Foraging strategies of the black-legged kittiwake Rissa tridactyla at a North Sea colony:: evidence for a maximum foraging range
Foraging strategies of the black-legged kittiwake Rissa tridactyla at a North Sea colony:: evidence for a maximum foraging range
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DOI：
10.3354/meps245239
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发表时间：
2002-01-01
影响因子：
2.5
通讯作者：
Wanless, S
中科院分区：
文献类型：
--
作者：
Daunt, F;Benvenuti, S;Wanless, S
苏格兰东南部五月岛上的黑腿三趾鸥里萨（Rissa）主要以较小的沙笛鱼（Ammodytes marinus）为食，这是一种丰富的中上层鱼类，目前是北海最大的渔业。五月岛上的黑腿三趾鸥数量正在下降，渔业也受到了牵连。为了评估这一问题，迫切需要提高我们对影响黑腿三趾鸥觅食行为的因素的理解。在1999年，我们进行了一个详细的研究觅食策略的黑腿三趾鸥使用特制的活动记录器，使我们能够区分4个关键行为：旅行飞行，觅食飞行，在海面上的存在和出席在巢。我们利用这些数据对海上时间分配的两个关键方面进行了建模：（1）旅行时间和旅行持续时间之间的关系，以及（2）在觅食地积极觅食的时间与海面上不活动时间的比率。我们发现，一个平坦的渐近线的断棒模型是最适合的旅行时间和行程持续时间之间的关系。使用公布的飞行速度为这个物种，我们计算出繁殖黑腿三趾鸥在五月岛的最大范围为73 +/- 9公里，从殖民地。我们推测，这个上限是由猎物的分布，而不是任何精力充沛的飞行成本的限制：一个大的沙洲复杂，已知有高浓度的小沙，完全在这个范围内。有没有一致的模式中的比例的活跃到不活跃的组件的觅食之旅，这表明该物种具有高度灵活的觅食策略在海上，可能反映了不规则的和不可预测的分布和可用性的猎物。我们的研究结果表明，这些鸟类在同一时间和同一地区以Sandeel渔业的作业为食。
Black-legged kittiwakes Rissa tridactyla on the Isle of May, southeast Scotland, feed predominantly on the lesser sandeel Ammodytes marinus, an abundant, pelagic fish that is currently the subject of the largest fishery in the North Sea. The population of black-legged kittiwakes on the Isle of May is declining, and the fishery has been implicated. In order to assess this concern, there is an urgent need to improve our understanding of the factors that affect black-legged kittiwake foraging behaviour. During 1999, we carried out a detailed study of the foraging strategies of black-legged kittiwakes using purpose-built activity loggers that allowed us to distinguish 4 key behaviours: travelling flight, foraging flight, presence on the sea surface and attendance at the nest. We used the data to model 2 key aspects of time allocation at sea: (1) the relationship between the travelling time and trip duration and (2) the ratio of time spent actively foraging to time of inactivity on the sea surface at the foraging grounds. We found that a broken-stick model with a flat asymptote was the best fit for the relationship between travelling time and trip duration. Using published flight speeds for this species, we calculate that breeding black-legged kittiwakes on the Isle of May had a maximum range of 73 +/- 9 km from the colony. We speculate that this upper limit is dictated by the distribution of prey rather than any energetic constraint on flight costs: a large sand bank complex, known to have high concentrations of lesser sandeels, lies entirely within this range. There was no consistent pattern in the ratio of the active to inactive components of the foraging trip, suggesting that this species exhibits highly flexible foraging strategies at sea, probably reflecting the patchy and unpredictable distribution and availability of its prey. Our findings suggest that the birds are feeding on sandeels at the same time and in the same area as the operations of the sandeel fishery.