Hoogland, John L. 1981. Nepotism and Cooperative Breeding in the Black-tailed Prairie Dog (Sciuridae: Cynomys ludovicianus). In Alexander, Richard D. and Tinkle, Donald W. Natural Selection and Social Behavior, Recent research and new theory.

Abstract

Cooerative breedign occurs whenever certain individuals relinquish their own breeding and assist the breeding of others (Brown, 1974, 1978). As emphasized by Emlen (1978), explaining cases of apparent altruism (alexander, 1974; Wilson, 1975) such as cooperative breeding is one of the most important issues faced by evolutionary biologists. Cooperativer breeding is especially common among the social insects (Wilson, 1971) but also occurs in numerous vertebrate. Studies of cooperative breeding species have usually shown that nonbreeding, cooperating individuals ("helpers at the nest" or "allo-parents") are genetically related to the breeding adults. Theories to explain cooperative breeding have nonetheless been numerous and diversified (e.g., Fry., 1972; Gaston, 1976,1978; Zahavi, 1976; Brown, 1978; Emlen, 1978; Woolfenden and Fitzpatrick, 1978). In this report, I investigate cooperative breeding in the black-tailed prairie dog (Cynomys ludovicianus). My purpose is twofold: (a) to examine the genetic relationships among the members of a cooperatively breeding unit known as a coterie, (b) to quantify alarm calling and both intrs- and inter- coterie interactions (fights, chases, allogrooming, etc.), and to determine if these behaviors involve preferential treatment of genetic relatives, (c) to examine the effect of coterie size on annual reproductive success of adult males and females, and (d) to examine several relevant hypotheses that might explain the observed relationship between coterie size and the annual reproductive success of adult females.