摘要

Avoidance of predation can impose opportunity costs on prey species that use behavioural avoidance strategies to evade detection. An animal that spends much time hiding or remaining immobile, for example, may have less time for other important activities such as foraging or finding mates. Here we examine the idea that the evolution of chemical defence may act to release prey from these constraints, freeing defended prey to exploit their habitats more effectively, and increasing their niche space. We tested this hypothesis using comparative methods on a mammal group containing both chemically defended and non-defended species: Musteloidea. We found that defended species had a more omnivorous diet and were more likely to be active during both day and night than non-defended species. We also found that chemically defended species were less likely to be strictly diurnal or to show sexual size dimorphism, and had earlier maturing females and a shorter lifespan than non-defended species. Taken together, our results support the hypothesis that chemical defence increases the niche space available to a species. More generally, this also supports recent suggestions that strategies taken to avoid natural enemies can have important effects on diverse components of life history.

  • 出版日期2013-9