The foraging decisions of a central place foraging seabird in response to fluctuations in local prey conditions
The foraging decisions of a central place foraging seabird in response to fluctuations in local prey conditions
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DOI：
10.1111/j.1469-7998.2009.00584.x
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发表时间：
2009-08-01
影响因子：
2
通讯作者：
Montevecchi, W. A.
中科院分区：
文献类型：
--
作者：
Burke, C. M.;Montevecchi, W. A.
在繁殖过程中，海鸟需要平衡的自我和后代供应的限制内的中央地方觅食的需求。为了评估这些限制的行为调整和耐受性，我们研究了常见的海鸠（也被称为常见的海鸠）Uria aalge的喂养策略和繁殖成功，在他们最大和最离岸的殖民地（芬克岛），父母长途跋涉，提供一个单一的毛鳞鱼毛桐给他们的小鸡。我们评估的距离murres从殖民地，其附近的觅食地点和猎物大小的选择在连续两年的毛鳞鱼表现出一个数量级的密度下降和转移从聚集（2004年）分散（2005年）分布的变化。当毛鳞鱼的可用性低（2005年），父母murres增加了35%（60至81公里）的最大觅食距离，并提供了显着较大的毛鳞鱼小鸡，预测的中心位置觅食理论。在这两年中，Murres相对于小毛鳞鱼（100-140 mm）更喜欢大（> 140 mm），但出乎意料的是，随着大毛鳞鱼的相对密度降低，这种偏好增加。我们的结论是，单一的猎物加载穆尔目标较大的毛鳞鱼在长期的觅食之旅的父母是“被迫”选择最好的猎物为他们的后代。低初出茅庐的群众也表明，增加觅食时间时，毛鳞鱼是稀缺的可能会在成本的小鸡（即每天少餐）。在这个殖民地的Murres可能会发挥作用的生理极限以上，进一步或持续的调整觅食努力可能会损害这长寿的海鸟一生的繁殖成功。
During reproduction, seabirds need to balance the demands of self- and offspring-provisioning within the constraints imposed by central place foraging. To assess behavioral adjustments and tolerances to these constraints, we studied the feeding tactics and reproductive success of common murres (also known as common guillemots) Uria aalge, at their largest and most offshore colony (Funk Island) where parents travel long distances to deliver a single capelin Mallotus villosus to their chicks. We assessed changes in the distance murres traveled from the colony, their proximate foraging locations and prey size choice during two successive years in which capelin exhibited an order of magnitude decrease in density and a shift from aggregated (2004) to dispersed (2005) distributions. When capelin availability was low (2005), parental murres increased their maximum foraging distances by 35% (60 to 81 km) and delivered significantly larger capelin to chicks, as predicted by central place foraging theory. Murres preferred large (> 140 mm) relative to small capelin (100-140 mm) in both years, but unexpectedly this preference increased as the relative density of large capelin decreased. We conclude that single prey-loading murres target larger capelin during long foraging trips as parents are 'forced' to select the best prey for their offspring. Low fledgling masses suggest also that increased foraging time when capelin is scarce may come at a cost to the chicks (i.e. fewer meals per day). Murres at this colony may be functioning near physiological limits above which further or sustained adjustments in foraging effort could compromise the life-time reproductive success of this long-lived seabird.