded from the analysis because they could not effectively represent the activity pattern. Cloud cover was not taken into account in the analysis, due to the poor temporal resolution of the observational data available (minimum 1 observation per day), which does not allow to determine the influence of the cloud cover on light intensity throughout the night.

Stable isotope analyses

Stable isotopic ratios were used to test for diet or foraging differences between night and day feeding of GPS-tracked wedge-tailed shearwaters. For this purpose, isotopic ratio for stable carbon ( 13 C/ 12 C, expressed as δ 13 C) and nitrogen ( 15 N/ 14 N expressed as δ 15 N) were analyzed in blood plasma of each individuals. δ 15 N values are generally used as a proxy of the trophic level [START_REF] Minagawa | Stepwise enrichment of 15 N along food chains: Further evidence and the relation between δ 15 N and animal age[END_REF], allowing to test whether individuals fed on different prey during the day and at night. Carbon stable isotope values (δ 13 C) mainly reflect the foraging habitat / resource use of consumers if significant gradients exist at the base of food webs, which seem less pronounced in the tropics [START_REF] Jaeger | Seabird satellite tracking validates the use of latitudinal isoscapes to depict predators' foraging areas in the Southern Ocean[END_REF][START_REF] Newsome | A niche for isotope ecology[END_REF]. They were used here to test a difference in prey habitat (e.g. offshore vs. onshore, benthic vs. pelagic) between day and night. Plasma isotopic values reflect diet integrated 3 to 4 days prior to sampling, [START_REF] Hobson | Turnover of 13 C in Cellular and Plasma Fractions of Blood: Implications for Nondestructive Sampling in Avian Dietary Studies[END_REF]. Plasma was therefore used to assess recently integrated food items by individuals, most likely during their last recorded trip.

Since lipids can affect plasma δ 13 C values, they were removed using 2:1 chloroform: methanol mixture [START_REF] Hobson | Turnover of 13 C in Cellular and Plasma Fractions of Blood: Implications for Nondestructive Sampling in Avian Dietary Studies[END_REF]. Between 0.5 and 5 mg of dried plasma were repeatedly (2-3 treatments) shaken for one hour in 4 ml of the solvent. The sample was then centrifuged at 4000 g for 5 min and the supernatant containing the lipids was discarded. Lipid-free pellets were dried at 60 °C.

Sub-samples of plasma and red blood cells were weighed (0.3 mg) with a microbalance and packed into tin cups. Relative abundance of C and N isotopes were determined with a continuous flow mass spectrometer (Thermo Scientific Delta V Advantage) coupled to an elemental analyzer (Thermo Scientific Flash EA 1112). Results are presented in the δ notation relative to Vienna PeeDee Belemnite and atmospheric N2 for δ 13 C and δ 15 N, respectively.

Replicate measurements of internal laboratory standards (acetanilide) indicated measurement errors < 0.10‰ for both δ 13 C and δ 15 N values.

Statistical analyses

All statistical and spatial analyses were performed using R 3.5.1 (R Core [START_REF] Core | R: A language and environment for statistical computing[END_REF].

Correlation between trip duration and maximum distance from the colony was tested using a Pearson correlation test. In order to test whether birds adjusted their trip duration according to the lunar phase, General Additive Model (GAM) assuming a Poisson error distribution was applied, with trip duration as the dependent variable and lunar phase at the departure of the colony as fixed factor. Models were applied separately to chick-provisioning and selfprovisioning trips. GAMs were created using the "mgcv" R package [START_REF] Wood | Generalized Additive Models: An Introduction with R[END_REF]. Differences in the proportion of each behavior according to day or night, and moonless or moonlit part of the night were tested using Wilcoxon-Mann-Whitney rank sum-tests. Generalized Linear Models (GLMs) with Gaussian family and logit link function were applied on δ 15 N or δ13C values with proportion of time spent to forage at night, site and year as explanatory variables.

All results are presented as mean ± standard error.

Results

Foraging trip characteristics

The distribution of foraging trip durations suggests a bi-modal distribution with several trips lasting from 1 to 3 days, and longer trips lasting from 4 to 13 days (Supplementary Fig. S1).

Chick-feeding trip mean duration was 1.19 days (±0.07, n = 120, Table 1), mean distance travelled 276 km (±20, n = 100) and mean maximum distance from the colony 102 km (±8, n = 101). Self-feeding trip mean duration was 7.31 days (±0.37, n = 50), mean distance travelled 1452 km (±102, n = 30) and mean maximum distance from the colony 401 km (±21, n = 53).

Pearson correlation tests showed that trip duration and maximum distance from the colony were correlated on average at 88.6% ± 3.8% by site. Thus, we will consider only trip duration in the following results.

Effect of lunar phase on foraging trip duration

GAM did not reveal a significant effect of the lunar phase on chick provisioning trips (≤ 3 days) duration (Fig. 2; adjusted R² = -0.005, deviance explained = 0.385%, n = 120, edf = 1, p = 0.521) but duration of self-provisioning trip (> 3 days) was significantly longer when birds departed around the full moon (Fig. 2; adjusted R²= 0.200, Deviance explained = 25.5%, n = 50, edf = 2.702, p = 0.038).

Arrival time at the colony

Among the 160 trips for which arrival time at the colony could be calculated, 19 (12%) took place during the day, before astronomical dusk or after astronomical dawn. Among the 141 arrivals that took place at night, 55 (39%) occurred during moonless conditions and 86 (61%) under moonlit conditions (Fig. 3). During waxing and waning moons, when the moon is present only during a part of the night, most individuals reached the colony under moonlit conditions (64.3% during waxing moon, 53.6% during waning moon). Around the new moon, the moon is absent throughout the night and it is the only case where most of the arrivals took place during moonless conditions (76.5%), the others occurring before astronomical dusk (23.5%).

Activity patterns and lunar cycle

When at sea, foraging behavior represented the most important activity during daytime and the second most important during the night (Table 2, Fig. 4). Individuals spent most of their time resting on the water during the night, while during the day it was the least represented behavior.

Commuting behavior occurred mainly at dusk and dawn. At night, wedge-tailed shearwater behavior was significantly affected by moonlight, with foraging activity occurring more frequently during moonlit than during moonless periods of the night (W=3964.5, p < .001; Fig. 5). Furthermore, they foraged more than they rested during moonlit periods (W = 3841.5, p = .001) and conversely rested more than foraged during moonless periods (W = 779.5, p < .001), even though foraging remained lower during moonlit periods of the night than during daylight (W = 4695, p = .008; Fig. 5).

On average 72.1% (±1.6) of foraging activity occurred during daylight. Daylight foraging dropped to 68.0% (±1.7) when the foraging trips included ≥1 night/s away from the colony, with individual variability ranging between 4 and 94% of total foraging activity.

Stable isotope analyses

Linear regression models revealed that the δ 15 N values in blood plasma were significantly affected by the percentage of nocturnal foraging (estimate = -1.98, CI95: [-3.930: -0.034];

Table 3) indicating a decrease in δ 15 N values along with the time spent foraging at night. The δ 15 N values were significantly higher during 2018 compare to 2017 (estimate = 1.17, CI95:

Discussion

Wedge-tailed shearwaters performing chick-provisioning trips primarily returned to the colony under moonlit conditions and lunar phase did not significantly affect chick-provisioning trip length, indicating that these trips would be conducted regardless of the lunar phase. It is important for shearwaters to maintain regular chick provisioning and they can achieve this with short duration trips that are near the colony [START_REF] Mcduie | Oceanographic drivers of near-colony seabird foraging site use in tropical marine systems[END_REF].

