Turner Cameron Rouse, Spike Matt, Magrath Robert D
Computational Cognitive Science Lab, Department of Computer Science Princeton University Princeton New Jersey USA.
Division of Ecology and Evolution, Research School of Biology Australian National University Canberra Australian Capital Territory Australia.
Ecol Evol. 2023 Jul 12;13(7):e10272. doi: 10.1002/ece3.10272. eCollection 2023 Jul.
Interceptive eavesdropping on the alarm calls of heterospecifics provides crucial information about predators. Previous research suggests predator discrimination, call relevance, reliability, and reception explain when eavesdropping will evolve. However, there has been no quantitative analysis to scrutinize these principles, or how they interact. We develop a mathematical framework that formalizes the study of the key principles thought to select for eavesdropping. Interceptive eavesdropping appears to be greatly affected by the threat faced by caller and eavesdropper, as well as presence of informational noise affecting the detection of calls and predators. Accordingly, our model uses signal detection theory to examine when selection will favor alarm calling by a sender species and fleeing by an eavesdropping receiver species. We find eavesdropping is most strongly selected when (1) the receiver faces substantial threats, (2) species are ecologically similar, (3) senders often correctly discriminate threats, (4) receivers often correctly perceive calls, and (5) the receiver's personal discrimination of threats is poor. Furthermore, we find (6) that very high predation levels can select against eavesdropping because prey cannot continuously flee and must conserve energy. Reliability of heterospecific calls for identifying threats is thought to be important in selecting for eavesdropping. Consequently, we formally define reliability, showing its connection to specificity and sensitivity, clarifying how these quantities can be measured. We find that high call relevance, due to similar vulnerability to predators between species, strongly favors eavesdropping. This is because senders trade-off false alarms and missed predator detections in a way that is also favorable for the eavesdropper, by producing less of the costlier error. Unexpectedly, highly relevant calls increase the total number of combined errors and so have lower reliability. Expectedly, when noise greatly affects personally gathered cues to threats, but not heterospecific calls or detection of predators, eavesdropping is favored.
对异种动物警报叫声的拦截窃听能提供有关捕食者的关键信息。先前的研究表明，捕食者辨别能力、叫声相关性、可靠性和接收能力可以解释窃听行为何时会进化。然而，尚未有定量分析来审视这些原则，也没有分析它们是如何相互作用的。我们开发了一个数学框架，将用于选择窃听行为的关键原则的研究形式化。拦截窃听行为似乎受到发出警报者和窃听者所面临威胁的极大影响，以及影响叫声和捕食者检测的信息噪声的存在。因此，我们的模型使用信号检测理论来研究何时选择会有利于发出警报的物种发出警报以及有利于进行窃听的接收物种逃离。我们发现，在以下情况下，窃听行为最有可能被选择：（1）接收者面临重大威胁；（2）物种在生态上相似；（3）发出警报者经常能正确辨别威胁；（4）接收者经常能正确感知叫声；（5）接收者对威胁的个人辨别能力较差。此外，我们发现（6）极高的捕食水平可能会选择不进行窃听，因为猎物无法持续逃离且必须保存能量。异种动物叫声在识别威胁方面的可靠性被认为在选择窃听行为中很重要。因此，我们正式定义了可靠性，展示了它与特异性和敏感性的联系，阐明了如何测量这些量。我们发现，由于物种之间对捕食者的易受性相似，高叫声相关性强烈有利于窃听。这是因为发出警报者在误报和错过捕食者检测之间进行权衡，这种方式对窃听者也有利，因为产生的代价更高的错误更少。出乎意料的是，高度相关的叫声会增加总错误数，因此可靠性较低。不出所料，当噪声极大地影响个人收集的威胁线索，但不影响异种动物叫声或捕食者检测时，窃听行为会受到青睐。
