The New Zealand rock wren (''Xenicus gilviventris'') is a small New Zealand wren (

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Acanthisittidae)

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to the

South Island The South Island, also officially named , is the larger of the two major islands of New Zealand in surface area, the other being the smaller but more populous North Island. It is bordered to the north by Cook Strait, to the west by the Tasman ...

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...

. Its

Māori Māori or Maori can refer to: Relating to the Māori people * Māori people of New Zealand, or members of that group * Māori language, the language of the Māori people of New Zealand * Māori culture * Cook Islanders, the Māori people of the C ...

names include ("little complaining bird"), , and ("twitch", after its bobbing motion). Outside New Zealand it is sometimes known as the rockwren to distinguish it from the unrelated

rock wren The rock wren (''Salpinctes obsoletus'') is a small songbird of the wren family native to western North America, Mexico and Central America. It is the only species in the genus ''Salpinctes''. Description Measurements: * Length: 4.9-5.9 i ...

of North America. The rock wren is currently restricted to

alpine Alpine may refer to any mountainous region. It may also refer to: Places Europe * Alps, a European mountain range ** Alpine states, which overlap with the European range Australia * Alpine, New South Wales, a Northern Village * Alpine National Pa ...

and subalpine areas of the South Island. It is a poor flier and highly terrestrial, feeding in low scrub, open scree, and rockfalls. The rock wren and rifleman are the only two surviving New Zealand wrens; the rock wren's closest relatives were the extinct

stout-legged wren ''Pachyplichas'' is a genus containing two extinct species of New Zealand wren, a family of small birds endemic to New Zealand. Species * †'' P. yaldwyni'' (South Island stout-legged wren) – South Island, New Zealand * †'' P. jagmi'' (No ...

s, followed by the extinct

bushwren The bushwren (''Xenicus longipes''), also known as the mātuhituhi in Māori, was a very small and almost flightless bird that was endemic to New Zealand. It had three subspecies on each of the major islands of New Zealand, the North Island, S ...

. Its numbers are declining due to predation by introduced mammals.

Description

The rock wren is a very small, almost tailless bird that prefers to hop and run on its long legs, and uses its rounded wings to fly only short distances. Males are 16 g, females 20 g. 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.

Distribution 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 misidentified North Island specimen is attributed a mislabeling by the original collector. Its current alpine distribution is a habitat where few rodents can survive, full of sheltering rocks and dense vegetation. Their preferred habitat is close to the treeline, amongst rockfalls, scree, fellfield, and low scrub. Rock wrens, unlike many alpine birds, do not migrate to lower elevations in winter; instead, they seem to shelter and forage in rockfalls beneath the snow layer.

Behaviour

Nest of Rock-Wren (Xenicus gilviventris)

The rock wren is a poor flier, rarely flying more than 2 m off the ground or for distances of more than 30 m. It prefers to hop and run with distinctive bobbing and wing flicks. Its call is three high-pitched notes, and pairs sometimes duet. Pairs maintain a year-round territory, and work together to build a large enclosed nest with an entrance tunnel. The nest is lined with feathers, often from other species of birds. Guthrie-Smith recovered 791 feathers from one nest in the 1930s, most from

weka The weka, also known as the Māori hen or woodhen (''Gallirallus australis'') is a flightless bird species of the rail family. It is endemic to New Zealand. It is the only extant member of the genus ''Gallirallus''. Four subspecies are recognize ...

, but including some

kiwi Kiwi most commonly refers to: * Kiwi (bird), a flightless bird native to New Zealand * Kiwi (nickname), a nickname for New Zealanders * Kiwifruit, an edible berry * Kiwi dollar or New Zealand dollar, a unit of currency Kiwi or KIWI may also refe ...

, kākāpō,

kea The kea (; ; ''Nestor notabilis'') is a species of large parrot in the family Nestoridae found in the forested and alpine regions of the South Island of New Zealand. About long, it is mostly olive-green with a brilliant orange under its wings ...

, and kererū. (Rock wrens are such assiduous collectors of feathers that their nests have been checked for kākāpō feathers, to determine if those endangered parrots are in the area.) Around three eggs are laid in late spring and incubated for three weeks. Chicks take about 24 days to fledge and are fed for at least 4 weeks. Rock wrens mostly eat invertebrates on the ground, but will sometimes take berries and seeds, and even nectar from

flax Flax, also known as common flax or linseed, is a flowering plant, ''Linum usitatissimum'', in the family Linaceae. It is cultivated as a food and fiber crop in regions of the world with temperate climates. Textiles made from flax are known in ...

flowers.

Conservation

Writing in the 1930s, Herbert Guthrie-Smith declared, This was not to be. Since European settlement, 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. In the Murchison Mountains, rock wren showed a 44% decline in abundance over 20 years. The main threats to rock wrens are stoats and mice, which 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. The long-term effect of climate change on their alpine habitat is also a threat, as warmer temperatures will allow rats to move higher into the mountains. In 2008–2010, a total of 40 rock wrens were translocated to Secretary Island, an 8140 ha rodent-free island in Fiordland, the third-tallest island in New Zealand. In 2010 a survey located 12 unbanded rock wrens, indicating they were successfully breeding. The rock wren was voted New Zealand Bird of the Year for 2022.

References

External links

* New Zealand rock wren discussed on

RNZ Radio New Zealand ( mi, Te Reo Irirangi o Aotearoa), commonly known as Radio NZ or simply RNZ, is a New Zealand public-service radio broadcaster and Crown entity that was established under the Radio New Zealand Act 1995. It operates news and cu ...