RT Journal Article
SR Electronic
T1 Sex-specific variation in the use of vertical habitat by a resident Antarctic top predator
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2020.06.15.152009
DO 10.1101/2020.06.15.152009
A1 Theoni Photopoulou
A1 Karine Heerah
A1 Jennifer Pohle
A1 Lars Boehme
YR 2020
UL http://biorxiv.org/content/early/2020/06/26/2020.06.15.152009.abstract
AB Patterns of habitat use are commonly studied in horizontal space, but this does not capture the four-dimensional nature of ocean habitats. There is strong seasonal variation in vertical ocean structuring, particularly at the poles, and deep-diving marine animals encounter a range of oceanographic conditions. We use hidden Markov models fitted to telemetry data from an air-breathing top predator to identify different diving behaviours and understand usage patterns of vertically distributed habitat. We show that preference for oceanographic conditions in the Weddell Sea, Antarctica, varies by sex in Weddell seals, and present the first evidence that both sexes use high-density, continental shelf water masses. Males spend more time in the colder, unique high-salinity shelf water masses found at depth, while females also venture off the continental shelf and visit warmer, shallower pelagic water masses. Both sexes exhibit a diurnal pattern in diving behaviour that persists from austral autumn into winter. These findings provide insights into the Weddell Sea shelf and open ocean ecosystem from a top predator perspective. The differences in habitat use in a resident, sexually monomorphic Antarctic top predator suggest a different set of needs and constraints operating at the intraspecific level, which are not driven by body size.Competing Interest StatementThe authors have declared no competing interest.