THE INFLUENCE OF EGG SURVIVORSHIP ON THE SUBSEQUENT NEST FIDELITY OF FEMALE BICOLOR DAMSELFISH, STEGASTES-PARTITUS

Abstract. In many animal species, females lay eggs within male territories. Research on female choice in such species has shown that females often assess male or territory quality indirectly on the basis of male characters that are correlated with male or territory quality. Researchers have given much less attention to the possibility that females can assess male or territory quality directly based on the survival of previous broods. This study demonstrates that in the bicolour damselfish, a species with exclusive male parental care of eggs, females use the survival of previously-laid eggs to avoid nests that have a low probability of offspring survival. Females mate repeatedly during a reproductive cycle and although they generally show high nest fidelity, this fidelity is broken when a nest loses an entire brood to nocturnally feeding brittlestars. Experimental removal of broods and addition of brittlestar odours to nests demonstrate that brittlestar odours are sufficient to cause females to avoid nests. Females may also respond to visual cues associated with brood loss. In addition, clutches laid in nests after nocturnal complete-brood losses are much less likely to survive than clutches laid in nests that have not suffered nocturnal complete-brood losses. Therefore, by avoiding nests from which brittlestars have recently removed eggs, females increase the probability of future egg survival.