The systematic status of the Cape Barren Goose as judged by its photo-responses

Abstract

The median date of egg-laying of various wildfowl species in the Wildfowl Trust's collection at Slimbridge, England, is plotted against the mid-latitude of their natural breeding range. The result for the Cape Barren Goose Cereopsis novaehollandiae is closer to the pattern for the swans than to that of the true geese or the sheldgeese. An evolutionary tree placing Cereopsis closer to the swans than to any living goose or sheldgoose species and perhaps closer to the ancestral Anatidae stock is proposed.