Use of glacial and terrestrial habitats by harbor seals in Glacier Bay, Alaska: costs and benefits
Use of glacial and terrestrial habitats by harbor seals in Glacier Bay, Alaska: costs and benefits
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DOI：
10.3354/meps09073
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发表时间：
2011-01-01
影响因子：
2.5
通讯作者：
Herreman, Jason K.
中科院分区：
文献类型：
--
作者：
Blundell, Gail M.;Womble, Jamie N.;Herreman, Jason K.
在鳍足类动物中，斑海豹的分布最广（在太平洋和大西洋地区的纬度分别为34至50），栖息地多种多样。美国阿拉斯加的斑海豹在许多方面与北极的鳍足类动物相似，它们依靠冰川的冰来产卵、交配和换毛。正如气候变化影响北极海冰一样，阿拉斯加的潮汐冰川正在迅速消退，减少了海豹的海冰供应。随着气候变化的影响持续，对冰川海豹与陆地海豹的进一步了解可能会揭示对海豹和北极鳍足类动物保护的重要信息。我们比较了在阿拉斯加冰川湾冰川和陆地捕获的海豹的觅食距离、活动预算、饮食和身体状况。在冰川上觅食的海豹的觅食策略和活动预算与在陆地上觅食的海豹有很大的不同。冰川海豹去觅食的路程远得多（>= 40 vs. = 0.09），这表明冰川海豹长途觅食的成本可能会被获得更高质量的远洋鱼类食物所抵消，这可能会让海豹花更多的时间去打捞。在短暂的哺乳期，拖出更多的时间可以有更多的时间将能量从成年雌性转移到依赖的后代。
Among pinnipeds, harbor seals Phoca vitulina have the broadest distribution (a 34 to 50 range in latitudes in the Pacific and Atlantic regions, respectively) and are found in a diversity of habitats. Harbor seals in Alaska, USA, similar to Arctic pinnipeds in many respects, rely upon glacial ice for pupping, mating, and molting. Just as climate change affects Arctic sea ice, tidewater glaciers are rapidly retreating in Alaska, reducing ice availability for harbor seals. An increased understanding of glacial vs. terrestrial harbor seals may reveal information important to conservation of harbor seals and Arctic pinnipeds, as effects of climate change continue. We compared foraging distances, activity budgets, diet, and body condition for seals captured at glacial and terrestrial sites in Glacier Bay, Alaska. Foraging strategies and activity budgets of seals using glacial ice differed substantially from seals using terrestrial sites. Glacial seals traveled significantly farther to forage (>= 40 vs. = 0.09) and suggests that costs of longer foraging trips for glacial seals may be offset by obtaining higher quality diets of pelagic fishes, which may allow seals to spend more time hauled out. During the brief lactation period, more time hauled out could result in more time available for the transfer of energy from adult females to dependent offspring.