Competition and waste in the communally breeding smooth-billed ani: effects of group size on egg-laying behaviour

We investigated the effects of group size on egg-laying behaviour in the communally breeding, joint-nesting smooth-billed ani, Crotophaga ani. We tested the predictions of the competitive female egg-investment hypothesis, which states that females in plurally breeding, joint-nesting systems respond to increased group size and egg-laying competition by trying to skew the contents of the final incubated clutch of eggs in their own favour by …