If reproduction impairs an organism's ability to perform other fitness-related activities, natural selection may favour behavioural adjustments to minimize these conflicts. This is presumably the reason why many animals are anorexic during the breeding season. We studied amphibious sea snakes, a group whose ecology facilitates teasing apart the causal links between reproduction and feeding. In both Laticauda laticaudata and L. saintgironsi in New Caledonia, adult females cease feeding as their eggs develop. The advantages of foregoing feeding do not relate to thermoregulation (because foraging does not entail lower body temperatures), nor are they attributable to physical constraints on abdominal volume (because in a snake's linear body, there is little overlap between the stomach and the oviducts). Instead, female sea kraits appear to cease feeding because their bodily distension impedes locomotor ability, rendering them less effective at foraging and more vulnerable to aquatic predators.
- bodily distension
- sea snake