Intrinsic and extrinsic influences on vital rates of cougars (puma concolor) in a hunted population

Abstract

Cougars are solitary, so their life-history performance should depend primarily on individual characteristics and interactions with their environment, making them well suited for studying the effects of individual traits, conspecific density, and extrinsic factors on vital rates. I developed generalized-linear models to identify influences on survival and reproduction in an Alberta population during 1981-1994, based on previously collected data. Recently-independent offspring, older individuals, and males survived least successfully. During winter, survival increased if cougars frequented habitats > 1.4 km ( ¥ ) or >2.2 km (o ) from a highway, between 1445-1678 m ( ¥ ) or 1513-1646 m (o ) elevation, and with <33 % (¥ ) or <41 % (o ) closed-canopy cover (>50% and >45% opencanopy cover) within 1 km2. Survival was higher during dry winters and following wet spnngs. Productive females were older and frequented habitats with <31 % closed-canopy cover (>48% open-canopy cover) within 1.0 km2. Mothers that occupied mid-elevation habitats raised larger litters, and those that experienced harsh conditions or reproduced during low cougar density produced female-biased litters.