MORPHOMETRIC COMPARISON OF 2 SYMPATRIC GOSHAWKS FROM THE AUSTRALIAN WET TROPICS

Sympatric populations of the grey goshawk Accipiter novaehollandiae and the brown goshawk Accipiter fasciatus were studied in the wet tropics of north-eastern Australia. The morphology of A. novaehollandiae suggests that it is adapted for life in dense forest, while that of A. fasciatus indicates that it should favour open woodland. The species differ in the shape of the wing and the size and shape of feeding structures. The wings of A. novaehollandiae are relatively short and broad, its bill and talons are more robust and its tarsi are relatively short and thick. It appears to be adapted to feed on medium-sized mammals and reptiles and on larger birds such as pigeons and megapodes. A. fascialus has relatively longer and narrower wings, allowing greater speed in open habitats. Its more delicate bill and longer tarsi are characters typical of bird-eating accipiters.