Breeding of Black Swan in Tasmania

Abstract

The breeding distribution of the Black Swan in Tasmania is given and the breeding history of the species over three years in the principal breeding area at Moulting Lagoon is described. The incubation period was found to be 39+ 2 days and cygnets fly 60 days after the appearance of juvenile plumage. Floods are the main source of egg mortality and other factors are relatively unimportant. Direct observation and statistical calculations were used to estimate the annual cygnet production. The statistical methods gave widely divergent estimates. Shooting over the breeding ground has an adverse effect upon breeding, upsetting pair formation. Restriction of this shooting has re1sulted in a greater cygnet production. Flooding and autodestruction of habitat are important factors in breeding success and recommendations for the management of the species are given.