Reproduction and Spacing Patterns of Kit Foxes Relative to Changing Prey Availability

Abstract

The occurrence of drought and a corresponding decline in the availability of the primary prey of San Joaquin kit foxes (Vulpes macrotis mutica) during 1990 and early 1991 provided a unique opportunity to document the effect of changing food resources on kit fox productivity and spacing patterns. Thus, we studied reproduction and spacing patterns of 38 kit foxes on a 110-km'study area of the Carrizo Plain Natural Area, California from December 1988 through November 1991. The primary effect of prey scarcity on kit foxes was to decrease reproductive success; none of 9 collared females reproduced in 1990. Home ranges of members of the same social group overlapped extensively (x = 70.0 ± 3.0 [SE]%, n = 20), whereas those of foxes in adjacent social groups overlapped only slightly (x = 14.0 ± 2.0%, n = 73)