Adult survival pattern of the sexually dimorphic Alpine ibex (Capra ibex ibex)

Using recent developments in capture-recapture modeling, we analyzed the adult survival pattern of an Alpine ibex (Capra ibex ibex) population recently established in the northern Alps of France. Survival rates varied little over time and did not differ between the sexes. The survival rate was 0.97 (SE = 0.011). Recapture probabilities were stable over time but differed according to sex: 0.71 (SE = 0.035) for males versus 0.88 (SE = 0.033) for females. The absence of a between-sex difference in survival was not expected for a highly sexually dimorphic species. Environmental conditions, such as a low population density and a low pressure of limiting factors on population dynamics, could explain this absence of a survival cost of sexual selection for males. The high and rather constant survival rate of ibex over time is consistent with the idea that, in large mammals, individuals should be selected for maximizing their own adult survivorship.