Patterns of genetic variation and parentage in a population of desert kit foxes (Vulpes macrotis arsipus) in California

Abstract

Kit foxes represent a small canid in semi-arid and arid regions in the southwestern United States. The San Joaquin Kit Fox (Vulpes macrotis mutica) is listed as federally endangered, and based on more recent studies, populations of the Nevada Kit Fox (V. m. nevadensis) are declining in Utah. These 2 subspecies show a loss of genetic variation in response to population declines. Various anthropogenic activities threaten kit foxes throughout other regions of their distribution, but less is known about the basic biology and genetics of other subspecies of kit foxes. Here, we used sequences from the mitochondrial cytochrome b (Cytb) gene and 12 DNA microsatellites to investigate patterns of genetic variation and test for mating fidelity in a population of the socially monogamous Desert Kit Fox, V. m. arsipus. In the current study, the mitochondrial haplotype diversity (Hd) was higher than or comparable to other canids and terrestrial mammals. The mitochondrial results also provided evidence for male-biased dispersal and female philopatry. Expected heterozygosity (He) and number of alleles per locus (Na) for the 12 microsatellite loci were higher relative to other species of foxes and canids. As seen for nearly all species of socially monogamous canids, 17% of the pups of the mated pairs of the Desert Kit Fox revealed evidence of extra-pair mating, a value like small canids. Additionally, we observed 1 case of mate switching between breeding seasons, even though the previous mate was still alive. These data suggest that long-term pair bonding may not be as extensive as once thought.