By contrast, when performing self-provisioning foraging trips, trip lengths were longer around the full moon than under the new moon. Wedge-tailed shearwaters are known to forage at more distant locations when self-provisioning [START_REF] Congdon | Dual-foraging and co-ordinated provisioning in a tropical Procellariiform, the wedge-tailed shearwater[END_REF][START_REF] Mcduie | Breeding tropical shearwaters use distant foraging sites when self-provisioning[END_REF] where prey resources may be richer (e.g. [START_REF] Miller | Importance of tropical tuna for seabird foraging over a marine productivity gradient[END_REF][START_REF] Weimerskirch | Alternate long and short foraging trips in pelagic seabird parents[END_REF]. We also found that the maximum distance of longer trips was farther from the colony that for shorter trips so WTSH could be taking advantage of increased light available around the full moon to extend foraging time and food assimilation when self-provisioning. This behavior has been previously documented in another shearwater species, the Scopoli's shearwater Calonectris diomedea, where [START_REF] Rubolini | The Effect of Moonlight on Scopoli's Shearwater Calonectris diomedea Colony Attendance Patterns and Nocturnal Foraging: A Test of the Foraging Efficiency Hypothesis[END_REF] interpreted the longer trips taken by shearwaters under moonlit conditions as a predation avoidance strategy. Furthermore, in that study, the majority of individuals returned to the colony and entered burrows once the night was moonless. Moonlight avoidance when attending colonies has also been documented in other Procellariid species, generally reflected by a lower number of individuals at the colony during the nights around the full moon [START_REF] Bourgeois | Yelkouan shearwater Puffinus yelkouan presence and behaviour at colonies: not only a moonlight question[END_REF][START_REF] Bretagnolle | Effet de la lune sur l'activité des pétrels (classe Aves) aux îles Salvages (Portugal)[END_REF][START_REF] Mougeot | Predation risk and moonlight avoidance in nocturnal seabirds[END_REF][START_REF] Riou | Predation risk and reproductive effort: impacts of moonlight on food provisioning and chick growth in Manx shearwaters[END_REF]. In contrast, a recent study indicated that streaked shearwaters Calonectris leucomelas did not avoid moonlight when arriving at the colony [START_REF] Van Tatenhove | Streaked shearwater Calonectris leucomelas moonlight avoidance in response to low aerial predation pressure, and effects of wind speed and direction on colony attendance[END_REF]. In our study, 53% of wedge-tailed shearwaters returned from chickand self-provisioning foraging trips during moonlit periods and 12% of the individuals reached the colony before astronomical dusk. Even when the moon was absent during part of the night, when waxing or waning, only 39% of wedge-tailed shearwaters returned during moonless periods, which contradicts the predation avoidance hypothesis. Thus, wedge-tailed shearwater trip duration does not seem to be related to the avoidance of predation on land in New Caledonia, despite evidence of predation by feral cats Felis catus and peregrine falcons Falco peregrinus in at least two colonies (pers. obs.). On the other hand, we cannot exclude that nonbreeding individuals may have avoided moonlight, a phenomenon observed in other petrel and shearwater species [START_REF] Bourgeois | Yelkouan shearwater Puffinus yelkouan presence and behaviour at colonies: not only a moonlight question[END_REF].

During the breeding season, wedge-tailed shearwaters primarily foraged during the day, commuted to and from the colony at dawn and dusk and rested at night. However, the unexpectedly active nocturnal foraging differed from most previous studies that showed little nocturnal foraging in closely related, large shearwaters (600 to 950 g; flesh footed shearwater Ardenna carneipes: 2% of dives during night-time, [START_REF] Rayner | Migration and diving activity in three non-breeding flesh-footed shearwaters Puffinus carneipes[END_REF]sooty shearwater Ardenna grisea: <5% of dives, [START_REF] Shaffer | Spatiotemporal habitat use by breeding sooty shearwaters Puffinus griseus Scott[END_REF]streaked shearwater: 5% of dives, Matsumoto et al., 2012; great shearwater Ardenna gravis: <0.5% of dives, [START_REF] Ronconi | Diving of great shearwaters (Puffinus gravis) in cold and warm water regions of the South Atlantic Ocean[END_REF] short-tailed shearwaters Ardenna tenuisrostris: lack of dive during the night, [START_REF] Raymond | Shearwater foraging in the Southern Ocean: The roles of prey availability and winds[END_REF]. One exception of this limited nocturnal foraging activity in medium to large shearwaters is the pinkfooted shearwater (Ardenna creatopus, ~700 g) which performed 22% of its dives during the night [START_REF] Adams | Diving behavior of Pinkfooted Shearwaters Ardenna creatopus rearing chicks on Isla Mocha, Chile[END_REF], which is similar to the 28% nocturnal foraging by wedgetailed sheawaters in the present study. Nevertheless, we cannot exclude that our results may be specific to our study populations and/or years as spatial and temporal adjustment of foraging activity has been observed in other seabird populations.

Cory's shearwaters Calonectris diomedea, for example, become nocturnal foragers when wintering in colder, deeper seas areas of the ocean where the DVM is more prevalent, particularly during moonlit nights [START_REF] Dias | the day or the night shift? Foraging schedules of Cory's shearwaters vary according to marine habitat[END_REF]. Interestingly, wedge-tailed shearwaters foraging activity under moonlit conditions became more similar to their diurnal pattern, whereby foraging exceeded resting. Moonlight could provide sufficient light for these predators that, as with many procellariids, rely on visual cues at small spatial scale to hunt for small pelagic prey such as squids and fish [START_REF] Brooke | Albatrosses and Petrels across the World[END_REF][START_REF] Harrison | Hawaiian seabird feeding ecology[END_REF]. Remaining at sea for nocturnal foraging consequently delayed these individuals' return to the colony which drove the increase in moonlit commuting behavior. These results are consistent with previous studies conducted on petrels [START_REF] Dias | Distribution and at-sea activity of a nocturnal seabird, the Bulwer's petrel Bulweria bulwerii, during the incubation period[END_REF][START_REF] Ramos | Global spatial ecology of three closely-related gadfly petrels that breed in Macaronesia[END_REF], shearwaters [START_REF] Dias | the day or the night shift? Foraging schedules of Cory's shearwaters vary according to marine habitat[END_REF][START_REF] Yamamoto | The lunar cycle affects at-sea behaviour in a pelagic seabird, the streaked shearwater, Calonectris leucomelas[END_REF] and albatrosses [START_REF] Phalan | Foraging behaviour of four albatross species by night and day[END_REF], that highlighted a greater movement or foraging activity during moonlit nights. Thus, we think it more likely that longer trips around the full moon are linked to increased foraging opportunities than predation avoidance.

Another factor that may cause wedge-tailed shearwaters to remain foraging at-sea nocturnally is the DVM exhibited by mesopelagic fish species [START_REF] Spear | Foraging dynamics of seabirds in the eastern tropical Pacific Ocean[END_REF] such as Myctophidae, known to be consumed by wedge-tailed shearwaters [START_REF] Komura | DNA barcoding reveals seasonal shifts in diet and consumption of deep-sea fishes in wedge-tailed shearwaters[END_REF]. If DVM makes these species available during the night to shallow divers, such as wedge-tailed shearwaters [START_REF] Spear | Foraging dynamics of seabirds in the eastern tropical Pacific Ocean[END_REF], we would expect to see this reflected in divergent values of the stable isotopes δ 13 C and/or δ 15 N [START_REF] Inger | Applications of stable isotope analyses to avian ecology[END_REF] according to the time spent foraging at night. The absence of a relationship between δ 13 C values and the proportion of nocturnal foraging may indicate that wedge-tailed shearwaters target similar habitats/species when foraging at night. Alternatively, this could be due to a lack of contrast in δ 13 C values at the base of tropical food webs [START_REF] Ménard | Isotopic evidence of distinct feeding ecologies and movement patterns in two migratory predators (yellowfin tuna and swordfish) of the western Indian Ocean[END_REF], which prevents differentiation between the foraging habitats used. By contrast, the decrease in δ 15 N values in relation to the percentage of nocturnal foraging supports a possible shift in prey consumption between day and night which is consistent with the assumption that wedge-tailed shearwaters could take advantage of the nocturnal migration of mesopelagic prey to the surface. However, this was a relatively weak relationship compared with the strong differences in δ 15 N values between year and sites and, as such, must be interpreted carefully. Additional diet analyses based on eDNA would be useful to confirm these results, and to better understand the diet of wedge-tailed shearwaters when foraging at night.

