New Zealand Wren

New Zealand Wren

Acanthisitta
Xenicus
Pachyplichas
Dendroscansor

The New Zealand wrens, Acanthisittidae, are a family of tiny passerines endemic to New Zealand. They were represented by six known species in four or five genera, although only two species survive in two genera today. They are understood to form a distinct lineage within the passerines, but authorities differ on their assignment to the oscines or suboscines (the two suborders that between them make up the Passeriformes). More recent studies suggest that they form a third, most ancient, suborder Acanthisitti and have no living close relatives at all. They are called "wrens" due to similarities in appearance and behaviour to the true wrens (Troglodytidae), but are not members of that family.

New Zealand wrens are mostly insectivorous foragers of New Zealand’s forests, with one species, the New Zealand Rockwren being restricted to alpine areas. Both the remaining species are poor fliers and four of the five extinct species are known to or are suspected of having been flightless (based on observations of living birds and the size of their sternum); along with the Long-legged Bunting from the Canary Islands they are the only passerines known to have lost the ability to fly. Of the species for which the plumage is known they are drab coloured birds with brown-green plumage. They form monogamous pair bonds to raise their young laying their eggs in small nests in trees or amongst rocks. They are diurnal and like all New Zealand passerines for the most part sedentary.

New Zealand wrens, like many New Zealand birds, suffered several extinctions after the arrival of humans in New Zealand. Two species went extinct after the arrival of the Māori and the Polynesian Rat, and are known today only from fossil remains; a third, the Stephen's Island Wren went extinct on the main islands, surviving only as a relict population on Stephens Island in the Cook Strait. Two species, the Stephens Island Wren and the Bush Wren, became extinct after the arrival of Europeans, with the Bush Wren surviving until 1972. Of the two remaining species the Rifleman is still common on both North and South Island, while the New Zealand Rockwren is restricted to the alpine areas of South Island and is considered vulnerable.