Different habitat use strategies by subadult and adult ringed seals (Phoca hispida) in the Bering and Chukchi seas

作者：Crawford Justin A^*; Frost Kathryn J; Quakenbush Lori T; Whiting Alex

来源：Polar Biology, 2012, 35(2): 241-255.

DOI：10.1007/s00300-011-1067-1

• Ringed seals
• Phoca hispida
• Movements
• Habitat use
• Sea ice

Habitat partitioning by adult and subadult ringed seals (Phoca hispida) is poorly understood. Conclusions about displacement of subadult seals to suboptimal offshore habitat are largely based on nearshore observations as few satellite tagging studies include data from winter months. In this study, movement patterns of 14 subadult and 11 adult ringed seals were monitored in the Bering and Chukchi seas using satellite-linked telemetry. Seals were captured in Kotzebue Sound, Alaska, during October 2007 and 2008 and tracked for 17-297 days. Subadult ringed seals traveled south from the Chukchi Sea into the Bering Sea ((x) over bar = 36 km/day) as sea ice coverage increased during November and December, remained similar to 1,000 km south near the ice edge during winter and returned north in the spring with the receding ice edge. Adults remained in the Chukchi and northern Bering seas, where their movements were more localized ((x) over bar = 22 km/day). Adults were on average 322 km farther from the ice edge and 48 km closer to land and shorefast ice than were subadults. During winter, adult ringed seals construct and maintain breathing holes through the ice, and in spring, females give birth in subnivean lairs, mostly in shorefast ice; adult males defend breeding territories around those lairs. Our results show that subadult ringed seals, unconstrained by the need to maintain territories that contain stable breeding/pupping habitat, moved south to the Bering Sea ice edge, where there are better feeding opportunities, lower energetic costs (no breathing hole maintenance), and less exposure to predation.

• 出版日期2012-2