Sickness behaviour acting as an evolutionary trap? Male house finches preferentially feed near diseased conspecifics
Sickness behaviour acting as an evolutionary trap? Male house finches preferentially feed near diseased conspecifics
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DOI：
10.1098/rsbl.2010.0020
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发表时间：
2010-08-23
期刊：
影响因子：
3.3
通讯作者：
Hawley, Dana M.
中科院分区：
文献类型：
--
作者：
Bouwman, Karen M.;Hawley, Dana M.
宿主对感染性同种物质的行为是病原体动态中一个重要但被忽视的组成部分。预计选择将有利于那些能够识别和避免感染同种病毒的人，以降低他们自己感染的风险。然而，证据很少，而且仅限于使用化学线索的物种。在这里，我们实验地检查了健康的圈养家雀(Carpodacus Micianus)是否优先在同性、健康的同种附近觅食，而不是感染了直接可传播的病原体鸡毒支原体(MG)，这种病原体会导致嗜睡和明显的结膜炎。有趣的是，雄性家雀强烈喜欢在患病的同种鸟类附近觅食，而雌性家雀则没有表现出偏好。这种性别差异似乎是因为患病男性的攻击率较低，而不是女性。患病雄性的攻击性减少可能会在一个新的环境中呈现出历史上有益的行为线索，这可能是一种“进化陷阱”，现在新的环境中包括了一种最近出现的潜在致命的病原体。由于MG可以在喂养过程中直接传播，健康的男性可能会无意中增加感染MG的风险。这一行为可能极大地促进MG在野生种群中的持续流行。
Host behaviour towards infectious conspecifics is a crucial yet overlooked component of pathogen dynamics. Selection is expected to favour individuals who can recognize and avoid infected conspecifics in order to reduce their own risk of infection. However, evidence is scarce and limited to species employing chemical cues. Here, we experimentally examine whether healthy captive house finches (Carpodacus mexicanus) preferentially forage near a same-sex, healthy conspecific versus one infected with the directly transmissible pathogen Mycoplasma gallisepticum (MG), which causes lethargy and visible conjunctivitis. Interestingly, male house finches strongly preferred feeding near diseased conspecifics, while females showed no preference. This sex difference appeared to be the result of lower aggression rates in diseased males, but not in females. The reduced aggression of diseased males may act as an 'evolutionary trap' by presenting a historically beneficial behavioural cue in the context of a new environment, which now includes a recently emerged, potentially fatal pathogen. Since MG can be directly transmitted during feeding, healthy males may inadvertently increase their risk of contracting MG. This behaviour is likely to significantly contribute to the continued persistence of MG epidemics in wild populations.