Foraging behaviour and time allocation of chick-rearing Razorbills Alca torda at Graesholmen, central Baltic Sea
Foraging behaviour and time allocation of chick-rearing Razorbills Alca torda at Graesholmen, central Baltic Sea
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DOI：
10.1111/j.1474-919x.2001.tb04941.x
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发表时间：
2001-07-01
期刊：
影响因子：
2.1
通讯作者：
Lyngs, P
中科院分区：
文献类型：
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作者：
Benvenuti, S;Dall'Antonia, L;Lyngs, P
一种新型鸟载数据记录仪可以按照预设的时间间隔存储来自飞行和深度传感器的数据，用于研究在 Graesholmen（丹麦波罗的海中部）岛上繁殖的小剃刀鹬 Alca tarda 的觅食模式和潜水行为。这些仪器记录了六只不同鸟类完成的 35 次觅食行程中的所有相关事件；第七只鸟配备了方向记录器，提供了七次不同旅行中表现出的方向偏好信息。一次觅食之旅通常由多次飞行组成，期间可能会进行少量潜水，以探索该地点是否有猎物。真正的觅食发生在出境旅行的最后一站，之后鸟儿通过一次或连续几次飞行返回巢穴。夜间旅行的持续时间明显长于白天的旅行，这可能是由于鸟类在不在巢中“执勤”时表现出对熟悉的海洋环境的偏好。大多数潜水都是 V 形潜水，鸟类下降到最大深度，然后开始上升。记录了潜水深度的明显日变化，从未超过 43 m。我们的结果表明，新型记录设备可用于回答有关海鸟觅食策略的基本问题。
A new type of bird-borne data logger, which stores data from flight and depth sensors at pre-set intervals, was used to investigate the foraging pattern and diving behaviour of chick-rearing Razorbills Alca tarda breeding on the islet of Graesholmen (central Baltic Sea, Denmark). The instruments recorded all relevant events in the 35 foraging trips accomplished by six different individual birds; a seventh bird, equipped with a direction recorder, provided information on directional preferences exhibited on seven different trips. A foraging trip usually consisted of a number of flights interrupted by a small number of dives probably performed to explore the site for prey availability. True foraging occurred during the last stops in the outbound trip, after which the bird returned to the nest with a single flight or a sequence of a few flights. The duration of nocturnal trips was significantly longer than diurnal trips, possibly due to a preference for the familiar marine environment shown by birds when they are not 'on duty' in the nest. The majority of dives consisted of V-shaped dives in which birds descend to a maximum depth and then start ascending. A clear diurnal variation of the dive depth, which never exceeded 43 m, was recorded. Our results show that the new types of recording devices can be used to answer basic questions about the foraging strategies of marine birds.