Mortality of San Joaquin kit fox (Vulpes velox macrotis) at Camp Roberts Army National Guard Training Site, California

Abstract

Sources and rates of mortality of a San Joaquin kit fox population (Vulpes velox macrotis) were investigated at Camp Roberts Army National Guard Training Site, California, from November 1988 through September 1991. National Guard-authorized activities, including military training, caused the death of three of the 94 (3%) kit foxes radiocollared, and do not appear to jeopardize the continued existence of the population. Predation by larger carnivores, primarily coyotes (Canis latrans), caused the death of 75% of the 32 radiocollared kit foxes recovered dead for which a cause of death could be determined; vehicle impacts, disease (rabies), poisoning, and shooting were each responsible for the deaths of 6.3%. Adult annual mortality rate was 0.47 and the juvenile mortality rate was 0.80, and both rates are similar to rates reported for kit foxes in other locations. There was no significant difference between male and female mortality rates in either age class. The proportions of dead kit foxes recovered in different habitat types were similar to the availability of the habitat types within the distribution of kit fox on the installation.