Rock Wren

Pīwauwau is a tiny, short-tailed bird of South Island alpine basins and the only New Zealand bird that remains above the bush line throughout the year. It moves through rocks by hopping and running, with frequent body bobs and wing flicks. Males are dull green above with grey-brown underparts and yellow flanks; females are plainer olive-brown. Rifleman has a longer, more upturned bill and occupies forest rather than the exposed alpine habitat of pīwauwau.

Populations are scattered through the Southern Alps from Fiordland and Mount Aspiring to Aoraki/Mount Cook, Arthur’s Pass, Nelson Lakes and Kahurangi national parks. Birds occupy rocky and scrubby sites about 900–2,500 m above sea level. Pīwauwau pick moths, larvae, flies, beetles and spiders from boulders and alpine plants, and also eat Coprosma and Gaultheria fruit. A pair builds a feather-lined enclosed nest in a ground cavity and usually raises one brood from a clutch averaging about three eggs.

Pīwauwau is Threatened — Nationally Endangered (NZ Threat Classification). Stoats and mice raid its ground nests, and isolated alpine populations can disappear locally. The Otira Valley at Arthur’s Pass and accessible alpine valleys in Fiordland, Mount Aspiring and Aoraki/Mount Cook national parks offer chances of sightings. Listen for a high three-note call and watch low boulderfields for a bobbing bird.