The benefit of being a social butterfly: communal roosting deters predation
The benefit of being a social butterfly: communal roosting deters predation
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DOI：
10.1098/rspb.2012.0203
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发表时间：
2012-07-22
影响因子：
4.7
通讯作者：
Reed, Robert D.
中科院分区：
文献类型：
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作者：
Finkbeiner, Susan D.;Briscoe, Adriana D.;Reed, Robert D.
具有镇静作用的西番莲属蝴蝶会在夜间形成公共栖息地。假设这种行为对于信息共享和/或反捕食者防御是有益的。为了更好地了解公共栖息的适应性价值，我们在实地研究中测试了这两个假设。通过检查蝴蝶离开自然栖息地的后续行为来解决信息共享假设。我们没有发现任何证据表明栖息地的同伴会互相追寻资源，因此没有为这一假设提供支持。反捕食者防御假设是通过在野外单独放置和聚集放置的鸟类不可区分的 Heliconiuserato 模型进行测试的。与模型聚合相比，在单独模型上观察到的捕食尝试次数明显更高。聚集规模和攻击率之间的这种关系表明，公共栖息的蝴蝶既享受到总体攻击频率降低的好处，又享受到猎物稀释效应的好处。公共栖息地可能通过集体警戒来威慑捕食者，其中引人注目的、难吃的猎物的聚集向捕食者传达了更有效的排斥信号。根据我们的研究结果，我们认为鸟类的捕食是维持赫利科尼乌斯公共栖息行为的关键选择压力。
Aposematic passion-vine butterflies from the genus Heliconius form communal roosts on a nightly basis. This behaviour has been hypothesized to be beneficial in terms of information sharing and/or anti-predator defence. To better understand the adaptive value of communal roosting, we tested these two hypotheses in field studies. The information-sharing hypothesis was addressed by examining following behaviour of butterflies departing from natural roosts. We found no evidence of roost mates following one another to resources, thus providing no support for this hypothesis. The anti-predator defence hypothesis was tested using avian-indiscriminable Heliconius erato models placed singly and in aggregations at field sites. A significantly higher number of predation attempts were observed on solitary models versus aggregations of models. This relationship between aggregation size and attack rate suggests that communally roosting butterflies enjoy the benefits of both overall decreased attack frequency as well as a prey dilution effect. Communal roosts probably deter predators through collective aposematism in which aggregations of conspicuous, unpalatable prey communicate a more effective repel signal to predators. On the basis of our results, we propose that predation by birds is a key selective pressure maintaining Heliconius communal roosting behaviour.