Candolin U, Voigt Hr
Department of Biology, University of Turku
Anim Behav. 1998 Nov;56(5):1205-1211. doi: 10.1006/anbe.1998.0892.
Reproductive activities often increase the susceptibility of individuals to predators. Individuals may be able to reduce this risk of predation, however, by their choice of breeding habitat, as the structural complexity of habitats is known to affect predator foraging success. Here we show that the presence of predators induces a preference for structurally complex nest sites over open ones in male three-spined sticklebacks, Gasterosteus aculeatus. To investigate whether this predator-induced nest site preference can decrease the known negative effect of predators on courtship activity, we recorded the reduction in courtship activity during predator presentations for males in vegetated and open nest sites. Habitat structure affected the response to a predator when males were in competition. A male in a vegetated site reduced courtship activity less than a male in an open site. Habitat had no effect on courtship when males were solitary, however. This suggests that male-male competition and the possibility of losing mating opportunities to other males affect risk taking. Females, who were unaware of the predator, preferred the male in the vegetated site, which showed less reduction in courtship, when the males were exposed to a predator, but chose randomly between the males when the predator was absent. Thus, a preference for vegetated nest sites under predation risk may be beneficial not only by increasing the probability of survival, but also by reducing the negative impact of predators on courtship activity and mating probability. Copyright 1998 The Association for the Study of Animal Behaviour.
繁殖活动往往会增加个体被捕食的易感性。然而，个体或许能够通过选择繁殖栖息地来降低这种被捕食的风险，因为已知栖息地的结构复杂性会影响捕食者的觅食成功率。在此我们表明，在雄性三刺鱼（Gasterosteus aculeatus）中，捕食者的存在会使其偏好结构复杂的巢穴地点而非开阔的巢穴地点。为了研究这种由捕食者引发的巢穴地点偏好是否能够减少捕食者对求偶活动已知的负面影响，我们记录了在向处于植被丰富和开阔巢穴地点的雄性三刺鱼展示捕食者时求偶活动的减少情况。当雄性三刺鱼处于竞争状态时，栖息地结构会影响其对捕食者的反应。处于植被丰富地点的雄性三刺鱼求偶活动减少的程度小于处于开阔地点的雄性三刺鱼。然而，当雄性三刺鱼单独存在时，栖息地对求偶活动没有影响。这表明雄性之间的竞争以及失去与其他雄性交配机会的可能性会影响冒险行为。当雄性三刺鱼暴露于捕食者时，未察觉到捕食者的雌性更偏好处于植被丰富地点、求偶活动减少程度较小的雄性三刺鱼，但在没有捕食者时则在雄性三刺鱼之间随机选择。因此，在存在捕食风险的情况下对植被丰富的巢穴地点的偏好可能不仅通过增加生存概率而有益，还通过减少捕食者对求偶活动和交配概率的负面影响而有益。版权所有1998动物行为研究协会。
