The effect of feral cats on the population viability of black‐vented shearwaters (Puffinus opisthomelas) on Natividad Island, Mexico
The effect of feral cats on the population viability of black‐vented shearwaters (Puffinus opisthomelas) on Natividad Island, Mexico
复制标题
野猫对墨西哥纳蒂维达岛黑嘴海鸥 (Puffinus opisthomelas) 种群活力的影响
DOI：
10.1017/s1367943002002263
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发表时间：
2002
影响因子：
3.4
通讯作者：
C. Donlan
中科院分区：
文献类型：
--
作者：
B. Keitt;C. Wilcox;B. Tershy;D. Croll;C. Donlan
岛屿繁殖海鸟可能特别容易受到引入的哺乳动物捕食者的伤害，因为它们往往缺乏对捕食的行为，形态和生活史防御。我们研究了墨西哥南下加利福尼亚的Natividad岛上的黑腹剪水（Puffinus opisthomelas）的生活史，以研究其对引入野猫的脆弱性。使用异速生长方程，我们估计野猫每天消耗328 g食物以满足其营养需求。我们使用猫粪便的稳定同位素分析来估计90%的猫的饮食是由剪切水。利用我们的重点物种和密切相关的马恩岛剪水（Puffinus puffinus）的数据，我们创建了一个人口统计模型，以评估猫种群规模对剪水的年增长率（λ）的影响。在没有猫科动物捕食的情况下，黑腹剪水的年增长率估计为1.006。在捕食的情况下，我们估计在15万只鸟的种群中，每20只猫的年增长率下降约5%。鸟类种群的持续时间随着野猫种群规模的增加和初始鸟类种群规模的减少而减少。
Insular breeding seabirds are likely to be particularly vulnerable to introduced mammalian predators because they often lack behavioural, morphological and life‐history defenses against predation. We studied the life‐history of the black‐vented shearwater (Puffinus opisthomelas) on Natividad Island, Baja California Sur, Mexico, to examine its vulnerability to introduced feral cats. Using an allometric equation, we estimated that feral cats consumed 328 g of food day‐1 to satisfy their nutritional requirements. We used stable isotope analysis of cat scat to estimate that 90% of the cats' diet was composed of shearwaters. Using data from our focal species and from the closely related manx shearwater (Puffinus puffinus), we created a demographic model to evaluate the effects of cat population size on the annual growth rate (λ) of the shearwater. The annual growth rate for black‐vented shearwaters was estimated to be 1.006 in the absence of cat predation. With predation, we estimated that annual growth rate declined approximately 5% for every 20 cats in a population of 150,000 birds. Persistence times of bird colonies decreased both with an increase in the size of the feral cat population and with a decrease in the size of the initial bird population.