Behavior of the Australian Musk Duck and Blue-Billed Duck

Abstract

THE stiff-tailed ducks include a group of nine species currently placed in four genera (Delacour, 1959), of which only two (Oxyura and Biziura) possess the elongated and stiffened rectrices for which the group is named. Biziura is monotypic and consists of the Australian Musk Duck (B. lobata), but Oxyura includes six species which are widely distributed on all continents and is represented in Australia by the Blue-billed Duck (0. australis). Intrageneric relationships and species limits in Oxyura are still somewhat uncertain (cf. Delacour and Mayr, 1945, with Delacour, 1959), due to considerable external uniformity among most species and limited comparative information. Because of these taxonomic uncertainties and the fact that the stiff-tailed ducks tend to have highly varied and elaborate displays, a comparative study of their behavior patterns has been undertaken in hopes of better interpreting relationships in the group. As a first step in that study, the two Australian representatives were investigated in July and August of 1964, and the present paper summarizes my behavioral observations on these species. Some additional observations on the general behavior, vocalizations, and abundance of these and other species are published elsewhere (Johnsgard, 1965).