Abstract - Behavioral Ecology of Dispersal in the Black-Tailed Prairie Dog

Garrett, Monte G. and Franklin, William L. 1988. Behavioral Ecology of Dispersal in the Black-Tailed Prairie Dog. Journal of Mammology 69. pp. 236-250.

Abstract

An investigation of black-tailed prairie dogs (Cynomys ludovicianus) wa conducted in Wind Cave National Park, South Dakota, between May 1979 and May 1982 to study factors affecting dispersal. Dispersing prairie dogs were radiotracked to determine distance of movements and survivorship, and a study colony was monitored intensively to determine proximate factors that caused dispersal. Exchange of individuals between coteries (family groups) within the study colony (intracolony dispersal) occurred throughout the year, whereas dispersal away from established colonies (intercolony dispersal) occurred only during a predictable period in late spring. Both males and females dispersed. Dispersing males were predominantly yearlings whereas dispersing females also included older individuals. Intercolony dispersers appeared to be in good physical condition, moved an average distance of 2.4 km from points of capture, and survivors immigrated into existing colonies; no new colonies were established by radiocollared animals. The mortality rate of intercolony dispersers was significantly greater than that among residents of the study colony. Prairie dogs select new vegetative growth at colony peripheries. Coterie density per ha of edge vegetation was inversely related to the exchange of individuals between coteries during the dispersal season. There was no relationship between absolute coterie density and change in animal numbers. Other factors promoting dispersal included shortage of unrelated females in the coterie; harassement of females by juveniles, and possible genetic influences.