Arctic sea ice a major determinant in Mandt's black guillemot movement and distribution during non-breeding season.
Mandt's black guillemot (Cepphus grylle mandtii) is one of the few seabirds associated in all seasons with Arctic sea ice, a habitat that is changing rapidly. Recent decreases in summer ice have reduced breeding success and colony size of this species in Arctic Alaska. Little is known about the species' movements and distribution during the nine month non-breeding period (September-May), when changes in sea ice extent and composition are also occurring and predicted to continue. To examine bird movements and the seasonal role of sea ice to non-breeding Mandt's black guillemots, we deployed and recovered (n = 45) geolocators on individuals at a breeding colony in Arctic Alaska during 2011-2015. Black guillemots moved north to the marginal ice zone (MIZ) in the Beaufort and Chukchi seas immediately after breeding, moved south to the Bering Sea during freeze-up in December, and wintered in the Bering Sea January-April. Most birds occupied the MIZ in regions averaging 30-60% sea ice concentration, with little seasonal variation. Birds regularly roosted on ice in all seasons averaging 5 h d(-1), primarily at night. By using the MIZ, with its roosting opportunities and associated prey, black guillemots can remain in the Arctic during winter when littoral waters are completely covered by ice.
Friends of Cooper Island, 652 32nd Avenue E, Seattle, WA 98112, USA divoky@cooperisland.org.
G J
0000-0001-9902-8203
GJ
Divoky
US Geological Survey Alaska Science Center, 250 Egan Drive, Juneau, AK, USA.
D C
0000-0003-0186-1104
DC
Douglas
Biodiversity Research Institute, 276 Canco Road, Portland, ME 04103, USA.
I J
0000-0003-3614-9862
IJ
Stenhouse
D000413:Alaska; D025041:Animal Migration / Q000502:physiology*; D000818:Animals; D001110:Arctic Regions; D046091:Charadriiformes / Q000502:physiology*; D057231:Climate Change; D017753:Ecosystem; D046448:Ice Cover
Arctic; black guillemot; geolocation; sea ice; seabird