Based on 179 high resolution WTSH foraging trips, this study strengthens the evidence that the moon strongly affects foraging activity during the breeding season in Procellariids. By tuning self-provisioning foraging trip durations, WTSH were able to extend their foraging timewindow and forage day and night by taking advantage of the lengthened light available during the most favorable periods around full moon. This behavioral adjustment could reduce intraand interspecific competition for resources with other abundant, and mainly diurnal foraging seabird species that nest in New Caledonia [START_REF] Spaggiari | New Caledonian seabirds. Compend. Mar. species New Caledonia[END_REF]. This could be of significant importance in an area where very large seabird populations [START_REF] Pandolfi | Seabirds of the Southern Lagoon of New Caledonia; Abundance and Threats[END_REF] rely on poor productivity, oligotrophic waters [START_REF] Menkes | Seasonal oceanography from physics to micronekton in the south-west pacific[END_REF]. Table 1. Foraging parameters of wedge-tailed shearwaters studied during the 2017-2018 breeding season in New Caledonia.

Table 2. Proportion (mean ± SE) of behaviour (foraging, extensive search, resting, commuting) carried out by breeding wedge-tailed shearwaters in New Caledonia. Results are presented for night and day confounded (All), during the day (Day), during the night (Night), during the moonless part of the night (Moonless) or during the moonlit part of the night (Moonlit).

Foraging Relocating Resting

Commuting All 0.32 ± 0.15 0.12 ± 0.10 0.27 ± 0.28 0.28 ± 0.21 Day 0.38 ± 0.13 0.19 ± 0.08 0.09 ± 0.07 0.34 ± 0.14 Night 0.28 ± 0.15 0.07 ± 0.08 0.39 ± 0.30 0.24 ± 0.23 Moonlit 0.34 ± 0.15 0.10 ± 0.08 0.25 ± 0.23 0.31 ± 0.21 Moonless 0.23 ± 0.13 0.05 ± 0.08 0.56 ± 0.29 0.16 ± 0.22

  [0.752: 2.906]) and significantly higher in Tiambouene colony compare to Canard (estimate = -1.15, CI95: [-3.135: -0.463]). The model also highlighted a significant combined-effect of the percentage of nocturnal foraging at Pindai (estimate = 2.27, CI95: [0.203: 4.329]), indicating that the δ 15 N values were differently affected by the percentage of nocturnal foraging for this colony. No significant effect of percentage of nocturnal foraging on the blood plasma δ 13 C values was shown (estimate = 0.25, CI95: [-0.589: 1.102]).

Figure 1 .

 1 Figure 1. Map of New Caledonia, showing the location of the four wedge-tailed shearwaters breeding colonies used in this high-resolution GPS study of foraging behavior. Inset shows the position of New Caledonia at the eastern edge of the Coral Sea.

Figure 2 .

 2 Figure 2. Results from generalized additive models that assessed self-provisioning and chickprovisioning foraging trip durations of WTSH from 4 study colonies on New Caledonia, and the relationships with the phase of the moon at the time of departure from the colony. The figure shows a clear relationship with self-provisioning trips (n = 50, dashed line and circles represent individual trips), but no effect of the moon on chick-provisioning trips (n = 120, solid line and triangles).

Figure 3 .

 3 Figure 3. Frequency distribution of wedge-tailed shearwaters arrivals to the colony according to the presence of the moon for (a) all trips, (b) chick-provisioning trips and (c) self-provisioning trips. Sample sizes (number of arrivals to the colony) are as follows: moonless part of nights, n = 55; moonlit part of the night, n = 86; outside the complete night, n = 19.

Figure 4 .

 4 Figure 4. Percentage of time allocated to each behavior (foraging, extensive search, resting or commuting) by New Caledonia breeding wedge-tailed shearwaters, according to the time of day. The dark grey parts represent the night, the light grey parts the dawn and dusk and the white part the day.

Figure 5 .

 5 Figure 5. Proportion (mean ± SE) of behaviors (foraging, extensive search, resting, commuting) assigned along the tracks of New Caledonia breeding wedge-tailed shearwaters according to the presence of the sun and the moon (day, moonlit part of the night or moonless part of the night).

Table 3 .

 3 Summary tables of linear models explaining trends in nitrogen (δ 15 N) and carbon (δ 13 C) isotopic values from blood plasma of wedge-tailed shearwater as a function of their percentage of nocturnal foraging, colony and year of sampling. Intercept represent the year 2017 and the site Canard islet. The numbers of * indicates the degree of significance (* P<0.05; ** P<0.01; *** P<0.001.

Figure S1 .

 S1 Figure S1. Histogram of the foraging trip duration of wedge-tailed shearwaters GPS tracked in New Caledonia during 2017 and 2018 breeding season.

Acknowledgements

We thank the many field workers involved in the field studies in New Caledonia, especially Aymeric Bodin, Guillaume Chagneau, Julien Dijoux, Mathieu Mathivet, Aurore Pujapujane, Angélique Pagenaud, Nicolas silva, Maële Brisset, Maxime Neaoutyine, Corentin Lemesle and Hélène de Méringo. We also thanks for field work facilities the Province Nord and Province Sud environmental services. We also appreciate support of M. Brault-Favrou from the Plateforme Analyses Elémentaires of the LIENSs laboratory for proceeding the samples for the stable isotope analyses, and of G. Guillou from the Plateforme Analyses Isotopiques of the LIENSs laboratory for running stable isotope analyses. Thanks to the CPER (Contrat de Projet Etat-Région) and the FEDER (Fonds Européen de Développement Régional) for funding the IRMS of LIENSs laboratory. The IUF (Institut Universitaire de France) is acknowledged for its support to P. Bustamante as a Senior Member.

Fundings

This work was supported by the European Union BEST 2.0 project "Biopelagos" (grant number 1070-2015) and the Province Nord (grant number 15C493). Ecole Doctorale du Pacifique and Université de la Nouvelle-Calédonie provided A.R. with a PhD fellowship.

Declaration of Competing Interest

The authors declare that the research was conducted in the absence of any conflict of interest.


Mathieu Langlais
email: mathieu.langlais@u-bordeaux.fr

Aude Chevallier

Célia Fat Cheung

Jérémie Jacquier

Benjamin Marquebielle

Nicolas Naudinot

The Pleistocene-Holocene transition in Southwestern France: A Focus on the Laborian

Keywords:

During the Pleistocene-Holocene transition, the European archaeological records can be divided into two broad entities -the Epigravettian in the northern Mediterranean Basin and industries characterized by the return of a well-developed blade technology in northwestern Europe. This large Western European techno-complex comprises several cultural traditions defined essentially by various types of projectile points. One of these cultures, the Laborian, occupies an area at the crossing of northern traditions (Ahrensbourgian) and the Epigravettian techno-complex. Situated between the Azilian and the Mesolithic, the Laborian (ca 12.5-11 Ka cal. BP) is, paradoxically, poorly defined in southwestern France where it was initially defined. In fact, data for this culture is essentially available in the surrounding regions and especially in northern and western France. Revaluation of key Laborian lithic assemblages as well as the discovery of new sites today draw a new picture of the various cultural traditions occupying this large area around 12 Ka cal. BP). Despite the scarcity of data on hunted fauna, we can observe the dominance of the exploitation of large game typical of open temperate landscapes. Osseous industry is also rare but we note the maintenance of bone barbed points in few sites. Artistic conventions (engraved pebbles or bones) show several symbolic innovations, such as the development of a unique zoomorphic art. Lithic hunting weaponry essentially based around point forms, much like during the Azilian, allow to highlight two chronological phases along the Laborian culture: an older phase with straight backed points with truncated bases (Malaurie points) and bitruncated backed blades ("rectangles") and a recent phase with pointed backed bladelets (Blanchères points) and bitruncated trapezoids. The production of large, standardized, straight blades with flat cross-sections during the Laborian reveals clear similarities with concepts recognized in Belloisian collections even if blade lengths rarely reach the standards known on these sites. Finally, the technological study of domestic stone tools and hunting weaponry is an effective means for reconstructing larger scale evolution processes influencing these last Pleistocene societies and the persistence of their traditions into the European Mesolithic.

