Preliminary analysis of reproductive success in a large mammal with alternative mating tactics, the Northern chamois, Rupicapra rupicapra

摘要

In polygynous mating systems, reproductive skew depends on the ability of males to monopolize females, which in turn may promote the development of contrasting traits in the two sexes. Although dominant individuals normally enjoy a higher reproductive success (RS) than subordinates, the use of genetic markers has shown that behavioural observations of male mating success may not provide reliable clues of RS. We report the preliminary results of the first DNA-based paternity analysis on the Northern chamois (Rupicapra rupicapra), a scarcely dimorphic mountain ungulate described as highly polygynous, in relation to mating tactic and age. Because of sampling difficulties, the success in parentage assignment was low, and the interpretation of results requires caution. Territorial males had a greater RS than nonterritorial ones but they were unable to monopolize mating events. Age had a weak effect on paternity outcome but only males 6years showed siring success. Although future studies are needed to assess the opportunity for sexual selection in male chamois, the concurrence of limited sexual size dimorphism, compensatory growth, unbiased sex-specific survival, RS of alternative mating tactics and, possibly, long breeding tenure, may hint at the adoption of a conservative mating strategy in this species.