Eurasian otter (Lutra lutra) prey selection in response to a variation of fish abundance
Eurasian otter (Lutra lutra) prey selection in response to a variation of fish abundance
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DOI：
10.1080/11250000903229809
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发表时间：
2010-03
影响因子：
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通讯作者：
L. Remonti;C. Prigioni;A. Balestrieri;S. Sgrosso;G. Priore
中科院分区：
文献类型：
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作者：
L. Remonti;C. Prigioni;A. Balestrieri;S. Sgrosso;G. Priore
摘要 2001 年和 2002 年，我们研究了意大利南部的欧亚水獭 (Lutra lutra) 鱼类选择，通过比较水獭饮食（805 个分析的扭伤）与通过电捕鱼估计的鱼类可用性。调查的河流以鲤鱼为主，尤其是鲢鱼（Leuciscus cephalus）、鳅（Rutilus rubilio）和鳅鱼（Alburnus sp.）。蟑螂和鲢鱼是扭伤记录中最常见的猎物。水獭主要吃小型猎物（总长度<90毫米）。鲢鳢的消费量与丰富程度有关，而蟑螂和鳀鱼的消费量则与其供应量不成比例。水獭在 2001 年和 2002 年都选择了蟑螂，并通过增加捕食频率而不是转向其他猎物来应对蟑螂可用性的下降 (–27.3%)。尽管水獭数量众多，但它们似乎明显避免阴凉。我们假设微生境选择的差异可能会影响鲤科动物对水獭捕食的敏感性。简要讨论了对鱼类群落可能产生的影响。
Abstract In 2001 and 2002 we studied Eurasian otter (Lutra lutra) fish selection in southern Italy by comparing otter diet (805 analysed spraints) with fish availability, estimated by electrofishing. The surveyed river was dominated by cyprinids, particularly by chub (Leuciscus cephalus), roach (Rutilus rubilio) and bleak (Alburnus sp.). Roach and chub were the most common prey recorded in spraints. Otters ate mainly small prey (total length < 90 mm). Chub were widely consumed according to abundance, whilst roach and bleak consumption was not proportionate to their availability. Otters selected roach both in 2001 and 2002 and responded to a decrease in roach availability (–27.3%) by increasing their frequency of consumption rather than switching to an alternative prey. Despite their high abundance, bleak seemed to be markedly avoided by otters. We hypothesized that differences in microhabitat selection may influence the susceptibility of cyprinids to otter predation. The possible effects on fish community were briefly discussed.