Patterns and coevolutionary consequences of repeated brood parasitism.
نویسندگان
چکیده
The absence of adaptive host responses to virulent parasites and pathogens is paradoxical. We explored the theoretical possibility that the evolution of antiparasitic egg-ejection strategies was delayed by avian hosts' lifetime experiences with brood parasitism. An analytical model indicated that individual hosts' repeated exposure to parasitism decreased the relative benefits of learning-based rejecter strategies when parasitism was particularly costly. Because brood parasitic brown-headed cowbirds (Molothrus ater) and their hosts are typically philopatric across breeding attempts, spatially and temporally non-random patterns of parasitism may contribute to low levels of observed egg-ejection by vulnerable cowbird hosts. In support, we found that in three populations of two host species individual females experienced repeated cowbird parasitism during their lifetimes. We propose that repeated parasitism contributes to counterintuitive patterns of coevolutionary dynamics in spatially structured host-parasite populations.
منابع مشابه
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Coevolutionary arms races, where adaptations in one party select for counter-adaptations in another and vice versa, are fundamental to interactions between organisms and their predators, pathogens, and parasites [1]. Avian brood parasites and their hosts have emerged as model systems for studying such reciprocal coevolutionary processes [2, 3]. For example, hosts have evolved changes in egg app...
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عنوان ژورنال:
- Proceedings. Biological sciences
دوره 271 Suppl 5 شماره
صفحات -
تاریخ انتشار 2004