Introduction

During the Pleistocene-Holocene climate transition, Europe was crossed by several cultural currents, among which the Laborian lies at the interface between the northern (Epi/Ahrensburgian) and Mediterranean traditions (Epigravettian, Iberian Epimagdalenian). Coming after the Azilian and before the Mesolithic, the Laborian (ca 12.5-11 ka cal BP) remained paradoxically poorly studied in its eponymous region -the South-West of Francewhen compared to the work carried out in the North (e.g. [START_REF] Fagnart | Le Paléolithique supérieur récent et final dans le Nord de la France dans son cadre paléoclimatique[END_REF][START_REF] Fagnart | Les industries à grandes lames et éléments mâchurés du Paléolithique final du nord de la France : une spécialisation fonctionnelle des sites épi-ahrensbourgiens[END_REF][START_REF] Valentin | Les groupes humains et leurs traditions au Tardiglaciaire dans le Bassin parisien. Apports de la technologie lithique comparative[END_REF]2008, 2009;[START_REF] Bodu | Les faciès tardiglaciaires à grandes lames rectilignes et les ensembles à pointes de Malaurie dans le sud du Bassin parisien : quelques réflexions à partir de l'exemple du gisement du Closeau (Hauts-de-Seine)[END_REF] and West [START_REF] Naudinot | Les armatures lithiques tardiglacières dans l'Ouest de la France (Régions Bretagne et Pays de la Loire): proposition d'organisation chrono-culturelle et chaîne opératoire de fabrication[END_REF](Naudinot, , 2010[START_REF] Naudinot | La fin du Tardiglaciaire dans le Grand-Ouest de la France[END_REF] of the country. A few years ago, a first re-assessment of the Laborian was made in southwestern France (Langlais et al., 2014a). This collective work conducted thereafter on the eponymous site of La Borie del Rey (Blanquefort-sur-Briolance, Lot-et-Garonne), following on from the work by L. Coulonges and J.-M. Le Tensorer, proposed a subdivision of the Laborian into two phases, Early (encompassing the Protolaborian and Laborian) and Late (i.e. Epilaborian). During the workshop held in Bordeaux with specialists on the southern half of France and northern Italy, attention was focused primarily on the lithic industries and fauna (Langlais et al. dir., 2014). Several projects have also taken a fresh look at older and more recent collections [START_REF] Cheung | Comparaison des séquences aziliennes entre Dordogne et Pyrénées: état des travaux en cours[END_REF]Langlais et al., 2014b). Reviews have also provided a better understanding of the variability of technical behaviors during this period in both the Armorican Massif [START_REF] Naudinot | La fin du Tardiglaciaire dans le Grand-Ouest de la France[END_REF][START_REF] Jacquier | Approche fonctionnelle de l'outillage lithique à l'aube de l'Holocène dans le nord-ouest de la France[END_REF], Massif Central [START_REF] Langlais | La séquence archéostratigraphique du Cuze de Sainte-Anastasie (Cantal): nouvelle approche des industries lithiques du Paléolithique final au Mésolithique[END_REF] and the Pyrenees (Fat Cheung, 2015). Since 2016, the objective of the "Laborian Project" has been to review the different registers of material culture and symbolic system during this period and reflect on its chronological phasing. The overview we provide here is therefore the fruit of these recent years of study, reassessment and collective analysis revolving around the Laborian(s).

Corpus

The review of late glacial stratigraphies from southwestern France highlighted -further to the work of G. Célérier at Pont d'Ambon -the presence of Laborian assemblages above "Magdalenian-Azilian" sequences in sites that were dug early on, and in many cases a little too early on. The stratigraphic distribution of certain markers (essentially lithic weapon elements, see [START_REF] Langlais | Le Magdalénien récent: une technologie de pointes[END_REF] from the Upper Magdalenian (e.g. shouldered points, Laugerie-Basse or Teyjat points), Azilian (e.g. backed bipoints and different types of monopoints) and Laborian (e.g. Malaurie points, rectangles, Blanchères points, bitruncated trapezoids) reveals the varying levels of confidence as regards these archaeological sequences. Although they are quite coherent at Le Pont d'Ambon in Bourdeilles, Dordogne [START_REF] Célérier | L'abri sous roche de Pont d'Ambon à Bourdeilles (Dordogne)[END_REF], Boudadi-Maligne et al., 2018), the stratigraphies of Rochereil in Grand-Brassac, Dordogne [START_REF] Jude | La grotte de Rochereil, station magdalénienne et azilienne[END_REF]Mallye and Laroulandie, 2018), Le Morin in Pessac-sur-Dordogne, Gironde [START_REF] Bordes | L'azilianisation dans la vallée de la Dordogne les données de la Gare de Couze (Dordogne) et de l'abri Morin (Gironde)[END_REF]Mallye et al., 2018), Gare de Couze in Lalinde, Dordogne [START_REF] Fitte | Le Magdalénien VI de la Gare de Couze, commune de Lalinde, Dordogne[END_REF] or Le Roc d'Abeilles in Calviac, Dordogne [START_REF] Champagne | L'abri du Roc d'Abeilles à Calviac (Dordogne)[END_REF]) are more complex. This work brings into question the accretive cultural model put forward by F. Bordes and D. de Sonneville-Bordes at the end of the 1970s. Ultimately, the model of a Final Magdalenian that was gradually enriched by Azilian elements (based on mixed sequences) disrupted exploration of the Laborian. Other hitherto somewhat neglected collections, such as Auberoche in Le Change, Dordogne [START_REF] Daniel | Note sur l'abri d'Auberoche, commune du Change (Dordogne)[END_REF] or Gouërris in Lespugue, Haute-Garonne [START_REF] Saint-Périer | La grotte de Gouërris à Lespugue[END_REF], were reviewed and have now been attributed to the Laborian (Fat cheung, 2015; Langlais and Fat Cheung in progress). Revaluation of the eponymous collections of La Borie del Rey in Blanquefort-sur-Briolance, Lot-et-Garonne (Coulonges excavation) has provided a clearer insight into the chronological evolution of the Laborian (see below), notably through the morphotypes of lithic weapon elements (Langlais et al., 2014b). Among the other stratified sites undergoing revision, that of Le Cuze de Sainte-Anastasie in Cantal (Pierron-Derville collection and Delpuech-Fernandes excavation) also provides new data on the evolution of the Laborian [START_REF] Langlais | La séquence archéostratigraphique du Cuze de Sainte-Anastasie (Cantal): nouvelle approche des industries lithiques du Paléolithique final au Mésolithique[END_REF]. At the same time that these old collections were being reviewed, new sites have been discovered and excavated within the framework of scheduled archaeology operations, such as the cave-rock shelter of Peyrazet -in Creysse, Lot -presenting a sequence from the Upper Magdalenian through to the Late Laborian [START_REF] Langlais | Le Laborien récent de la grotte-abri de Peyrazet (Creysse, Lot)[END_REF]. A number of open-air sites investigated on scheduled or rescue excavations have provided more precise information as to the spatial organization of settlements structured around hearths, and raise questions about the function of the sites and mobility strategies of Laborian groups. Such is the case notably of the sites of La Fosse in Villiers-Charlemagne, Mayenne [START_REF] Naudinot | Socio-economic organization of Final Paleolithic societies: New perspectives from an aggregation site in Western France[END_REF], Portde-Penne in Penne d'Agenais, Lot-et-Garonne (Langlais et al., 2014b[START_REF] Detrain | Occupations de l'Epipaléolithique du site du camping du Saut à Port-de-Penne (Penne d'Agenais, Lot-et-Garonne)[END_REF], Manirac in Lectoure, Gers [START_REF] Beyneix | Blessure animale avec projectile conservé provenant du gisement de Manirac (Lectoure, Gers)[END_REF]Fat Cheung, 2015), Champ Chalatras in Les Martres d'Artière, Puy-de-Dôme [START_REF] Pasty | Le gisement épipaléolithique à pointes de Malaurie de Champ Chalatras (Les Martres d'Artière, Puy-de-Dôme[END_REF] and Vaise in Lyon, Rhône (Jallet and Bouvier dir., 2012 ;Treffort dir., 2017). Within the framework of the Laborian Project (2016-2018), we have compared petrographic, techno-typological and functional data on the lithic industries, as well as data on fauna and the bone industry. Here we present the main results from southwestern France.

