Comparisons of Displaced and Retained Partners in a Monogamous Lizard

摘要

A population of the skink Trachydosaurus rugosus from near Mt Mary, South Australia, was studiednover 7 years. The lizards are usually solitary, but form pairs for about 8 weeks in spring before mating.nPairs showed a high degree of fidelity both within and between years. Males which were displaced asnpartners were significantly smaller than those which were retained as partners, although no differentnin size from the males which replaced them. For females in pairs there was no difference in size betweenndisplaced and retained individuals. Those lizards that were displaced were as likely as retained partnersnto survive, as measured by recaptures in subsequent years. The lizard population probably containsnlarger, older males with established pair bonds, and smaller younger, males exchanging females whilenfighting to establish such bonds. This is not unusual in animal populations, but it is the first case ofnsuch a system reported in reptiles.