title: Predictions replaced by facts: a keystone species' behavioural responses to declining arctic sea-ice.
abstract: Since the first documentation of climate-warming induced declines in arctic sea-ice, predictions have been made regarding the expected negative consequences for endemic marine mammals. But, several decades later, little hard evidence exists regarding the responses of these animals to the ongoing environmental changes. Herein, we report the first empirical evidence of a dramatic shift in movement patterns and foraging behaviour of the arctic endemic ringed seal (Pusa hispida), before and after a major collapse in sea-ice in Svalbard, Norway. Among other changes to the ice-regime, this collapse shifted the summer position of the marginal ice zone from over the continental shelf, northward to the deep Arctic Ocean Basin. Following this change, which is thought to be a 'tipping point', subadult ringed seals swam greater distances, showed less area-restricted search behaviour, dived for longer periods, exhibited shorter surface intervals, rested less on sea-ice and did less diving directly beneath the ice during post-moulting foraging excursions. In combination, these behavioural changes suggest increased foraging effort and thus also likely increases in the energetic costs of finding food. Continued declines in sea-ice are likely to result in distributional changes, range reductions and population declines in this keystone arctic species.
authors.affiliation: Norwegian Polar Institute, Fram Centre, Tromsø 9296, Norway Department of Arctic and Marine Biology, Arctic University of Norway, Tromsø 9037, Norway.
authors.forename: Charmain D
authors.initials: CD
authors.lastname: Hamilton
authors.affiliation: Norwegian Polar Institute, Fram Centre, Tromsø 9296, Norway.
authors.forename: Christian
authors.initials: C
authors.lastname: Lydersen
authors.affiliation: Department of Arctic and Marine Biology, Arctic University of Norway, Tromsø 9037, Norway.
authors.forename: Rolf A
authors.initials: RA
authors.lastname: Ims
authors.affiliation: Norwegian Polar Institute, Fram Centre, Tromsø 9296, Norway kit.kovacs@npolar.no.
authors.forename: Kit M
authors.initials: KM
authors.lastname: Kovacs
mesh_terms: D000818:Animals; D001070:Appetitive Behavior; D001110:Arctic Regions; D057231:Climate Change; D004242:Diving; D017753:Ecosystem; D005260:Female; D046448:Ice Cover; D008297:Male; D046048:Seals, Earless / Q000502:physiology*; D013538:Svalbard; D013550:Swimming; D013686:Telemetry
keywords: Pusa hispida; climate change; polar; ringed seal; sympagic community