SURVIVORSHIP AND CAUSE-SPECIFIC MORTALITY IN 5 POPULATIONS OF MULE DEER

We used retrospective analyses to investigate cause-specific mortality and survivorship among 5 populations of mule deer (N = 168 telemetere d animals) wintering in the western Great Basin during 1986-1994. Thes e populations existed under similar environmental conditions, but surv ivorship functions differed among them. Monthly survival ranged from 0 .964 to 0.990, and annual survival ranged from 0.643 to 0.884. The pro portion of deaths attributed to predation and malnutrition or anthropo genic causes did not differ among the 5 populations. Predation was the leading cause of mortality; mountain lions were responsible for appro ximately 90% of the deer killed by predators. No difference existed am ong these populations in the proportion of telemetered deer that were killed by mountain lions, but proportionally more females than males w ere killed by these large felids. Predation by mountain lions is the p rimary source of mortality and a widespread phenomenon among the popul ations of mule deer we investigated.