Apparent demographic changes in black-tailed deer associated with wolf control on northern Vancouver Island

Publisher Website
Google Scholar
Abstract
A simple difference equation model was used to provide a perspective on demographic changes in a Columbian black-tailed deer (Odocoileus hemionus columbianus) population prior to and during wolf (Canis lupus) control on northern Vancouver Island. The model reconstructed spring (pre-fawning) deer numbers and adult survival rates from an annual abundance index, the proportion of the population consisting of juveniles 10–11 months of age, and hunter harvest. The actual (λ) and potential (λp, in the absence of hunting) rates of deer population change, adult nonhunting survival (Sn), adult hunting mortality (Mh) and recruitment (R) rates were estimated for three growth periods: (1) predecline (1970–1976), wolf numbers low but increasing, λ = 1.02, λp = 1.13, Sn = 0.90, Mh = 0.09, R = 0.22; (2) decline (1976–1983), wolves abundant, λ = 0.81, λp = 0.85, Sn = 0.76, Mh = 0.05, R = 0.09; and (3) recovery (1983–1990), wolves reduced, λ = 1.17, λp = 1.24, Sn = 0.94, Mh = 0.03, R = 0.23. The recruitment (Rs) required to balance adult mortality (λ = 1.00) was ~16%. Sensitivity analyses using plausible extremes in demographic rates suggested that changes in juvenile survival had the greatest impact on recruitment. Rate of population change appeared to be most sensitive to juvenile survival and adult nonhunting survival.

This publication has 0 references indexed in Scilit: