Invasive mammalian predators can cause the decline and extinction of vulnerable native species. Many invasive mammalian predators are dietary generalists that hunt a variety of prey. These predators often rely upon olfaction when foraging, particularly at night. Little is understood about how prey odor cues are used to inform foraging decisions. Prey cues can vary spatially and temporally in their association with prey and can either reveal the location of prey or lead to unsuccessful foraging. Here we examine how two wild‐caught invasive mammalian bird predator species (European hedgehogs Erinaceus europaeus and ferrets Mustela putorius furo) respond to unrewarded bird odors over successive exposures, first demonstrating that the odors are perceptually different using house mice (Mus musculus) as a biological olfactometer. We aim to test if introduced predators categorize odor cues of similar prey together, a tactic that could increase foraging efficiency. We exposed house mice to the odors using a standard habituation/dishabituation test in a laboratory setting, and wild‐caught European hedgehogs and ferrets in an outdoor enclosure using a similar procedure. Mice discriminated among all bird odors presented, showing more interest in chicken odor than quail or gull odor. Both predator species showed a decline in interest toward unrewarded prey odor (i.e., habituation), but only ferrets generalized their response from one unrewarded bird odor to another bird odor. Hedgehog responses to unrewarded bird odors were highly variable between individuals. Taken together, our results reveal interspecific and intraspecific differences in response to prey odors, which we argue are a consequence of different diet breadth, life and evolutionary histories, and the conditions in each experiment. Generalization of prey odors may have enabled some species of invasive predators to efficiently hunt a range of intraguild prey species, for example, ground‐nesting shorebirds. Olfactory manipulation of predators may be a useful conservation tool for threatened prey if it reduces the conspicuousness of vulnerable prey.

中文翻译：

---

侵入性哺乳动物的捕食者习惯于并概括鸟类的猎物线索：一种保护本地猎物的机制。

侵入性的哺乳动物天敌会导致脆弱的本地物种的灭绝和灭绝。许多侵入性的哺乳动物捕食者都是饮食多面手，他们会猎食各种猎物。这些捕食者在觅食时尤其是在夜间经常依赖嗅觉。对于如何使用猎物气味提示来进行觅食决策知之甚少。猎物线索与猎物的关联在空间和时间上可能会发生变化，并且可能揭示猎物的位置或导致觅食失败。在这里，我们研究了两种野生入侵的哺乳动物鸟类捕食者物种（欧洲刺猬Erinaceus europaeus和雪貂鼬鼬）在连续暴露后对未奖励鸟类气味的反应，首先证明了使用家鼠的气味在感觉上是不同的（小家鼠）作为生物嗅觉计。我们的目的是测试引入的捕食者是否将相似猎物的气味线索归类在一起，从而提高觅食效率。我们在实验室环境中使用标准的适应/适应测试，将家鼠暴露在气味下，并在野外用类似的程序在室外封闭的野外捕获的欧洲刺猬和雪貂。小鼠区分了所呈现的所有鸟的气味，对鸡的气味比鹌鹑或海鸥的气味更感兴趣。两种捕食者对未奖励的猎物气味（即习惯化）的兴趣都下降了，但只有雪貂才将其反应从一种不奖励的鸟气味推广到另一种鸟的气味。刺猬对难闻的鸟类气味的反应在个体之间差异很大。在一起 我们的结果揭示了对猎物气味的种间和种内差异，我们认为这是不同饮食广度，生活和进化史以及每个实验条件的结果。猎物气味的泛化可能使某些侵入性捕食者物种能够有效地猎捕行会内部的各种猎物物种，例如，地面筑巢的shore鸟。如果捕食者的嗅觉处理能够减少易受攻击的猎物的显眼性，则它可能是一种有用的养护受威胁猎物的工具。地面筑巢的水鸟。如果捕食者的嗅觉处理能够减少易受攻击的猎物的显眼性，则它可能是一种有用的养护受威胁猎物的工具。地面筑巢的水鸟。如果捕食者的嗅觉处理能够减少易受攻击的猎物的显眼性，则它可能是一种有用的养护受威胁猎物的工具。