Recolonizing carnivores: Is cougar predation behaviorally mediated by bears? Cougar Killsite Data

Conservation and management efforts have resulted in population increases and range expansions for some apex predators, potentially changing trophic cascades and predatory behavior. Changes in sympatric carnivore and dominant scavenger populations provide opportunities to assess how carnivores affect one another. Cougars (Puma concolor) were the apex predator in the Great Basin of Nevada, USA, for over 80 years. Black bears (Ursus americanus) have recently recolonized the Great Basin and are known to heavily scavenge on cougar kills; however, competitive interactions between the two species in the Great Basin have yet to be examined. We investigated kill sites of 31 cougars between 2009 and 2017 across a range of bear densities to evaluate the impacts of sympatric, recolonizing bears on cougar foraging behavior. We modeled the variation in feeding bout duration (number of nights spent feeding on a prey item) and the proportion of primary prey, mule deer (Odocoileus hemionus), in cougar ...保护与管理举措已促使部分顶级捕食者种群数量增长、分布范围扩张，这可能会改变营养级联效应与捕食行为。同域分布食肉动物与优势食腐动物种群的动态变化，为探究食肉物种间的相互影响机制提供了研究契机。美洲狮（Puma concolor）曾作为美国内华达州大盆地（Great Basin）的顶级捕食者长达80余年。近期，美洲黑熊（Ursus americanus）重新定居至大盆地，且已知其会大量取食美洲狮的猎物残骸；但目前学界尚未针对该区域内两种物种间的竞争互动展开相关研究。本研究于2009至2017年间，针对不同黑熊种群密度区域内的31只美洲狮的猎物取食位点开展调查，以评估同域分布、重新定居的黑熊对美洲狮觅食行为的影响。我们对取食时长（即单猎物个体上的取食夜晚数）的变化，以及美洲狮食谱中主要猎物骡鹿（Odocoileus hemionus）的占比进行建模分析，……