Results

Prey species

Among the sites where faunal remains have been found, only those for which we are certain of their attribution to the Laborian have been taken into account in this study. In other words, making a distinction between Laborian, Azilian and even Magdalenian game animals is difficult in stratigraphic sequences that were dug a long time ago, such as Rochereil or Le Morin, unless by direct dating of certain remains (Mallye and Laroulandie, 2018;Mallye et al., 2018). Studies that have been published or are currently underway show a hunting spectrum that is often varied but is largely dominated by the large plain ungulates, while totally devoid of any glacial species in southwestern France (fig. 1). For Early Laborian, the work carried out by F. Delpech then J.-G. Ferrié at Le Pont d'Ambon c.2 shows a diversified spectrum dominated by aurochs, horses and then red deer [START_REF] Delpech | Les faunes du Paléolithique supérieur dans le Sud-Ouest de la France[END_REF]Célérier (dir.), 1994;[START_REF] Cheung | Comparaison des séquences aziliennes entre Dordogne et Pyrénées: état des travaux en cours[END_REF][START_REF] Boudadi-Maligne | Les chiens du Pont d'Ambon: statut, contexte et implications sociétales[END_REF]. The same three main prey species have been found at La Borie del Rey with wild boars [START_REF] Coulonges | Magdalénien et périgordien post-glaciaires: la grotte de la Borie del Rey (Lot-et-Garonne)[END_REF][START_REF] Gilbert | Contribution à l'étude des faunes de la fin des temps glaciaires et du début des temps postglaciaires[END_REF]Ferrié in Langlais et al., 2014b). At Port-de-Penne, level 1 is dominated by red deer, horse and bovid (of wich aurochs), whereas horse is the principal game from level 2 (A. Chevallier in progress). The aurochs is the principal game in Manirac, Gers [START_REF] Ducassé | Le gisement préhistorique de Manirac à Lectoure (Gers), actes des 7e et 8e journées des archéologues gersois[END_REF][START_REF] Gilbert | Contribution à l'étude des faunes de la fin des temps glaciaires et du début des temps postglaciaires[END_REF][START_REF] Beyneix | Blessure animale avec projectile conservé provenant du gisement de Manirac (Lectoure, Gers)[END_REF] and at Champ-Chalatras, Puy-de-Dôme [START_REF] Pasty | Le gisement épipaléolithique à pointes de Malaurie de Champ Chalatras (Les Martres d'Artière, Puy-de-Dôme[END_REF]. In Quercy, Malaurie rockshelter, in Lot (Laroulandie and Langlais directors, excavation in progress, fauna studied by S. Costamagno), yielded a spectrum dominated by red deer. The mesofauna was also exploited, such as beaver and rabbit at La Borie del Rey (Langlais et al., 2014b) and Le Pont d'Ambon [START_REF] Jones | Climate change, patch choice, and intensification at Pont d'Ambon (Dordogne, France) during the Younger Dryas[END_REF][START_REF] Cheung | Comparaison des séquences aziliennes entre Dordogne et Pyrénées: état des travaux en cours[END_REF] or the marmot in the Alps at La Passagère and Colomb [START_REF] Monin | Exploitation d'un écosystème alpin au Tardiglaciaire : Les chasseurs de marmottes (marmota marmota) du Vercors. Données environnementales, culturelles et économiques[END_REF]. For Late Laborian we can quote the dominance of red deer at Peyrazet cave-rockshelter [START_REF] Langlais | Le Laborien récent de la grotte-abri de Peyrazet (Creysse, Lot)[END_REF] and La Borie del Rey (Langlais et al., 2014b). In Normandy, Aurochs is the principal game in Alizay, Eure [START_REF] Bémilli | Une partie de chasse à l'Aurochs il y a 10000 ans. Le Locus 28704 d[END_REF] and in Loiret, site of Chevilly-Nant valley yielded some rests of fauna with horse [START_REF] Verjux | Le Mésolithique en région Centre: un état des recherches[END_REF]. Finally, it should also be pointed out that dogs have been shown to be present in the Early Laborian [START_REF] Célérier | Un chien dans l'Azilien de "Pont d'Ambon" (Dordogne) ?[END_REF][START_REF] Célérier | Données nouvelles sur l'âge des vestiges de chien à Pont d'Ambon[END_REF][START_REF] Chaix | A Preboreal dog from the northern Alps (Savoie, France)[END_REF][START_REF] Boudadi-Maligne | Les chiens du Pont d'Ambon: statut, contexte et implications sociétales[END_REF].

A scarce and monotonous bone industry

As far as the bone industry is concerned, few collections have been the subject of in-depth study for the moment: La Borie del Rey, Le Pont d'Ambon, Gouërris, Peyrazet and Port-de-Penne (see Chauvière & Marquebielle in Langlais et al., 2014b;see Pétillon in Langlais et al., 2015;[START_REF] Marquebielle | Une rupture dans le travail des matières osseuses entre le Paléolithique final et le Mésolithique? Quelques éléments de reflexion à partir de sites Nord aquitains[END_REF]. Despite biases due either to the scarcity of collections or the taphonomy of the sites, an initial review can be presented. For the moment, no evolution has been distinguished in equipment between the Early and Late Laborian. The bones have often been transformed by fracturing, notably of diaphyses. The fragments obtained have then been shaped by scraping, mainly to form awls and smoothers, and the shaping is limited to the active part in most cases. Mention should be made of signs of transversal sawing and longitudinal grooving in certain collections, which may indicate the use of more complex debitage methods. As regards cervid antler, we should note the presence at Le Pont d'Ambon of waste from the extraction of a broad rod from the posterior side of a deer antler, by a process of parallel double grooving [START_REF] Marquebielle | Une rupture dans le travail des matières osseuses entre le Paléolithique final et le Mésolithique? Quelques éléments de reflexion à partir de sites Nord aquitains[END_REF]. The main type of object made in this material is the barbed point, recorded in particular at Gouërris and Le Pont d'Ambon, but also, in all probability, at Le Mas d'Azil (ibid) and Le Morin (artefact dated directly to 10365 ± 45 BP; [START_REF] Barshay-Szmidt | New extensive focused AMS 14C dating of the Middle and Upper Magdalenian of the western Aquitaine/Pyrenean region of France (ca. 19-14 ka cal BP): Proposing a new model for its chronological phases and for the timing of occupation[END_REF]. Evidence is still lacking, however, to establish a formal association between the extraction of rods and barbed points in the same transformation scheme. A few examples of the production of objects on volume blanks of the bone section type can also be reported.

Results of use wear analysis of flint artefacts support this perception of a relative poverty of bone industry during the Early and Late Laborian. Flint tools implicated in the processing of bone or antler (essentially burins used in scraping and secondarily grooving motions) are always particularly scarce [START_REF] Jacquier | Analyse fonctionnelle des outillages lithiques et interprétations socioéconomiques du statut des sites tardiglaciaires du Buhot à Calleville (Eure) et de la Fosse à Villiers-Charlemagne (Mayenne)[END_REF][START_REF] Jacquier | Approche fonctionnelle de l'outillage lithique à l'aube de l'Holocène dans le nord-ouest de la France[END_REF][START_REF] Langlais | Le Laborien récent de la grotte-abri de Peyrazet (Creysse, Lot)[END_REF][START_REF] Langlais | La séquence archéostratigraphique du Cuze de Sainte-Anastasie (Cantal): nouvelle approche des industries lithiques du Paléolithique final au Mésolithique[END_REF] especially when compared to Magdalenian contexts. Flint tools typology also goes in this direction considering the scarcity of piercing tools (borers and becs) in Early and Late Laborian cultures.

