Density-dependent individual variation in male attractiveness in a wild field cricket
Density-dependent individual variation in male attractiveness in a wild field cricket
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DOI：
10.1093/beheco/arab009
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发表时间：
2021-04-21
影响因子：
2.4
通讯作者：
Dingemanse, Niels J.
中科院分区：
文献类型：
--
作者：
Niemela, Petri T.;Tiso, Stefano;Dingemanse, Niels J.
社会环境改变了雄性吸引雌性的能力，从而影响了它的适合度。理论认为，个体的适应能力应该与其应对竞争的能力相权衡。个体应该以不同的方式解决这种权衡：一些雄性在低密度时更有吸引力，而另一些则在高密度时更有吸引力。这种预测很少在野外得到验证。我们使用自动射频识别监控系统，在30天内（即几乎是我们模型生物的整个成年寿命），每天每小时量化一只雄性是否在其洞穴中吸引了一只雌性。这些数据是在野外蟋蟀（Gryllus campestris）的自然密度变化范围内收集的。我们还估计了吸引力和密度之间关系的形状是否经过了选择。在种群水平上，从低密度到中等密度的吸引力增加，表明存在Allee效应。例如，在人口密度较高时，由于竞争加剧的不利影响，吸引力随后下降。与预期相反，在低密度下更有吸引力的雄性在高密度下也更有吸引力。然而，随着密度的增加，男性的吸引力有所不同，这表明Allee效应是个体特异性的。最后，选择并不是依赖于密度的吸引力，而是长寿的雄性获得了更多的交配对象。我们的研究揭示了社会环境塑造了野生雄性昆虫的吸引力，并暗示了个体特异性Allee效应的发生，这种效应可能是可进化的。
Social environments modify a male's ability to attract females and thus affect its fitness. Theory implies that an individual's fitness should trade-off with its ability to cope with competition. Individuals are expected to solve this trade-off differently: some males should be more attractive at low but others instead at high density. This prediction has rarely been tested in the wild. We used an automated RFID-surveillance system to quantify for each hour of the day, over 30 days (i.e., almost the entire adult lifespan of our model organism), whether a male had attracted a female in its burrow. The data were collected across a range of naturally varying local densities in wild field crickets, Gryllus campestris. We also estimated whether the shape of the relationship between attractiveness and density was under selection. At the population level, attractiveness increased from low to intermediate density, suggesting an Allee effect. Attractiveness subsequently declined at higher densities, for example, because of detrimental effects of increased competition. Opposite to expectations, males that were more attractive under low densities were also more attractive under higher densities. However, the increase in attractiveness with density varied among males, suggesting that Allee effects were individual-specific. Finally, selection was not acting on density-dependent attractiveness but males that lived longer acquired more mating partners. Our study reveals that social environments shape attractiveness in wild male insects, and imply the occurrence of individual-specific Allee effect that may be evolvable.