Endangered
New Zealand rock wren
Xenicus gilviventris
The New Zealand rock wren is a small New Zealand wren (family Acanthisittidae) endemic to the South Island of New Zealand.
Appearance
Males are greenish with yellow flanks and a pale underside, females tend to be browner, although the degree of difference between the sexes varies geographically.
Its body length is typically about 9 centimetres (3.5 in). Males weigh around 16 g, females 20 g.
Published measurements include mass about 17.7.
Range and habitat
This species is currently confined to alpine and subalpine zones (900–2500 m altitude) of the Southern Alps, the Tasman Mountains of Northwest Nelson, and the Victoria Range of Westland, all in the South Island. It is New Zealand's only truly alpine bird. Subfossil remains suggest before Polynesian settlement it was also found in lowland forest. DNA from remains previously thought to be of North Island origin were compared with South Island wrens and found to be more closely related to the southern South Island clade.
The New Zealand rock wren is a small New Zealand wren (family Acanthisittidae) endemic to the South Island of New Zealand. The rock wren is currently restricted to alpine and subalpine areas of the South Island.
Pins are Wikidata “endemic to” fields. Orange dots, when present, are GBIF occurrence tiles — survey bias included.
Diet and breeding
Pairs maintain a year-round territory, and work together to build a large enclosed nest with an entrance tunnel. Guthrie-Smith recovered 791 feathers from one nest in the 1930s, most from weka, but among them some kiwi, kākāpō, kea, and kererū.
Rock wrens mostly eat invertebrates on the ground, but will sometimes take berries and seeds, and even nectar from flax flowers.
In crisis
The rock wren and rifleman are the only two surviving New Zealand wrens. The rock wren's closest relatives were the extinct stout-legged wrens, followed by the extinct bushwren. Its numbers are declining due to predation by introduced mammals. Since European settlement in the South Island, rock wrens have become more patchy in their distribution. A study of over 2,100 sightings between 1912 and 2005 showed the area they inhabit had declined significantly since the 1980s.
The main threats to rock wrens are stoats and mice, that eat their eggs and young: A 2012–13 study in the upper Hollyford showed that most rock wren nests were being preyed upon by stoats. Predator trapping improved daily survival rates, egg hatching and fledgling rates of rock wrens.
New Zealand rock wren is Endangered on this catalog because that is the IUCN category stored on Wikidata. Confirm the official criteria and any later count on iucnredlist.org.
Sources
Written for this catalog from the English Wikipedia article on New Zealand rock wren, Wikidata item Q135589. Family and order context is original field-guide writing about the group, not a copied assessment of this one species. Wikipedia text is CC BY-SA. Not an IUCN assessment. Counts, when quoted, can change — confirm them on the recovery programme and on iucnredlist.org.
