Divoky G J, Douglas D C, Stenhouse I J
Friends of Cooper Island, 652 32nd Avenue E, Seattle, WA 98112, USA
US Geological Survey Alaska Science Center, 250 Egan Drive, Juneau, AK, USA.
Biol Lett. 2016 Sep;12(9). doi: 10.1098/rsbl.2016.0275.
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.
曼氏黑海鸠（Cepphus grylle mandtii）是少数全年都与北极海冰相关的海鸟之一，而北极海冰这一栖息地正在迅速变化。夏季海冰面积近期的减少降低了阿拉斯加北极地区该物种的繁殖成功率和种群规模。对于该物种在长达九个月的非繁殖期（9月至次年5月）的活动和分布情况，人们了解甚少，而在此期间海冰范围和构成也在发生变化，且预计还会持续。为了研究鸟类的活动以及海冰在曼氏黑海鸠非繁殖期所起的季节性作用，我们于2011年至2015年期间在阿拉斯加北极地区的一个繁殖地给45只个体部署并回收了地理定位器。黑海鸠在繁殖后立即向北移动到波弗特海和楚科奇海的边缘冰区（MIZ），12月结冰期时向南移动到白令海，并于1月至4月在白令海越冬。大多数鸟类栖息在海冰浓度平均为30%至60%的边缘冰区，季节性变化很小。鸟类全年都经常在冰上栖息，平均每天5小时，主要是在夜间。通过利用边缘冰区及其栖息机会和相关猎物，黑海鸠在冬季沿海海域完全被冰覆盖时仍能留在北极地区。