Some particular symbolic behaviors

As far as portable art is concerned, certain collections have delivered pebbles with geometric engravings that clearly evoke the ancestral traditions of the Late Azilian: Champ Chalatras [START_REF] Pasty | Le gisement épipaléolithique à pointes de Malaurie de Champ Chalatras (Les Martres d'Artière, Puy-de-Dôme[END_REF]; le Roc in Gironde [START_REF] Lenoir | Le Magdalénien et l'Épipaléolithique en Gironde in La vie préhistorique[END_REF]; Vaise (Pasty in Treffort dir., 2017) and maybe at La Guichaumerie, in Maine-et-Loire (Naudinot, 2010) and Roquemissou in Aveyron [START_REF] Boboeuf | Le Paléolithique final de la haute vallée de l'Aveyron d'après les stratigraphies du site de Roquemissou (Aveyron). Point et remarques sur les connaissances[END_REF]. In the same time, three sites yielded fragments of long bones that are finely engraved with schematic zoomorphic representations (aurochs or horses), filled in with crosshatching in places. These items have been recorded only in Early Laborian contexts: on the eponymous site (n=1; [START_REF] Coulonges | Magdalénien et périgordien post-glaciaires: la grotte de la Borie del Rey (Lot-et-Garonne)[END_REF], at Le Morin (n=3; [START_REF] Guy | Enquête stylistique sur l'expression figurative épipaléolithique en France: de la forme au concept[END_REF] and at Le Pont d'Ambon (n=23; [START_REF] Paillet | De nouvelles découvertes d'art mobilier laborien dans le Nord du Périgord[END_REF]. The attribution to the Laborian of the child burial of La Madeleine is based on direct 14 C dating (10190 ± 100 BP) and the dorsal decubitus position of the body in a pit filled with ochre -also reminiscent of behavior in the Italian Late Epigravettian [START_REF] Gambier | Datation de vestiges humains présumés du Paléolithique supérieur par la méthode du carbone 14 en spectrométrie de masse par accélérateur[END_REF]. Finally, the Laborian ornament is composed mainly of shells, and more particularly of turritella and dentalium [START_REF] Vanhaeren | La parure de l'enfant de la Madeleine (fouilles Peyrony)[END_REF]; see Chauvière and Rigaud in Langlais et al., 2014b; see Rigaud in [START_REF] Langlais | Le Laborien récent de la grotte-abri de Peyrazet (Creysse, Lot)[END_REF].

Flint hunting points: particular chronocultural and geographic markers

During the Early Laborian, the dominant morphotype is a straight-backed point with a truncated base, the so-called Malaurie point, sometimes associated with backed bitruncated pieces ("rectangles") which may partly correspond to recycling of fractured truncated backed points (Langlais et al., 2014b;fig.2). It should be pointed out that no preferential lateralization of the backs and truncations has been demonstrated on these artifacts (ibid. fig. 23) and that variations in blank dimensions and the care taken with the retouch can be noted from one site to another. If we observe the geographic distribution of the sites that have delivered Malaurie points that can be attributed to the Laborian (fig. 3), we notice a high concentration of sites in the Aquitaine basin and a few others, for the moment, towards the North [START_REF] Fagnart | Les industries lithiques du Paléolithique supérieur dans le Nord de la France[END_REF][START_REF] Valentin | Les groupes humains et leurs traditions au Tardiglaciaire dans le Bassin parisien. Apports de la technologie lithique comparative[END_REF][START_REF] Bodu | Les faciès tardiglaciaires à grandes lames rectilignes et les ensembles à pointes de Malaurie dans le sud du Bassin parisien : quelques réflexions à partir de l'exemple du gisement du Closeau (Hauts-de-Seine)[END_REF][START_REF] Naudinot | La fin du Tardiglaciaire dans le Grand-Ouest de la France[END_REF]Biard and Hinguant dir., 2011) and East [START_REF] Monin | Apport de la technologie lithique à l'étude de séries anciennes. Les assemblages tardiglaciaires des chasseurs de marmottes des grottes de Colomb et de la Passagère à Méaudre (Vercors, Isère)[END_REF][START_REF] Fornage-Bontemps | Le niveau A4 de Rochedane, l'Est de la France et la question des influences épigravettiennes à la fin du Tardiglaciaire[END_REF].

During the Late Laborian, a shift in the lithic content of weaponry can be noticed with the development of two new morphotypes: Blanchères points and bitruncated trapezoids [START_REF] Naudinot | La fin du Tardiglaciaire dans le Grand-Ouest de la France[END_REF]Langlais et al., 2014b;fig.2). It should be pointed out that the apexes of Blanchères points are preferentially lateralized in their proximal part [START_REF] Valentin | Les groupes humains et leurs traditions au Tardiglaciaire dans le Bassin parisien. Apports de la technologie lithique comparative[END_REF]Naudinot, 2010;Langlais et al., 2014b voir fig. 23) while the backs are on the left or the right edge at La Borie del Rey (Langlais et al., op. cit.) and more frequently on the left in the Greater West region (Naudinot, op. cit.). Points with oblique truncation similar to those found at the Le Buhot site in Calleville in Normandy (Biard and Hinguant dir., 2011) are also present at La Fosse in Mayenne and Les Prises in Charentes-Maritimes [START_REF] Naudinot | La fin du Tardiglaciaire dans le Grand-Ouest de la France[END_REF]. At the La Fosse site, alongside the dominant combination of Blanchères points and bitruncated trapezoids, the possible presence of a few tanged pieces with oblique truncation, which also underscore the cultural links with the (Epi)Ahrensburgian [START_REF] Naudinot | Socio-economic organization of Final Paleolithic societies: New perspectives from an aggregation site in Western France[END_REF]. Parallel to the (admittedly discreet) spread of northern morphotypes towards the West, we can thus note the presence of the ideas of the Late Laborian in the North-West of France, with both Blanchères points and bitruncated trapezoids (fig. 3, Jacquier et al., in press). The eastward extension of the latter, thanks to the discovery of the Vaise site (see Pasty in Treffort dir., 2017), offers a new testimony of Late Laborian with bitruncated trapezoids. We can recall the presence of the same morphotypes "bitruncated trapezoids" in Northern Italian Late Epigravettian in early contexts of the Younger Dryas [START_REF] Peresani | Bus de la Lum and the Epigravettian occupation of the Venetian Pre-Alps during the Younger Dryas[END_REF][START_REF] Ferrari | Trapezoids and double truncations in the Epigravettian assemblages of northern-eastern Italy[END_REF][START_REF] Dalmeri | Rise and fall in the utilization of trapézoïdal microlithes during the Late Upper Palaeolithic in Europe. An overview from the Italian record[END_REF]. [START_REF] Champagne | L'abri du Roc d'Abeilles à Calviac (Dordogne)[END_REF]13,18-19,24,25: Peyrazet, drawing S. Ducasse; 14-15: Pont d'Ambon c.2 after [START_REF] Célérier | L'abri sous roche de Pont d'Ambon à Bourdeilles (Dordogne). I. Technologie de l'outillage lithique taillé, II. Inventaire et typométrie des pointes aziliennes[END_REF]16: Le Morin, drawings S. Pasty;17: Rochereil, drawings C. Fat Cheung;20,21,26-28: La Fosse, drawings F. Blanchet after Naudinot, 2013;22,23,29,30: Borie del Rey, drawings C. Fat Cheung). At the eponymous sites, as in several stratified and open-air sites, we should also note the presence of a few backed bitruncated pieces and Malaurie points in a Late Laborian context, and thus associated with the dominant combination of Blanchères points and bitruncated trapezoids. The association of points with concave oblique truncation and Malaurie points at Le Buhot-Locus 2 in Normandy can also be noted (Biard and Hinguant dir., 2011). The question of the continuation of Malaurie points into the Late Laborian remains a subject of discussion, notably in light of the taphonomic context of the records [START_REF] Langlais | Le Laborien récent de la grotte-abri de Peyrazet (Creysse, Lot)[END_REF][START_REF] Langlais | La séquence archéostratigraphique du Cuze de Sainte-Anastasie (Cantal): nouvelle approche des industries lithiques du Paléolithique final au Mésolithique[END_REF].

