Mountain Ducks

Before passing to the final subfamily we may mention briefly the Mountain Ducks (Subfamily Merganettince), so called from their dwelling exclusively on the rushing mountain streams. They are medium-sized or small birds with narrow compressed bills as in the Mergansers, but differ from them in the absence of the tooth-like serrations on the edges of the mandibles, and in the rather long and stiff tail. Eight species are known, one in the mountain streams of New Zealand and the others in the rivers of the Andes. Of the New Zealand species (Hyrnenolcemus malacorhynchus) Buller says, "Far up the mountain gorge, where the foaming torrent, walled in on both sides, rushes impetuously over its shingle bed, surging around the huge water-worn boulders which obstruct its course, and forming alternately shallow rapids and pools of deep water, there the Mountain Duck is perfectly at home."