Division of Biological Sciences, University of Missouri, Columbia, MO 65211, USA.
Proc Biol Sci. 2012 Sep 22;279(1743):3820-6. doi: 10.1098/rspb.2012.1181. Epub 2012 Jul 11.
Within animal groups, individuals can learn of a predator's approach by attending to the behaviour of others. This use of social information increases an individual's perceptual range, but can also lead to the propagation of false alarms. Error copying is especially likely in species that signal collectively, because the coordination required for collective displays relies heavily on social information. Recent evidence suggests that collective behaviour in animals is, in part, regulated by negative feedback. Negative feedback may reduce false alarms by collectively signalling animals, but this possibility has not yet been tested. We tested the hypothesis that negative feedback increases the accuracy of collective signalling by reducing the production of false alarms. In the treehopper Umbonia crassicornis, clustered offspring produce collective signals during predator attacks, advertising the predator's location to the defending mother. Mothers signal after evicting the predator, and we show that this maternal communication reduces false alarms by offspring. We suggest that maternal signals elevate offspring signalling thresholds. This is, to our knowledge, the first study to show that negative feedback can reduce false alarms by collectively behaving groups.
在动物群体中，个体可以通过观察其他个体的行为来了解捕食者的逼近。这种利用社会信息的方法增加了个体的感知范围，但也可能导致误报的传播。在集体发出信号的物种中，错误复制尤其可能发生，因为集体展示所需的协调严重依赖于社会信息。最近的证据表明，动物的集体行为部分受到负反馈的调节。负反馈可以通过集体信号来减少动物的误报，但这种可能性尚未得到验证。我们测试了一个假设，即负反馈通过减少虚假警报的产生来提高集体信号的准确性。在叶蝉 Umbonia crassicornis 中，成群的后代在受到捕食者攻击时会发出集体信号，向保护它们的母亲报告捕食者的位置。母亲在驱赶捕食者后会发出信号，我们发现这种母性通讯可以减少后代的误报。我们认为，母性信号提高了后代的信号阈值。据我们所知，这是第一项表明负反馈可以减少集体行为群体误报的研究。
