New Zealand rock wren

The New Zealand rock wren (Xenicus gilviventris) is a small New Zealand wren (family Acanthisittidae) endemic to the South Island of New Zealand. Its Māori names include pīwauwau ("little complaining bird"), mātuitui, and tuke ("twitch", after its bobbing motion).[2] Outside New Zealand it is sometimes known as the rockwren or South Island wren to distinguish it from the unrelated rock wren of North America.

The rock wren is currently restricted to alpine and subalpine areas of the South Island; subfossil bones show it once lived in the North Island as well. 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 relative was the now-extinct bushwren. Its numbers are declining due to predation by introduced mammals.

New Zealand rock wren
NZ rock wren on rock
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Passeriformes
Family: Acanthisittidae
Genus: Xenicus
Species:
X. gilviventris
Binomial name
Xenicus gilviventris
Pelzeln, 1867

Description

Rock wren
Xenicis gilviventris, showing distinctive green, yellow, and grey colouring.

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.[3]

Distribution and habitat

This species is currently confined to alpine and subalpine zones (900–2500 m altitude)[4] of the Southern Alps, the Tasman Mountains of Northwest Nelson, and the Victoria Range of Westland, all in the South Island;[3] it is New Zealand's only truly alpine bird.[5] Subfossil remains suggest before Polynesian settlement it was also found in lowland forest and in the North Island. Its current alpine distribution is a habitat where few rodents can survive, full of sheltering rocks and dense vegetation.[6]

Bul01Bird250a
Rock wren nest

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;[3] instead, they seem to shelter and forage in rockfalls beneath the snow layer.[2]

Behaviour

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.[7] Its call is three high-pitched notes, and pairs sometimes duet.[3]

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, but including some kiwi, kakapo, kea, and kereru.[8] (Rock wrens are such assiduous collectors of feathers that their nests have been checked for kakapo feathers, to determine if those endangered parrots are in the area.)[2] 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.[2][3]

Rock wrens mostly eat invertebrates on the ground, but will sometimes take berries and seeds, and even nectar from flax flowers.[3]

Conservation

NZ Rock Wren among Rocks
Rock wren in its preferred habitat

Writing in the 1930s,[8] Herbert Guthrie-Smith declared,

Xenicus gilviventris, I am glad to think, is one of the species likely to survive changes that from the forester’s and field naturalist’s point of view have desolated New Zealand. The ravages wrought elsewhere by deer, rabbits, opossums, birds, and other imported vermin are unlikely to affect the welfare of the rock wren. Even weasels and rats — and I know they ascend to great heights — are hardly likely to draw sufficient recompense in prey from such unpeopled solitudes.… With cover and food supplies unmodified, the rock wren may be considered relatively safe.

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.[5][9] In the Murchison Mountains, rock wren showed a 44% decline in abundance over 20 years.[5] 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.[7] Predator trapping improved daily survival rates, egg hatching and fledgling rates of rock wrens.[10] 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.[2]

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.[2] In 2010 a survey located 12 unbanded rock wrens, indicating they were successfully breeding.[11]

References

  1. ^ BirdLife International (2012). "Xenicus gilviventris". IUCN Red List of Threatened Species. Version 2013.2. International Union for Conservation of Nature. Retrieved 26 November 2013.
  2. ^ a b c d e f Warne, Kennedy (June 2009). "The Also Wren". New Zealand Geographic (97): 80–91.
  3. ^ a b c d e f Heather, Barrie D.; Robertson, Hugh A. (2005). The Field Guide to the Birds of New Zealand. Auckland: Penguin. p. 374. ISBN 978-0-14-302040-0.
  4. ^ http://www.nzbirdsonline.org.nz/species/rock-wren
  5. ^ a b c Michelsen-Heath, Sue; Gaze, Peter (2007). "Changes in abundance and distribution of rock wren (Xenicus gilviventris) in the South Island, New Zealand". Notornis. 54 (2): 71–78.
  6. ^ Worthy, Trevor N.; Holdaway, Richard N. (2002). The Lost World of the Moa. Bloomington, IN: Indiana University Press. p. 425. ISBN 0-253-34034-9.
  7. ^ a b Gaze, Peter D. (2013). Miskelly, Colin M. (ed.). "Rock Wren". New Zealand Birds Online. Retrieved 6 April 2016.
  8. ^ a b Guthrie-Smith, Herbert (1936). Sorrows and Joys of a New Zealand Naturalist. Dunedin: A. H. & A. W. Reed.
  9. ^ "Rock wren sightings sought as figures fall". Otago Daily Times. 30 December 2008. Retrieved 30 December 2008.
  10. ^ Weston, K.A.; O’Donnell, C.F.J.; van dam-Bates, P.; Monks, J.M. (2018). "Control of invasive predators improves breeding success of an endangered alpine passerine". Ibis. 160 (4): 892–899. doi:10.1111/ibi.12617.
  11. ^ "New Zealand Rock wren thriving on new sanctuary". Wildlife Extra. Retrieved 6 April 2016.

Further reading

External links

Anchor Island

Anchor Island (Māori: Puke Nui) is an island in Dusky Sound in Fiordland.

The island is situated southwest of the much larger Resolution Island in the inlet area of Dusky Sound and surrounded by many smaller islands and contains four small lakes, including Lake Kirirua, the largest lake on an island in Fiordland.The island is part of the Fiordland National Park and since 2005 is one of few island sanctuaries that are home to the critically endangered kakapo (or night parrot).

Red deer and stoats had been eradicated between 2001 and 2005, and subsequently endangered endemic birds including tieke (saddleback), mohua (yellowhead), kakapo, and New Zealand rock wren have been relocated to the island. The island is one of only nine islands in the area that is completely free of introduced mammalian pests and is 2.5 km (1.6 mi) from the New Zealand mainland, which makes it relatively safe from repeat incursions by stoat and deer.

