ANAS SUPERCILIOSA - (GMELIN, 1789)
Le Canard à sourcils ou Pacific Black Duck (Anas superciliosa) est une espèce de canards de surface trouvé en Indonésie, Nouvelle-Guinée, Australie, Nouvelle-Zélande, dans le sud-ouest de l'océan Pacifique, jusqu'aux îles Caroline au nord et à la Polynésie française à l'est.
Il mesure 54 à 61 cm de long, le mâle étant un peu plus grand que la femelle. C'est un canard au plumage foncé avec une tête un peu plus pâle et des traits sur la face; le ventre est plus pâle. Dans certaines îles, cette espèce est de taille plus petite et a un plumage plus foncé.
On le trouve dans nombre d'habitats humides et il a les mêmes habitudes pour nicher que le canard colvert qui empiète sur son domaine en Nouvelle-Zélande.
Il se nourrit en basculant et en plongeant la moitié antérieure de son corps sous l'eau.
The Pacific Black Duck (Anas superciliosa) is a dabbling duck found in much of Indonesia, New Guinea, Australia, New Zealand, and many islands in the southwestern Pacific, reaching to the Caroline Islands in the north and French Polynesia in the east. It is usually called the Grey Duck in New Zealand. It is also known in New Zealand by its Maori name, Parera.
This sociable duck is found in a variety of wetland habitats, and its nesting habits are much like those of the Mallard, which is encroaching on its range in New Zealand. It feeds by upending, like other Anas ducks. It has a dark body, and a paler head with a dark crown and facial stripes. In flight, it shows a green speculum and pale underwing. All plumages are similar. The size range is 54–61 cm; males tend to be larger than females, and some island forms are smaller and darker than the main populations. It is not resident on the Marianas islands, but sometimes occurs there during migration. The now extinct Mariana Mallard was probably originally derived from hybrids between this species and the mallard, which came to the islands during migration and settled down there. There are three subspecies of Anas superciliosa : Rogersi - (Mathews, 1912) Australasian Duck, breeds in Indonesia, southern New Guinea and Australia. - pelewensis - (Hartlaub & Finsch, 1872) - Island Black Duck, breeds on the southwest Pacific islands and northern New Guinea. - superciliosa (Gmelin, 1789) - New Zealand Grey Duck, breeds in New Zealand. The New Zealand subspecies has declined sharply in numbers, at least in its pure form, due to competition from and hybridisation with the introduced mallard. Rhymer et al. (1994) say their data "points to the eventual loss of identity of the Grey Duck as a separate species in New Zealand, and the subsequent dominance of a hybrid swarm akin to the Mariana Mallard." It was assumed that far more mallard drakes mate with Grey Duck females than vice versa based on the fact that most hybrids show a mallard-type plumage, but this is not correct; it appears that the mallard phenotype is dominant, and that the degree to which species contributed to a hybrid's ancestry cannot be determined from the plumage. The main reasons for displacement of the Parera seem to be physical dominance of the larger mallards, combined with a marked population decline of the Parera due to overhunting in the mid-20th century.