Genetic Correlations and Matrilineal Structure in a Population of Spermophilus richardsonii

We analyzed nine matrilines within a single population of Richardson's ground squirrels (Spermophilus richardsonii) from southern Alberta, Canada, for genetic variability at six allozymic loci. Significant genetic differentiation was found among matrilines. The matrix of genetic distance between each pair of individuals was randomly associated with geographic distance, but matrices of genetic distance and coancestry, as well as coancestry and geographic distance, were significantly negatively correlated. Neighboring females tended to be more related than would be expected due to chance, not only within the entire population, but within individual matrilines as well. Correlation of coancestry and genetic distance values indicates that the predictability of kinship from genotypic data alone is unreliable. Female philopatry gives rise to non-random spatial and genetic associations of related individuals. This is the first documented genetic difference between matrilines for a sciurid species with a relatively low level of social complexity.