Consistency in migration strategies and habitat preferences of brown skuas over two winters, a decade apart ...

• Main Authors: Carneiro, APB, Manica, A, Clay, TA, Silk, JRD, King, M, Phillips, RA
• Format: Article in Journal/Newspaper
• Language: English
• Published: Inter-Research Science 2016
• Subjects: Annual variability; Biologging; GAMs; Geolocation; GLS; Habitat selection; Modelling; Seabird; Antarc*; antarcticus; Stercorarius antarcticus
• Online Access: https://dx.doi.org/10.17863/cam.11130; https://www.repository.cam.ac.uk/handle/1810/266351

At-sea movements and activity patterns of brown skuas Stercorarius antarcticus lonnbergi from South Georgia were analysed in 2 winters, a decade apart, to examine the degree of consistency in migration strategies and habitat preferences during the non-breeding and pre-laying exodus periods. Oceanographic habitat preferences of tracked skuas were determined using a robust model accounting for availability. At the population level, brown skuas were broadly consistent in their choice of wintering areas and habitat preferences, although the distribution extended farther east in 2012 than in 2002. Skuas preferred areas associated with static oceanography (bathymetric features) both during the non-breeding and pre-laying periods, which may explain the consistency between years in habitat use. There was no significant effect of year on departure dates from South Georgia, but birds returned earlier to the colony in 2002. Migration schedules varied according to breeding status, with failed birds departing earlier ...