Sexual Size Dimorphism in Desmognathine Salamanders

Abstract

Salamanders of the genus Desmognathus show an unusual form of sexual size dimorphism in which males are younger and smaller than females at first reproduction but surpass females in body size as they age. Data are presented that document this relationship for D. ochrophaeus, D. monticola, and D. quadramaculatus. The explanation for sexual size dimorphism in Desmognathus may reside in reproductive features that yield differences between the sexes in the relationship between body size and reproductive success; in particular, in older individuals, the rate of increase in reproductive success with body size is probably less in females than in males.