Educated predators make strategic decisions to eat defended prey according to their toxin content
Educated predators make strategic decisions to eat defended prey according to their toxin content
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DOI：
10.1093/beheco/arr206
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发表时间：
2012-03-01
影响因子：
2.4
通讯作者：
Rowe, Candy
中科院分区：
文献类型：
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作者：
Barnett, Craig A.;Skelhorn, John;Rowe, Candy
动物经常吃含有毒素的食物，以从它们所含的营养中获益。了解动物如何平衡摄入毒素的代价和获得营养的好处，对于理解反捕食者防御的进化，特别是警戒和模仿是很重要的。在这项研究中，我们测试了捕食者是否可以学会使用颜色信号来做出战略决策，决定何时将毒素含量不同的猎物纳入饮食中。我们给欧洲椋鸟（Sturnus vulgaris）每日会议的顺序提出黄粉虫（黄粉虫）。有3种类型的黄粉虫，可区分使用颜色信号：不设防黄粉虫注射水，轻度防御黄粉虫注射1%奎宁溶液，和中度防御黄粉虫注射3%奎宁溶液。鸟类学会了吃更多的无防御比防御的猎物和更温和比中度防御的猎物。至关重要的是，当我们使用食物限制来控制鸟类的能量状态时，我们发现它们增加了它们所吃的防御性猎物的数量，但保持了它们的相对偏好。鸟类根据它们对猎物所含毒素量的了解和它们当前的能量需求做出依赖于状态的决定。我们的研究结果提供了新的见解警戒信号的演变，也表明，我们可能需要开发新的模型的基础上的状态依赖行为的捕食者的拟态进化。我们的数据也有更广泛的影响，在一系列不同的生态场景的营养素-毒素权衡的研究。
Animals often eat foods containing toxins to benefit from the nutrients that they contain. Understanding how animals balance the costs of eating toxins with the benefits of gaining nutrients is important for understanding the evolution of antipredator defenses, particularly aposematism and mimicry. In this study, we tested whether predators could learn to use color signals to make strategic decisions about when to include prey that varied in their toxin content in their diets. We gave European starlings (Sturnus vulgaris) daily sessions of sequentially presented mealworms (Tenebrio molitor). There were 3 types of mealworm which were made discriminable using color signals: undefended mealworms injected with water, mildly defended mealworms injected with 1% quinine solution, and moderately defended mealworms injected with 3% quinine solution. Birds learned to eat more undefended than defended prey and more mildly than moderately defended prey. Crucially, when we manipulated the birds' energetic states using food restriction, we found that they increased the number of defended prey that they ate but maintained their relative preferences. Birds made state-dependent decisions based upon their knowledge of the amount of toxin prey contained and their current energetic need. Our results provide novel insights into the evolution of aposematic signals and also demonstrate that we may need to develop new models of the evolution of mimicry based on the state-dependent behavior of predators. Our data also have broader implications for the study of nutrient-toxin trade-offs across a range of different ecological scenarios.