Body size and paternity in a teiid lizard (Ameiva exsul)

Male and female Ameiva exsul share overlapping home ranges. As a consequenc e sexually receptive females may have access to several males. We studied t he effect of relative male size on paternity in five experimental populatio ns of adult male and female A. exsul that were held in naturalistic 100 m(2 ) enclosures Each population, which initially consisted of three males and three females, was followed for a breeding season. Behavior was tallied fro m data gathered by focal animal observation, Progeny were obtained by harve sting clutches of eggs from the sand piles in which the animals denned, DNA samples from embryonic tissue and from blood of adults were compared to de termine parentage using RAPD-PCR with bands scored as dominant markers. Bod y size was strongly associated with male reproductive success in the enclos ures: the largest male in each enclosure sired the most progeny, and overal l, with enclosures as statistical blocks, large males shed significantly mo re progeny than did medium or small males. Nevertheless, small males obtain ed some paternity, and so were not completely excluded from reproduction. W e detected multiple paternity in one of the clutches.