Estimating effects of adult male mortality on grizzly bear population growth and persistence using matrix models

摘要: We radio monitored a hunted, sexually segregated grizzly bear (Ursus arctos) population and an unhunted, unsegregated for demographics constructed stage- age-classified matrix model to test the effects of adult male mortality resulting sexual segregation on growth persistence. Population parameters in were female survival, subadult offspring probability litter sizes, unsuccessful pregnancy. The last three affected by segregation, others not. compared with without hunting holding survival constant using hunted unhunted values size, (Lambda) showed greatest elasticity pregnancy, that order. This corresponds observed anti-infanticide tactics (sexual segregation) females maximize their fitness. decreased at rate 0.99 whereas simulated, increased 1.05. was much more susceptible extinction. Under demographic stochasticity mean time extinction 32 years 110 population. environmental stochasicity 21 43 suggest caused resident males can result decline even contribute rapid extinctions when numbers are small.