Prairie Dogs Disperse When All Close Kin Have Disappeared

Still Living in Their Mother's House Dispersal, movement away from an organism's natal site, is a critical stage in the development of a juvenile into an adult and several drivers of this process have been proposed. A classic hypothesis put forward by Hamilton and May argues that individuals disperse away from kin in order to avoid competing with similar phenotypes. Many species have been shown to follow this pattern, and it is generally accepted that most organisms disperse well away from the sites where they were born. However, not all species follow this pattern and some display a distinct tendency to remain within their mother's home range. Hoogland (p. 1205 ) studied populations of three species of prairie dogs over more than three decades and found that the presence of close kin in these highly social rodents actually led young animals to remain on their natal site, whereas dispersal away from it occurred almost exclusively when close female kin were absent. This suggests that sociality may in fact result in individuals remaining with their close kin in order to benefit from cooperation and that longer-distance dispersal may instead occur when the opportunity for cooperation does not exist.