COURTSHIP BEHAVIOR IN MALE RED-BACKED SALAMANDERS - THE ESS DATING GAME

Social interactions in red-backed salamanders, Plethodon cinereus, are complex and often depend upon the sex and reproductive status of indi viduals. In the population at Mountain Lake Biological Station, Virgin ia, adult males outnumber sexually active (gravid) females by approxim ately 2:1, because males court annually while females accept mates onl y biennially. Field observations of male P. cinereus suggest that male s maintain feeding territories and allow non-gravid (not sexually acti ve) females access to their territories for foraging, whereas they def end their territories against intrusion by males. We used a game-theor etic analysis of models of male fitness to examine conditions that wou ld favour the evolution of this 'permissive' behaviour. Under a series of increasingly realistic behavioural assumptions, we found that the critical factor in the evolution of male permissive behaviour is femal e preference for permissive males. If non-gravid females are more like ly to return to mate with a male that allows access to his territory, then permissive behaviour is likely to evolve. Furthermore, the evolut ion of permissive behaviour is facilitated when energetic losses due t o territorial defence exceed those due to allowing females to forage. (C) 1997 The Association for the Study of Animal Behaviour.