Musk Duck brood parasitism on Black Swans

Abstract

This paper describes incidences of brood parasitism of nests of Black Swans Cygnus atratus by Musk Ducks Biziura lobata. Black Swans have a long incubation period, and as they are unlikely to exhibit egg rejection behaviour, they are potentially suitable as hosts for Musk Duck parasitism. Model eggs were used to test whether the success of brood parasitism in this system is constrained by host responses (egg recognition or nest abandonment), or egg shell strength. The results showed that Black Swans readily accept foreign eggs, even when they are very different from their own. However, there was a substantial loss of weak-shelled model eggs, thought to be accidentally crushed by the swans. T..