Population Dynamics of San Joaquin Kit Foxes at the Naval Petroleum Reserves in California

We investigated the population dynamics of the endangered San Joaquin kit fox (Vulpes macrotis mutica) and factors that influence kit fox demographics at the Naval Petroleum Reserves in California (NPRC) during 1980-95. Kit fox abundance varied widely during this period and population estimates on a$216\text{-}{\rm km}^{2}$study area ranged from 46 ($0.21/{\rm km}^{2}$) in 1991 to 363 ($1.68/{\rm km}^{2}$) in 1994. The finite rate of increase (λ) ranged from 0.37 in 1995 to 2.22 in 1993. Of 341 adult and 184 juvenile foxes radiocollared, we recovered 225 and 142 dead, respectively. Mean annual survival rate for adults was 0.44 (range = 0.20-0.81) and the mean rate for juveniles from 1 May to 15 February (age 1) was 0.14 (range =