Evidence for Male-biased Dispersal in Bobcats Lynx Rufus Using Relatedness Analysis

Abstract

Dispersal is a mechanism hypothesized to have evolved to reduce resource competition, competition for mates and inbreeding. Although bobcats Lynx rufus are believed to exhibit high dispersal rates, bobcat dispersal has not been extensively studied due to limitations associated with traditional field research methods. We examined dispersal patterns in a southern Texas bobcat population using eight microsatellites by estimating relatedness within the population and among individuals and observing dispersal events via radio-telemetry. Relatedness among females (r = 0.050, ± 0.042, 95% CI) was significantly higher than among males (r = -0.075, ± 0.031). Pair-wise relatedness distribution for females was significantly different from the expected random distribution and skewed towards 1st and 2nd degree relatives. In contrast, pair-wise relatedness distribution for males was not significantly different from the expected random distribution. Male-biased dispersal and female philopatry were hypothesized to explain the observed patterns in relatedness. Among nine radio-collared females and 12 radio-collared males, two females and six males dispersed away from the study site. This study provides genetic and observational evidence for male-biased dispersal in a solitary felid and is consistent with dispersal trends in mammals.