The behaviour of seabirds foraging at fishing boats around Shetland
The behaviour of seabirds foraging at fishing boats around Shetland
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海鸟在设得兰群岛周围渔船上觅食的行为
DOI：
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发表时间：
2008
期刊：
影响因子：
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通讯作者：
R. Furness
中科院分区：
文献类型：
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作者：
A. Hudson;R. Furness
在设得兰周围不同类型的渔船中，白鱼拖网吸引了最多的食腐海鸟，并提供了最多的食物。几乎所有的内脏都被海鸟吃掉，主要是海鸟，因为它们的攻击性将其他物种排除在外。富尔玛通常忽视被丢弃的整条鱼，这些鱼主要被大黑背鸥Larus marinus、Gannet Sula basana和Great Skuas Sinaracta skua捕获。虽然比目鱼通常被忽视，因为海鸟发现它们很难吞咽，而且它们下沉得更快，但大多数被丢弃的圆鱼都被吃掉了。鲱鱼、小黑背鸥和小黑背鸥很少能获得内脏或废物。鲱鱼鸥和较小的黑背鸥花了很多时间在觅食的鸟群的外围，而猫尾鸥甚至很少尝试加入这些鸟群。拖网渔船上的大多数鸟类都是成年鸟，这表明幼鸟的比例很低，这进一步反映了拖网渔船上竞争激烈的摄食条件。我们认为，在不久的将来，捕鱼方式和海鸟种群数量的可能变化可能会导致鲱鱼、较小的黑嘴鸥和大Skuas发现以拖网渔船周围的废物为食变得越来越困难，因此它们可能会进一步被黄嘴鸥、大黑嘴鸥和大黑嘴鸥取代。
Among the different types of fishing vessels around Shetland, whitefish trawlers attract the largest numbers of scavenging seabirds and provide the most food. Offal was almost all consumed by seabirds, predominantly by Fulmars Fulmarus glacialis, which excluded other species by their aggression. Fulmars generally ignored discarded whole fish, which were mainly taken by Great Black-backed Gulls Larus marinus, Gannets Sula bassana and Great Skuas Catharacta skua. Although flatfish were usually ignored because seabirds found them difficult to swallow and they sank faster, most discarded roundfish were consumed. Herring Gulls L. argentatus, Lesser Black-backed Gulls L. fuscus and Kittiwakes Rissa tridactyla were rarely able to obtain offal or discards. Herring Gulls and Lesser Black-backed Gulls spent much time on the periphery of feeding flocks while Kittiwakes rarely attempted even to join these. Most of the birds at trawlers were in adult plumage, and it is suggested that the low proportion of immature birds present was a further reflection of the highly competitive feeding conditions at trawlers. We suggest that likely changes in fishing practice and seabird population sizes in the immediate future may result in Herring Gulls, Lesser Black-backed Gulls and Great Skuas finding feeding on waste around trawlers increasingly difficult, so they may be further displaced by Fulmars, Gannets and Great Black-backed Gulls.