Fiordland National Park

Fiordland National Park occupies the southwest corner of the South Island of New Zealand. It is by far the largest of the 14 national parks in New Zealand, with an area of 12,607 square kilometres (4,868 sq mi), and a major part of the Te Wahipounamu World Heritage site. The park is administered by the Department of Conservation.

List of Late Quaternary prehistoric bird species

Late Quaternary prehistoric birds are avian taxa that became extinct during the Late Quaternary – the Holocene or Late Pleistocene – and before recorded history, or more precisely, before they could be studied alive by ornithological science. They became extinct before the period of global scientific exploration that started in the late 15th century. In other words, this list basically deals with extinctions between 40,000 BC and 1500 AD. For the purposes of this article, a "bird" is any member of the clade Neornithes, that is, any descendant of the most recent common ancestor of all currently living birds.

The birds are known from their remains, which are subfossil (not fossilized, or not completely fossilized). Some are also known from folk memory, as in the case of Haast's eagle in New Zealand. As the remains are not completely fossilized, they may yield organic material for molecular analyses to provide additional clues for resolving their taxonomic affiliations.

The extinction of the taxa in this list was coincident with the expansion of Homo sapiens beyond Africa and Eurasia, and in most cases, anthropogenic factors have played a crucial part in their extinction, be it through hunting, introduced predators or habitat alteration. It is notable that a large proportion of the species are from oceanic islands, especially in Polynesia. Bird taxa that evolved on oceanic islands are usually very vulnerable to hunting or predation by rats, cats, dogs or pigs – animals commonly introduced by humans – as they evolved in the absence of mammalian predators, and therefore have only rudimentary predator avoidance behavior. Many, especially rails, have additionally become flightless for the same reason and thus presented even easier prey.

Taxon extinctions taking place before the Late Quaternary happened in the absence of significant human interference. Rather, reasons for extinction are stochastic abiotic events such as bolide impacts, climate changes, mass volcanic eruptions etc. Alternatively, species may have gone extinct due to evolutionary displacement by successor or competitor taxa – it is notable for example that in the early Neogene, seabird biodiversity was much higher than today; this is probably due to competition by the radiation of marine mammals after that time. The relationships of these ancient birds are often hard to determine, as many are known only from very fragmentary remains and complete fossilization precludes analysis of information from DNA, RNA or protein sequencing.

The taxa in this list should be classified with the Wikipedia conservation status category "Prehistoric" in their individual accounts.

List of Passeriformes by population

This is a list of Passeriforme species by global population. While numbers are estimates, they have been made by the experts in their fields.

Passeriformes is the taxonomic order to which the perching birds belong.

List of birds by common name

In this list of birds by common name, a total of 9,722 extant and recently extinct bird species are recognised, belonging to a total of 204 families.

Long-billed wren (New Zealand)

The long-billed wren (Dendroscansor decurvirostris) was a species of New Zealand wren (family Acanthisittidae) endemic to the South Island of New Zealand. It was the only species in the genus Dendroscansor. The long-billed wren was a small bird with stout legs and tiny wings. Its reduced sternum suggests that it had weak flight muscles and was probably flightless, like the recently extinct Lyall's wren. Its weight is estimated at 30 g, which makes it heavier than any surviving New Zealand wren, but lighter than the also-extinct stout-legged wren. The bill of this species was both long and curved, unlike that of all other acanthisittid wrens.The species is known only from subfossils at four sites in Northwest Nelson and Southland; it seems to have been absent from the North Island and eastern South Island. The holotype was collected in 1986 from Moonsilver Cave, on Barrans Flat, near Takaka. It is the rarest fossil wren from New Zealand and presumably was the least common species when it was still extant. It is thought to have lived in high-altitude shrublands (like the surviving New Zealand rock wren) and perhaps montane southern beech forest.The long-billed wren went extinct before the arrival of European colonists and explorers in New Zealand. It was among the first wave of native bird species to go extinct after the introduction of Polynesian rats (or kiore). Like many New Zealand species, the long-billed wren presumably had few defences against novel predators such as rats.

New Zealand wren

The New Zealand wrens are a family (Acanthisittidae) 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 rock wren, being restricted to alpine areas. Both the remaining species are poor fliers and four of the five extinct species are known to be, or are suspected of having been, flightless (based on observations of living birds and the size of their sterna); along with the long-legged bunting from Tenerife, one of 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, are sedentary.

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

Passerine

A passerine is any bird of the order Passeriformes, which includes more than half of all bird species. Sometimes known as perching birds or – less accurately – as songbirds, passerines are distinguished from other orders of birds by the arrangement of their toes (three pointing forward and one back), which facilitates perching, amongst other features specific to their evolutionary history in Australaves.

With more than 110 families and some 6,409 identified species, Passeriformes is the largest order of birds and among the most diverse orders of terrestrial vertebrates. Passerines are divided

into three clades, Acanthisitti (New Zealand wrens), Tyranni (suboscines) and Passeri (oscine).The passerines contain several groups of brood parasites such as the viduas, cuckoo-finches, and the cowbirds. Most passerines are omnivorous, while the shrikes are carnivorous.

The terms "passerine" and "Passeriformes" are derived from the scientific name of the house sparrow, Passer domesticus, and ultimately from the Latin term passer, which refers to sparrows and similar small birds.

Xenicus

Xenicus is a genus of birds in the family Acanthisittidae. It contains New Zealand wrens.

Common
birds
Flightless
birds
Endangered
endemic birds
(flying)
Extinct
birds

This page is based on a Wikipedia article written by authors (here).
Text is available under the CC BY-SA 3.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.