 The huia belonged to a family found only in New Zealand. Before the arrival of Europeans it was already a rare bird, confined to the Ruahine, Tararua, Rimutaka and Kaimanawa mountain ranges in the south east of the North Island. It was remarkable for having the most pronounced sexual dimorphism in bill shape of any bird species in the world. The female's beak was long, thin and arched downward, while the male's was short and stout, like that of a crow. Males were 45 cm (18 in) long, while females were larger at 48 cm (19 in). The sexes were otherwise similar, with orange wattles and predominantly black plumage with a green sheen. The birds lived in forests at both montane and lowland elevations – they are thought to have moved seasonally, living at higher elevation in summer and descending to lower elevation in winter. Huia were omnivorous and ate adult insects, grubs and spiders, as well as the fruits of a small number of native plants. Males and females used their beaks to feed in different ways: the male used his bill to chisel away at rotting wood, while the female's longer, more flexible bill was able to probe deeper areas.
