Kinship social relationships, and den sharing in kit foxes

We used 11 microsatellites, highly variable nuclear markers, to infer kinsh ip among 35 San Joaquin kit foxes,Vulpes macrotis mutica, and combined this information with field observations to gain insight into fox social behavi or. Fox social units consisted of solitary foxes, mated mate-female pairs, and trios consisting of a mated pair plus another adult. Pair-mates were no t closely related. The additional adult (1 male, 1 female) in 2 trios was t he offspring of at least 1 of the pair-mates. Foxes living on adjacent home ranges tended to be more closely related than foxes that did not live on a djacent home ranges, largely because females on adjacent home ranges were o ften closely related. F-IS values indicated a deficiency of homozygotes tha t was likely due to clusters of relatives living on adjacent home ranges. F oxes that shared the same den on the same day were usually members of the s ame social group. Contrary to expectations, however, we sometimes found fox es sharing dens with foxes from other social groups. Many cases involved un paired individuals and appeared to be unsuccessful attempts at pair formati on. Other cases involved members of 2 adjacent social groups, a pair and a trio. Both members of the pair were closely related to 1 member of the trio , indicating that kit foxes can maintain enduring social relationships with adult offspring or siblings that have dispersed to a new home range and fo und a mate.