Centre for Ecology and Conservation, School of Biosciences, University of Exeter, Cornwall Campus, Penryn TR10 9EZ, UK.
Curr Biol. 2011 Oct 25;21(20):1716-9. doi: 10.1016/j.cub.2011.08.053. Epub 2011 Oct 6.
Males frequently remain in close proximity to their mate immediately postcopulation. This behavior has generally been interpreted as a guarding tactic designed to reduce the likelihood that a rival male can rapidly displace the ejaculate of the guarding male [1, 2]. Such attempts by males to control their mates represent a potential source of conflict [3-5], but guarding behaviors in species where it is difficult for males to control their mates suggest that conflict is not inevitable [6, 7]. We employed a network of infrared video cameras to study a wild population of individually marked and genotyped field crickets (Gryllus campestris). Lone females or males suffer similar rates of predation, but when a pair is attacked, the male allows the female priority access to their burrow, and in doing so dramatically increases his probability of being killed. In compensation for this increased predation risk, paired males mate more frequently and father more of the female's offspring. By staying with a male, females increase the sperm contribution of preferred males as well as reducing their predation risk. In contrast to conclusions based on previous lab studies, our field study suggests that mate guarding can evolve in a context of cooperation rather than conflict between the sexes.
雄性动物通常在交配后会与伴侣保持近距离。这种行为通常被解释为一种保护策略，旨在降低竞争对手迅速取代保护雄性的精液的可能性[1,2]。雄性试图控制其伴侣的行为代表了潜在的冲突源[3-5]，但在雄性难以控制其伴侣的物种中，保护行为表明冲突并非不可避免[6,7]。我们利用红外视频摄像机网络研究了一个经过个体标记和基因分型的野外蟋蟀（Gryllus campestris）种群。单独的雌性或雄性遭受相似的捕食率，但当一对蟋蟀受到攻击时，雄性会让雌性优先进入洞穴，从而极大地增加了自己被杀死的概率。作为对这种增加的捕食风险的补偿，配对的雄性会更频繁地交配并使更多的雌性后代受精。通过与雄性在一起，雌性会增加首选雄性的精子贡献，同时降低其捕食风险。与基于之前实验室研究的结论相反，我们的野外研究表明，在两性之间合作而非冲突的背景下，伴侣保护可能会进化。