From a chronological point of view, 14 C AMS dates circumscribe the Laborian in its broadest sense as between 12.5 and 10.8 ka cal BP (Langlais et al., 2014a and[START_REF] Marquebielle | Une rupture dans le travail des matières osseuses entre le Paléolithique final et le Mésolithique? Quelques éléments de reflexion à partir de sites Nord aquitains[END_REF]. Despite the 14 C plateau, on the basis of the small amount of available data, we propose the hypothesis of an Early Laborian corresponding roughly to the second half of the Younger Dryas, and the Late Laborian to the first half of the Preboreal. This transition seems to be centered not around the beginning of the Holocene at 11.7 ka cal BP but around the "11.4 event" recorded in glacial archives [START_REF] Rasmussen | A stratigraphic framework for abrupt climatic changes during the Last Glacial period based on three synchronized Greenland ice-core records: refining and extending the INTIMATE event stratigraphy[END_REF]. However, further dating is necessary to clarify this correlation, as is work on continental records to establish the regional context of this climate event.

A technocomplex of blades and bladelets with flat cross-sections and straight profiles

In the current state of research and analyses of the material, it is difficult (if not impossible) to make a distinction between Early and Late Laborian blade production (Langlais et al., 2014b). For the Early Laborian, the collections of La Borie del Rey (levels 7 and 5 after Coulonges), Rochereil (level II sup.), Port-de-Penne, Le Pont d'Ambon (level 2), Champ-Chalatras and Vaise [START_REF] Pasty | Le gisement épipaléolithique à pointes de Malaurie de Champ Chalatras (Les Martres d'Artière, Puy-de-Dôme[END_REF]Langlais et al., 2014b;see Pasty in Treffort dir., 2017) show a search for broad, regular blades with a flat cross-section and straight profile (fig. 4). These particular blanks are obtained by working the broad face of a block with a soft hammerstone (see below). The same objective was noted earlier and described for the Late Laborian at La Fosse and Le Camp d'Auvours (Naudinot, 2010[START_REF] Naudinot | La fin du Tardiglaciaire dans le Grand-Ouest de la France[END_REF][START_REF] Jacquier | Approche fonctionnelle de l'outillage lithique à l'aube de l'Holocène dans le nord-ouest de la France[END_REF], then at Peyrazet and at Le Cuze de Sainte-Anastasie [START_REF] Langlais | Le Laborien récent de la grotte-abri de Peyrazet (Creysse, Lot)[END_REF][START_REF] Langlais | La séquence archéostratigraphique du Cuze de Sainte-Anastasie (Cantal): nouvelle approche des industries lithiques du Paléolithique final au Mésolithique[END_REF]. Roughly speaking, the blade production scheme presented below and first defined in Western France does correspond to the scheme of the Laborian as a whole. It also shows similarities with what has been described for the Belloisian in the North, although more modest in its dimensions [START_REF] Bodu | L'industrie à pièces mâchurées de Donnemarie-Dontilly (Seine-et-Marne, France): un faciès tardiglaciaire inédit dans le Bassin parisien[END_REF][START_REF] Valentin | Les groupes humains et leurs traditions au Tardiglaciaire dans le Bassin parisien. Apports de la technologie lithique comparative[END_REF][START_REF] Valentin | Jalons pour une paléohistoire des derniers chasseurs (XIVe-VIe millénaire avant J.-C.)[END_REF][START_REF] Biard | Le bivouac préhistorique du Buhot à Calleville (Eure)[END_REF][START_REF] Valentin | Initialisation and progression of the core reduction process at Donnemarie-Dontilly (Seine-et-Marne, France), site of the Belloisian tradition[END_REF][START_REF] Biard | Une occupation temporaire au Belloisien? Le cas du locus 28704 du site d'Alizay (Eure, France)[END_REF]. A new look to these assemblages at light of the results from Western France [START_REF] Naudinot | La fin du Tardiglaciaire dans le Grand-Ouest de la France[END_REF] recently allowed to recognized the search for flat cross section blades as one of the main characteristic of this production [START_REF] Valentin | Initialisation and progression of the core reduction process at Donnemarie-Dontilly (Seine-et-Marne, France), site of the Belloisian tradition[END_REF]. When working on a block or nodule, bifacial shaping from the narrow faces forms regular transverse convexities. It is from one of these anterolateral dihedrals that initialization is performed. The debitage then works progressively into the broad surface from two striking platforms. Progression of blade/bladelet production is marked by regular returns made to one of the anterolateral dihedrals before returning to the wide face, in order to maintain minimal convexity conditions (fig. 5). The core's back is rarely exploited and generally presents transversal negatives, which are the traces of the initial transversal shaping and of reworking by anterolateral neo-crests. Few cases of complete or sub-complete rotating debitage result from a succession of combined sequences. On flakes, debitage begins by more-or-less carefully prepared anterolateral removal, then moves onto the naturally convex lower face. Most of the cores and blades show use of two striking platforms alternating more rapidly in the first laminar sequences than once the volume has been reduced to small blades and bladelets. Use of a soft hammerstone is systematic and accompanied by more or less careful abrasion of the edges of the striking platforms. Continuous reduction of volumes allows to provide blade blanks (tools) and small blades (truncated pieces and Malaurie points/bitruncated pieces). The Late Laborian collections, however, show marked development of a lamellar component, either continuing on from the reduced laminar debitage, or separately from small volumes worked in an identical way or using less productive techniques, such as on a flake edge or from superior face of a thick blade [START_REF] Naudinot | La fin du Tardiglaciaire dans le Grand-Ouest de la France[END_REF]Langlais et al., 2014b[START_REF] Langlais | La séquence archéostratigraphique du Cuze de Sainte-Anastasie (Cantal): nouvelle approche des industries lithiques du Paléolithique final au Mésolithique[END_REF]. The development of bladelets production in the Late Laborian corresponds to the production of Blanchères points. However, these groups did not abandon the production of the small blades preferred during the Early Laborian in favor of Malaurie points and now points with oblique truncation and bitruncated trapezoids. The blades, small blades and bladelets of the Laborian are standardized and have an identical design structured around a straight profile and a flat cross-section. We can recall that the desired blade blanks in the Laborian can be likened to the selected blades described by M. Biard working on collections from Normandy that have been attributed to the Belloisian (Biard and Hinguant dir., 2011;Biard and Valentin, in press). The dominant tool types are made up of truncated pieces, endscrapers, burins and rarely few pieces with bruised edges as at Le Pont d'Ambon c.2. The latter are not unlike the examples from La Fosse or Le Camp d'Auvours [START_REF] Naudinot | La fin du Tardiglaciaire dans le Grand-Ouest de la France[END_REF], the northern Belloisian collections (e.g. [START_REF] Bodu | L'industrie à pièces mâchurées de Donnemarie-Dontilly (Seine-et-Marne, France): un faciès tardiglaciaire inédit dans le Bassin parisien[END_REF][START_REF] Fagnart | Le Paléolithique supérieur récent et final dans le Nord de la France dans son cadre paléoclimatique[END_REF] and the long blades of Great Britain (e.g. [START_REF] Barton | L'Europe centrale et septentrionale au Tardiglaciaire, actes de la table-ronde de Nemours[END_REF]. Leaving aside the question of the use of these pieces with bruised edges (e.g. [START_REF] Fagnart | Fonction des pièces mâchurées du Paléolithique final du Bassin de la somme : caractères tracéologiques et données contextuelles[END_REF][START_REF] Jacquier | Approche fonctionnelle de l'outillage lithique à l'aube de l'Holocène dans le nord-ouest de la France[END_REF], functional studies carried out recently on Laborian assemblages have clearly shown that retouched tools constitute a small proportion of lithic toolkits [START_REF] Jacquier | Approche fonctionnelle de l'outillage lithique à l'aube de l'Holocène dans le nord-ouest de la France[END_REF]. Used artefacts are mainly constituted of unmodified blades (up to 70 % of the total tools excluding projectile points) used for butchering, cutting soft animal tissues, processing hide and secondarily to process plant, bone or mineral materials (Guéret and Jacquier, in press;[START_REF] Jacquier | Analyse fonctionnelle des outillages lithiques et interprétations socioéconomiques du statut des sites tardiglaciaires du Buhot à Calleville (Eure) et de la Fosse à Villiers-Charlemagne (Mayenne)[END_REF][START_REF] Jacquier | Approche fonctionnelle de l'outillage lithique à l'aube de l'Holocène dans le nord-ouest de la France[END_REF][START_REF] Jacquier | Socio economic significance of stone tools recycling, reuse and maintenance at the end of the Lateglacial in Northwestern France[END_REF]; see Jacquier in [START_REF] Langlais | Le Laborien récent de la grotte-abri de Peyrazet (Creysse, Lot)[END_REF]2018;fig.6); the more regular blanks being generally recycled by retouch (end scrapers and burins) after a first valuation of the cutting edges. This need for knives and unmodified cutting edges as well as the nature of the material being currently processed (essentially soft materials; plant and bone processing being scarce) appears particularly coherent with the search for flat and straight blades. It might even be tempting to propose a causal relationship between the needs of cutting edges and the Laborian debitage scheme. However, this need for unmodified cutting edges remains broadly unchanged during the Early Mesolithic (Guéret 2013, 2017, Guéret andJacquier in press) despite a much more simple and flexible debitage scheme. Fig. 6: Examples of knives on blades from Early Laborian at Port-de-Penne (CAO J. Jacquier) From the techno-economic point of view, this search for normalized, specific blanks requires flints of high clastic quality. During the Early and Late Laborian, we therefore see a renewal of raw material sourcing networks compared to the Late Azilian which was less demanding in techno-economic terms (Naudinot, 2010[START_REF] Naudinot | Anticiper ou s'adapter? Acquisition des matériaux au Tardiglaciaire dans le Massif armoricain[END_REF][START_REF] Cheung | Comparaison des séquences aziliennes entre Dordogne et Pyrénées: état des travaux en cours[END_REF]Fat Cheung, 2015). In regions with low lithic availability (the Armorican Massif, Central Massif and Pyrenees notably), importations of blocks transported over great distances (> 200 km, Fig. 5 n°2) were not rare. More generally, we can note transportation of flint blades, often over distances of several hundred miles [START_REF] Pasty | Le gisement épipaléolithique à pointes de Malaurie de Champ Chalatras (Les Martres d'Artière, Puy-de-Dôme[END_REF][START_REF] Naudinot | Anticiper ou s'adapter? Acquisition des matériaux au Tardiglaciaire dans le Massif armoricain[END_REF][START_REF] Naudinot | Socio-economic organization of Final Paleolithic societies: New perspectives from an aggregation site in Western France[END_REF]Langlais et al., 2014b[START_REF] Langlais | Le Laborien récent de la grotte-abri de Peyrazet (Creysse, Lot)[END_REF][START_REF] Jacquier | Approche fonctionnelle de l'outillage lithique à l'aube de l'Holocène dans le nord-ouest de la France[END_REF][START_REF] Langlais | La séquence archéostratigraphique du Cuze de Sainte-Anastasie (Cantal): nouvelle approche des industries lithiques du Paléolithique final au Mésolithique[END_REF].

