Data from: The comparative effects of large carnivores on the acquisition of carrion by scavengers

Pumas (Puma concolor) and black bears (Ursus americanus) are large carnivores that may influence scavenger population dynamics. We used motion-triggered video cameras deployed at deer carcasses to determine how pumas and black bears affected three aspects of carrion acquisition by scavengers: presence, total feeding times, and mean feeding bout durations. We found that pumas were unable to limit acquisition of carrion by large carnivores, but limited aspects of carrion acquisition of both birds and mesocarnivores. Through their suppression of mesocarnivores and birds, pumas apparently initiated a cascading pattern and increased carrion acquisition of small carnivores. In contrast, black bears monopolized carrion resources and generally had larger limiting effects on carrion acquisition of all scavengers. Black bears also limited puma feeding behaviors at puma kills, which may require pumas to compensate for energetic losses through increasing their kill rates of ungulates. Our results suggest that pumas provide carrion and selectively influence species acquiring carrion, while black bears limit carrion availability to all other scavengers. These results suggest that the effects of large carnivores on scavengers depend on attributes of both carnivores and scavengers (including size) and that competition for carcasses may result in intraguild predation as well as mesocarnivore release.美洲狮（Puma concolor）与美洲黑熊（Ursus americanus）均为大型食肉动物，二者可能会对食腐动物的种群动态产生影响。本研究通过部署在鹿类尸体旁的运动触发式摄像机，探究美洲狮与美洲黑熊如何影响食腐动物获取腐肉的三个维度：食腐动物的出现情况、总取食时长，以及单次取食回合的平均时长。研究结果显示，美洲狮无法限制大型食肉动物对腐肉的获取，但会抑制鸟类与中型食肉动物的腐肉获取行为。通过压制中型食肉动物与鸟类种群，美洲狮似乎引发了营养级联效应，并提升了小型食肉动物的腐肉获取量。与之形成对比的是，美洲黑熊会垄断腐肉资源，且普遍对所有食腐动物的腐肉获取行为产生更强的抑制效应。此外，美洲黑熊还会限制美洲狮在其捕杀的猎物处的取食行为，这可能迫使美洲狮通过提升有蹄类动物的捕杀率来弥补能量损失。本研究结果表明，美洲狮会提供腐肉资源并选择性地影响获取腐肉的物种，而美洲黑熊则会限制其他所有食腐动物可获得的腐肉资源量。上述结果显示，大型食肉动物对食腐动物的影响取决于食肉动物与食腐动物自身的属性（包括体型大小），而腐肉资源的竞争可能同时引发集团内捕食（intraguild predation）与中型食肉动物释放效应（mesocarnivore release）。