EFFECTS OF AGE, SEX, DISEASE, AND DENSITY ON SURVIVAL OF BIGHORN SHEEP

摘要: Longitudinal studies of survival are valuable because age-specific affects population dynamics and the evolution several life history traits. We used capture–mark–recapture models to assess relationship between sex, age, population, year study, disease, winter weather, density in two populations bighorn sheep (Ovis canadensis) Alberta, Canada. The Ram Mountain monitored for 20 yr, more than doubled density; Sheep River 13 experienced a pneumonia epizootic. Yearling varied among years was lower that older same except yearling males at Mountain. females were only sex-age class exhibiting dependence survival. Senescence evident both sexes populations. Female from age 2 7 very high populations, but aged 3 yr enjoyed better 4–6 yr. Our data support suggestion where hunters remove many 5 natural mortality increases 3–5 possibly young suffer cost participating rutting activity. decline greater females. Survival females, prime-aged (0.896 vs. 0.939 River; 0.837 0.945 Mountain) (0.777 0.859 0.624 0.850 Mountain), not yearlings. 2–7 significantly different Winter weather did affect vary years, Studies mountain based upon skull collections may have overestimated rams. results underline need accurate information on