Levels of Inbreeding Among Prairie Dogs

Abstract

Because inbreeding and outbreeding both involve distinct benefits, some optimal level of inbreeding-outbreeding should result under natural conditions. Testing this hypothesis has been difficult, mainly because the detailed pedigrees necessary for defining levels of inbreeding have been unavailable for animals other than humans. A 14-yr study of black-tailed prairie dogs (Cynomys ludovicianus) has shown that individuals avoid extreme inbreeding with close kin such as parents, offspring, and full and half siblings, but they regularly inbreed with more distant kin such as full and half first cousins, full and half first cousins once removed, full and half second cousins, and so on. Previous research with other wild animals has not documented such a high frequency of moderate inbreeding. An examination of five measures of reproductive success failed to reveal inbreeding depression.