Discussion and Conclusion

The research conducted in recent years on various projects has provided a more precise image of the Laborian. The proposal of two phases -Early and Late -enables us, on the basis of the lithic weaponry, to extend its diffusion area northwards towards so-called "Belloisian areas" at the interface with Epiahrensburgian territories in particular. The discovery of new sites, such as Vaise in Lyon (see Pasty in Jallet andBouvier dir., 2012 andTreffort dir., 2017;Langlais et al., in press) also offers new insights into the interactions during the Recent Laborian. We thus see a genuine cultural melting pot taking shape in Western Europe, the main vectors of which are hunting weapon elements and an original concept of blade production. Many studies of industries with flat and straight blades/bladelets (sic.) once again highlight the obvious cultural links between Laborian and Belloisian technologies (if the latter can be said to have a cultural or more strictly economic value, [START_REF] Valentin | Jalons pour une paléohistoire des derniers chasseurs (XIVe-VIe millénaire avant J.-C.)[END_REF][START_REF] Fagnart | Les industries à grandes lames et éléments mâchurés du Paléolithique final du nord de la France : une spécialisation fonctionnelle des sites épi-ahrensbourgiens[END_REF][START_REF] Naudinot | La fin du Tardiglaciaire dans le Grand-Ouest de la France[END_REF]. Hunting weapon elements, perforating and cutting points of Laborian hunters, thus seems to testify to interactions with groups from the Epiahrensburgian (tanged points or with oblique truncation) and also the Epigravettian (bitruncated trapezoids). Laborian bone equipment, although admittedly little known for the moment, does present key features that should now be searched for more keenly, such as barbed points (see above, with Le Pont d'Ambon and Gouërris), the aim now being to understand any possible affiliation with Azilian production [START_REF] Marquebielle | Une rupture dans le travail des matières osseuses entre le Paléolithique final et le Mésolithique? Quelques éléments de reflexion à partir de sites Nord aquitains[END_REF]. The same thing applies to the presence of pebbles with geometric engravings in several Early sites, while others set themselves apart within the region (on the basis of current discoveries) with original zoomorphic art on bone. The resumption of excavations of La Borie del Rey (Langlais and Mallye, directors) and Malaurie (Laroulandie and Langlais, directors) will undoubtedly allow us to advance our understanding of this newly described synchronic and diachronic cultural variability within the Laborian.

Fig. 1 :

 1 Fig.1: Principal prey species for sites of Early and Late Laborian.

Fig. 2 :

 2 Fig.2: Main component of lithic weaponry of Early and Late Laborian (1-17: Malaurie points and backed bitruncation, 18-23: Blanchères points, 24-30: bitruncated trapezoids; 1-9: La Borie del Rey, after Le Tensorer, 1981; 10-11: Port-de-Penne, after Detrain et al., 2018; 12: Roc d'Abeilles after[START_REF] Champagne | L'abri du Roc d'Abeilles à Calviac (Dordogne)[END_REF] 13,18-19,24,25: Peyrazet, drawing S. Ducasse; 14-15: Pont d'Ambon c.2 after Célérier, 1993; 16: Le Morin, drawings S. Pasty; 17: Rochereil, drawings C. Fat Cheung; 20,21,26-28: La Fosse, drawings F. Blanchet after Naudinot, 2013; 22,23,29,30: Borie del Rey, drawings C. Fat Cheung).

Fig. 3 :

 3 Fig.3: Location of main lithic weaponry from Laborian (purple : Malaurie Points ; red : Blanchères Points ; Orange : Trapeziform bitruncations) ; CAD ML.

Fig. 4 :

 4 Fig. 4: Examples of desired Laborian Blades (1-3: Rochereil, drawings G. Devilder; 4: Champ Chalatras, drawings P. Alix after Pasty et al., 2002; 5-6: La Borie del Rey, drawings C. Fat Cheung; 7-8: Port-de-Penne, drawings C. Fat Cheung).

Fig. 5 :

 5 Fig.5: Examples of Blades Laborian Cores (large face with antero-latéral maintenance; 1 : La Borie del Rey; 2: Port-de-Penne ; drawings C. Fat Cheung).

Table 1 :

 1 List of sites depicted in figure3.

Acknowledgements

This work was carried out in collaboration with the DRAC (Regional Directorate for Cultural Affairs) of Nouvelle Aquitaine and of Occitanie, in particular their respective Regional Archaeology Services, and Departmental Councils of Lot-et-Garonne and Lot. Many thanks to the Archéologies association, to V. Mistrot (Musée d'Aquitaine de Bordeaux), J.-J. Cleyet-Merle (Musée National de Préhistoire des Eyzies-de-Tayac), C. Schwab (Musée d'Archéologie Nationale de Saint-Germain-en-Laye) and P. Paillet (MNHN / Musée de l'Homme Paris) for facilitating access to the collections for us. Thanks to Natasha Reynolds for the review of English.