SREL Reprint #2299

Breeding groups and gene dynamics in a socially structured population of prairie dogs

F. Stephen Dobson1, Ronald K. Chesser2,3, John L. Hoogland4, Derrick W Sugg2, and David W. Foltz5

1Department of Zoology and Wildlife Science, Auburn University, Auburn, AL 36849
2University of Georgia, Savannah River Ecology Laboratory, Aiken, SC 29802
3Department of Genetics, University of Georgia, Athens, GA 30602
4Appalachian Environmental Laboratory, University of Maryland, Frostburg, MD 21532
5Department of Zoology and Physiology, Louisiana State University, Baton Rouge, LA 70803

Abstract: Genetic substructuring of a colony of black-tailed prairie dogs (Cynomys ludovicianus) was examined using three different sources of information: allozyme alleles, pedigrees, and demography (a "breeding-group" model based on mating and dispersal patterns). Prairie dogs and their social breeding groups (called "coteries") were studied under natural conditions during a 15-year period. Prairie-dog coteries exhibited substantial genetic differentiation, with 15-20% of the genetic variation occurring among coteries. Mating patterns within the colony approximated random mating, and, thus, mates tended to originate from different coteries. Social groups of black-tailed prairie dogs resulted in genetic substructuring of the colony, a conclusion that was supported by estimates from allozyme alleles and colony pedigrees. Predictions of the breeding-group model also were consistent with and supported by estimates from allozyme and pedigree data. Some methodological problems were revealed during analyses. Although individuals of all ages usually are pooled for biochemical estimates of among-group genetic differentiation, our estimates of among coterie variation from allozyme data were somewhat higher for young than for older prairie dogs, perhaps due to sampling effects caused by mating patterns and infanticide of offspring. Pedigree estimates of among-coterie genetic differentiation were significantly positive for young prairie dogs, adult females, and adult males. Those estimates were always more accurate for the offspring generation, however, because pedigree data were always more complete for young and genetic differences among coteries were diluted by virtually complete dispersal of males away from their natal coteries.

Keywords: allozymes, breeding groups, demography, gene dynamics, pedigrees, black-tailed prairie dogs

SREL Reprint #2299

Dobson, F.S., R.K. Chesser, J.L. Hoogland, D.W. Sugg, and D.W. Foltz. 1998. Breeding groups and gene dynamics in a socially structured population of prairie dogs. Journal of Mammalogy 79:671-680.

This information was provided by the University of Georgia's Savannah River Ecology Laboratory (srel.uga.edu).