Condition of San Joaquin kit foxes in urban and exurban habitats

We compared condition of endangered San Joaquin kit foxes (Vulpes macrotis mutica) between an urban population in Bakersfield, California (BAK), and a nearby exurban population at the Naval Petroleum Reserves in California (NPRC). Our objective was to determine whether differences between urban and exurban environments, particularly food availability and disease vectors, were reflected in kit fox condition. Body mass, blood chemistry, and prevalence of viral antibodies were assessed at both sites in 1988 and 1989. Body mass was higher for BAK kit foxes, particularly juveniles, and varied between years for NPRC kit foxes. Higher red blood cell count (RBC), hemoglobin (Hb), hematocrit (Het), mean corpuscular hemoglobin (MCH), and mean corpuscular volume (MCV) among NPRC kit foxes were indicative of hemoconcentration, probably resulting from dehydration associated with low food or water intake. Kit forts from NPRC: exhibited higher blood urea nitrogen (BUN) and lower cholesterol (CHOL) levels compared to BAK kit foxes. These results may have reflected dietary differences, but they possibly indicated tissue catabolism by NPRC kit foxes due to nutritional deprivation. Other serological data also suggested nutritional stress among NPRC kit foxes. Prevalence of antibodies to canine parvovirus (CPV), canine distemper (CD), and infectious canine hepatitus (ICH) was similar between populations. Food availability for kit foxes at NPRC was relatively low during 1988-89 due to drought conditions, but food probably was not a limiting factor at BAK due to abundant water and the presence of anthropogenic foods. Urban environments may provide certain advantages for San Joaquin kit foxes and could contribute to conservation and recovery efforts.