Influence of relatedness on snowshoe hare spacing behavior

Abstract

Predation and food are dominant forces regulating snowshoe hare (Lepus americanus) population density, yet manipulations of these factors have not proven sufficient to explain all aspects of hare population dynamics. Social interactions among hares have often been dismissed as unimportant in population regulation, but the mechanisms and consequences of such interactions have not been well studied. In this study, we examined one aspect of social behavior in snowshoe hares that has been hypothesized to be important in the spacing behavior of other species of small mammals: interactions among related individuals. We sampled 68 hares on two 7.3-ha grids in the southwest Yukon Territory during a cyclic peak phase of population density and used livetrapping and radiotelemetry to quantify spacing behavior. Hares were genotyped at 7 microsatellite DNA loci, and relatedness (r) among individuals was estimated and correlated with spacing. Average relatedness was low on both grids (≤0) because very few close kin were present. Hares were not more or less likely to associate with kin than they were with nonkin. The results were similar when males, females, adults, and juveniles were considered together or separately and are thus consistent with a lack of sex-biased dispersal in snowshoe hares. Kin are not clustered in snowshoe hare populations, thus interactions among kin do not likely have a strong influence on hare spacing behavior. This study supports the idea that spacing behavior has little influence on hare population dynamics, at least during the peak phase of the cycle.