Anas superciliosa

General description: 

Mostly mid-brown in colour, with each feather edged buff. The head pattern is characteristic, with a dark brown line through the eye, bordered with cream above and below and a dark brown crown. The upper wing colour is the same as the back, with a bright glossy green patch in the secondary flight feathers. The white underwing is conspicuous in flight. Young Pacific Black Ducks are similar to the adults in plumage.

Conservation status: 

Not Threatened.

Diagnostic description: 

Mostly mid-brown in colour, with each feather edged buff. The head pattern is characteristic, with a dark brown line through the eye, bordered with cream above and below and a dark brown crown. The upper wing colour is the same as the back, with a bright glossy green patch in the secondary flight feathers. The white underwing is conspicuous in flight. Young Pacific Black Ducks are similar to the adults in plumage.

Behaviour: 

Size: 

50-60 cm

Phylogeny: 

Taxonomy:

    Anas superciliosa Gmelin, 1789, New Zealand. Often included in A. poecilorhyncha. Form superspecies with A. poecilorhyncha and A. luzonica. Probable unstable hybrids of present species and A. platyrhynchos, found on some Micronesian islands, have been considered a different species, Mariana Duck (A. oustaleti). Hybridization with several species of genus Anas recorded in captivity, and with A. platyrhynchos, producing fertile progeny, in the wild; in New Zealand over 25% of populations may be hybrids. Validity of poorly defined subspecies has been questioned. Three subspecies recognized. (source: Handbook of the Birds of World)
Distribution: 

Subspecies and Distribution:

    *pelewensis Hartlaub & Finsch, 1872 - SW Pacific Is, N New Guinea.*rogersi Mathews, 1912 - Indonesian region, S New Guinea, Australia. *superciliosa Gmelin, 1789 - New Zealand and larger offshore islands.
Habitat: 

It frequents all types of water, from isolated forest pools to tidal mudflats. Pacific Black Ducks are usually seen in pairs or small flocks and readily mix with other ducks. In the wild, birds are often very wary of humans and seldom allow close approach. Birds in urban ponds become quite tame, however.

Trophic strategy: 

Mainly vegetarian, feeding on seeds of aquatic plants. This diet is supplemented with small crustaceans, molluscs and aquatic insects. Food is obtained by 'dabbling', where the bird plunges its head and neck underwater and upends, raising its rear end vertically out of the water. Occasionally, food is sought on land in damp grassy areas.

Reproduction: 

Mating in Pacific Black Ducks coincides with availability of sufficient food and water, and often with the onset of heavy rains or when waterways are at their peaks. Courtship is accompanied by ritualised displays including preening, bobbing and wing-flapping. This behaviour is often initiated by the female, and, other than copulation, the male helps little in the breeding process. Often, two broods will be raised in a year. The number of offspring produced may seem quite high, but only 20% of these will survive past two years of age.