Molecular genetic perspective of group-living in a polygynous fruit bat, Cynopterus sphinx

In this study, we investigated the genetic social structure of a polygynous fruit bat, Cynopterus sphinx. We tested whether colonies of C. sphinx are substructured and if genetic relatedness among group members is non-random. Although we did not find statistical evidence of genetic structuring of harems within a colony, significant levels of inbreeding within colonies and social associations between related individuals were observed. The average pairwise relatedness was higher for females within a harem (average: 0.02) than within the colony (average: −0.03) (p < 0.005). In most harems, the harem male was highly related to one harem female (with an average relatedness of 0.2). Further, statistical resampling suggested that this association is non-random, potentially suggesting mate selection. Although the average relatedness among males in colonies was zero, the range of relatedness (−0.43 to 0.49) was high. We conclude that colonies, to some extent are inbred units, comprising of both related and unrelated individuals, and that social associations might be kin based.