TY  - STD
AU  - Antoine, A.
PY  - 2022//
TI  - Beneath the Antarctic sea-ice: Fine-scale analysis of Weddell seal (Leptonychotes weddellii, Lesson 1826) behaviour and predator prey interactions, using micro-sonar data and video recordings in Terre Adélie
N2  - The sea-ice zone constitutes the breeding and foraging habitat of large populations of ice-based species,&nbsp;pointing at its far-reaching ecological importance. Given its sensitivity to global warming, there is an&nbsp;urgent need for determining how predators use their environment, to understand and predict their response&nbsp;to climate variability. New perspectives are offered by miniature animal-borne sensors: in 2019, 3 sonar&nbsp;tags were deployed on lactating female Weddell seals for 7 days in Terre Ad&eacute;lie to study 3D animal&nbsp;movement and fine-scale predator-prey interactions. Lactating females demonstrated central-place foraging&nbsp;strategy, with restricted foraging area (3-6 km) and mostly benthic dives (97% of dives, visualising the&nbsp;seafloor on echograms). Their foraging effort was constrained by the presence of their pup: females spent&nbsp;most of their time hauling out (77% of overall recordings). The time spent underwater was mostly&nbsp;dedicated to diving (&gt;5m) (1.36 on 7days, 854 dives recorded), as opposed to shallower under ice activities&nbsp;(&lt;5m) (0.3 days). A total of 331 prey capture attempts (PrCA) were recorded, using tri-axial acceleration&nbsp;data, of which 125 prey (4.7 &plusmn; 1.5 cm on average) were identified by the sonar on 78 dives (4.24 &plusmn; 3.99&nbsp;PrCA/dive). All PCA occur on the seafloor, at shallower depth than usual Weddell seal records (88 &plusmn; 30 m).&nbsp;Lactation is therefore a period of physiological stress, with foraging limited by pup compared with other&nbsp;parts of the life cycle. Using functional principal component analysis and model-based clustering on high&nbsp;resolution dive data, we found that PrCAs occur mostly in 2 of the 5 dive shape clusters. Foraging dives are&nbsp;characterised by W or V shape and high sinuosity, at the scale of the dive (W shapes) or during the ascent&nbsp;phase (V shapes). During the approach phase, seals constantly scan the area by regularly moving their head&nbsp;left to right, suggesting opportunistic behaviour. Shallow phase behaviour was studied using video&nbsp;recordings (2h recorded per seal). Seals spent most of their time interacting with their pup (33%) and<br />hauling-out (42%). Most mother-pup interactions were on sea-ice (71%), as opposed to underwater&nbsp;(29%). The results suggest lactating females&rsquo; energy budget changes, with lactation being a period of&nbsp;physiological stress. This period of feeding pressure might put them at higher risk regarding adaptation to&nbsp;environmental variability.
N1  - exported from refbase (http://publi.ipev.fr/polar_references/show.php?record=8747), last updated on Sat, 29 Jun 2024 09:59:14 +0200
ID  - Antoine2022
ER  -