The speculum has thin black then slightly broader white edges at front and rear. The secondary flight feathers are metallic blue, forming a ‘speculum’ on the trailling edge of the inner upper-wing. The back and flanks are pale grey, and the rump and undertail blackish, with curled black upper tail coverts. In breeding plumage, drakes have the head and neck glossy dark green, separated from the maroon breast by a thin white collar. Drakes are about 10% larger than females. Mallards are the ducks that gather en masse whenever bread is thrown out at an urban pond. As a consequence of both their gamefarm origin and hybridisation, the plumages of New Zealand’s mallards are highly variable, especially the females, and males in breeding plumage are duller and less striking than wild northern hemisphere mallards. Extensive hybridisation with the native grey duck followed soon after their initial release and the mallard competitively excluded grey ducks from most wetlands, especially those in and near urban environments and in pastoral landscapes. Acclimatisation Societies subsequently bred and released over 30,000 mallards throughout New Zealand until 1974, by which time the mallard had become the most common waterfowl in the country. The New Zealand mallard population is derived from 17 small importations of gamefarm mallards from England between 18, and two later imports of birds and eggs from a gamefarm in Connecticut, USA.
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