Urban Roads and the Endangered San Joaquin Kit Fox

Abstract

The San Joaquin kit fox is at risk of extinction primarily due to profound habitat degradation, fragmentation, and loss. However, kit foxes inhabit some urban areas, and roads present a potential threat to kit foxes in these areas. From 1998-2004, the authors investigated the effects of roads on urban kit foxes in Bakersfield, California. Vehicles were the primary cause of mortality for urban kit foxes, and most strikes occurred on arterial roads, which had higher traffic volumes and speed limits. Also, foxes were more frequently struck near intersections between major roads and other linear rights-of-way (e.g., railroads, canals, other roads), which likely were used as travel corridors by kit foxes. Males appeared to be particularly vulnerable to vehicle strikes during the winter mating season. Kit foxes did not appear to avoid roads when selecting den sites. During nocturnal activity periods, kit foxes commonly crossed local roads, but less frequently crossed arterial or collector roads. Roads impact urban kit foxes through reduced survival, occasional den loss, inhibited movements, and habitat loss. When conducting road projects (e.g., construction, maintenance), the California Department of Transportation (Caltrans) implements standard measures to minimize impacts to kit foxes. The authors recommend the implementation of additional measures, specifically the installation of artificial dens and road crossing structures, to further minimize impacts. Implementation of these measures will facilitate conservation of urban kit foxes and contribute to range-wide recovery.