Waiting for Nemo

Abstract

ECOLOGY/EVOLUTION In some animal societies, a group can consist of both breeding and nonbreeding adults. In such cases, non-breeders often achieve breeding status through sneak matings, through the demotion or demise of the dominant individual(s), or by dispersing to another group. Buston has documented a case of the “perfect queue,” in which subordinate individuals replace successive dominants without dispersal and without a fight. The clownfish Amphiprion percula inhabits the tentacles of sea anemones in small size-ranked groups of up to six individuals, with a single breeding pair. Newcomers to the group join as larval settlers and ascend toward breeding status as individuals die further up the dominance hierarchy; queue-jumping by dispersal or contest is never observed. This patient behavior appears to maximize an individual's probability of assuming the breeding territory; in other words, nonbreeding status is tolerated because it confers a potential to realize future benefits. — AMS Proc. R. Soc. London Ser. B 10.1098/rsbl.2003.0156 (2004).