Factors influencing the winter haulout behaviour of Weddell seals: consequences for satellite telemetry

• Published in: Endangered Species Research
• Main Authors: Andrews-Goff, V, Hindell, MA, Field, IC, Wheatley, KE, Charrassin, JB
• Format: Article in Journal/Newspaper
• Language: English
• Published: Inter-Research 2010
• Subjects: Biological Sciences; Ecology; Marine and Estuarine Ecology (incl. Marine Ichthyology); Austral; Weddell; Antarc*; Antarctica; Leptonychotes weddelli; Weddell Seals
• Online Access: http://www.int-res.com/abstracts/esr/v10/p83-92/; https://doi.org/10.3354/esr00257; http://ecite.utas.edu.au/66356

An understanding of pinniped haulout behaviour can provide information on how animalsinteract with their environment, their foraging strategies and the behaviour of their prey. ForWeddell seals Leptonychotes weddelli, knowledge of haulout patterns and the environmental driversof haulout is comprehensive for the austral spring and summer, but is poorly described outside thisperiod. Pinniped behaviour is commonly examined using satellite telemetry; however, it is unclearwhether the behavioural state of the seal can itself influence data acquisition. We examined hauloutbehaviour of female Weddell seals in eastern Antarctica over 3 winters (March to August, 20062008)using satellite-linked data loggers. Haulout behaviour followed a diel cycle with predominantly nocturnalhaulouts. The environmental variables wind speed and temperature were influential onhaulout, with seals tending to haul out more in lower winds and at higher temperatures. Hauloutduration decreased across the winter, as did the number of satellite uplinks, suggesting that hauloutduration played a role in data acquisition. There was no evidence of a decline in tag condition overthis period, indicating that the decrease in uplinks was primarily the result of the winter behaviour ofthe seals. Overall, the number of haulout locations in the data set was over-represented, with moreuplinks per hour occurring when the seals were hauled out than when they were at sea. For Weddellseals and other ice seals, tracking data that include haulout locations can bias spatial representationsof foraging behaviour (e.g. haulout sites may be mistaken for regions of area-restricted search).