Year-round movements of white-chinned petrels from Marion Island, south-western Indian Ocean

• Published in: Antarctic Science
• Main Authors: Rollinson, Dominic P., Dilley, Ben J., Davies, Delia, Ryan, Peter G.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 2018
• Subjects: Geology; Ecology, Evolution, Behavior and Systematics; Oceanography; Antarctic; Indian; New Zealand; Antarc*; Antarctic Science; Antarctica; Marion Island; Prince Edward Islands
• Online Access: http://dx.doi.org/10.1017/s0954102018000056; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0954102018000056

Abstract White-chinned petrels Procellaria aequinoctialis L. are the most frequently recorded procellariiform species in the bycatch of Southern Hemisphere longline fisheries. Our study investigated the year-round movements of ten adult white-chinned petrels (seven breeders, three non-breeders/suspected pre-breeders) from Marion Island tracked with global location sensor (GLS) loggers for three years. Additionally, 20 global positioning system (GPS) tracks were obtained from breeding white-chinned petrels during incubation ( n =9) and chick-rearing ( n =11). All GLS-tagged birds remained, year-round, in the area between southern Africa and Antarctica, not making any major east/west movements. Three core areas (50% kernels) were utilized: around the Prince Edward Islands (PEI; incubation and early chick-rearing), c . 1000 km west of PEI (pre-breeding and early incubation) and around South Africa (non-breeding birds). The only area where 50% utilization kernels overlapped with intensive longline fishing effort was off the Agulhas Bank (non-breeding season). Our results confirm the lack of foraging overlap between the two subspecies; nominate birds (South Georgia/south-western Indian Ocean) utilize separate areas to P. a. steadi (New Zealand/sub-Antarctic islands), and thus should be treated as separate management units. Knowledge of the year-round movements of a vagile species, such as the white-chinned petrel, is important for its continued conservation.