Te Kakahu skink

Last updated

Te Kakahu skink
Chalky Island Te Takahu skink by Hannah Edmonds-DOC.jpg
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Squamata
Family: Scincidae
Genus: Oligosoma
Species:
O. tekakahu
Binomial name
Oligosoma tekakahu
Chapple, Bell, Chapple, Miller, Patterson & Daugherty, 2011
Synonyms
  • Oligosoma inconspicuum ‘Te Kakahu’
  • Oligosoma sp. 6 (Te Kakahu skink)

The Te Kakahu skink (Oligosoma tekakahu) is a critically endangered species of skink native to New Zealand. When discovered, the entire species was inhabiting a single patch of clifftop vegetation on Chalky Island in Fiordland National Park.

Contents

Discovery

The Te Kakahu skink was discovered in 2002 by members of the Department of Conservation (DOC) kākāpō recovery team. [2] Sixteen skinks were collected in 2008, and the species was formally described in 2011 and named Oligosoma tekakahu. [3]

Its species name, tekakahu, comes from the Māori name of Chalky Island, Te Kākahu-o-Tamatea , or "Tamatea's cloak", referring to the oral tradition that this island was where the explorer Tamatea dried his cloak after being drenched by the sea. Although the Māori word kākahu or cloak is spelled with a macron, [4] the skink's name is usually spelled without. [5]

Appearance

Although very similar to the cryptic skink (O. inconspicuum) and the southern skink (Oligosoma notosaurus), the Te Kakahu skink is genetically distinct. [6] It is sturdier and has a comparatively larger head than other related Oligosoma species in the cryptic-skink complex. [7] It is predominantly chestnut brown and glossy with small black markings on its back – either individual flecks or the trace of a mid-dorsal stripe – and a darker stripe down each side. [8] One distinguishing feature are the minimal projecting scales on the interior edge of its small ear opening. [5]

Habitat

This species is recorded as inhabiting just one small site above windswept chalk cliffs on the northwestern coast of Chalky Island, about 130–140 m above sea level. [6] [2] Known as "the blowout", this stony area has had most of the soil removed by wind and only has low vegetation. The skinks are centred on a 50 m² patch of low scrub, mostly sedges ( Carex ), Rytidosperma , and the low-growing shrubs Olearia avicennifolia and O. oporina . [3]

Stoats were not eradicated from the island until 1999, so this is likely to be a last refuge from which the skink population is now expanding. [9] [3] It is possible this species still exists in similar habitat on nearby islands or the mainland. [10]

Conservation status

Te Kakahu skink (Oligosoma tekakahu) on Chalky Island Chalky island skink by Erina Loe, DOC.jpg
Te Kakahu skink (Oligosoma tekakahu) on Chalky Island

In 2012 the Department of Conservation reclassified the Te Kakahu skink as "Nationally Critical" under the New Zealand Threat Classification System. [11] It met the criteria for Nationally Critical threat status by occupying a total area of less than 1 hectare. The Te Kakahu skink is considered conservation dependent, in partial decline, and found only in one location. [11]

Chalky Island has never had rats, mice, possums, or deer, and since DOC eradicated stoats with a trapping network in 1999 it has been free from introduced mammalian predators. [12] Te Kakahu skinks are only preyed on by New Zealand falcons (Falco novaezeelandiae). The skinks are active in daytime, sunbathing for long periods, and display little fear of novel species. [3] The single population of skinks remain vulnerable, as an arrival of stoats or an accidental fire would threaten the entire species. [13] [9]

Conservation efforts

In February 2013 DOC staff counted and studied a total of 160 skinks from the Chalky Island site, ageing, sexing, and measuring each individual. [9] [14] A follow-up survey in February–March 2016 confirmed that a relatively abundant population existed to support a harvest of skinks for translocation. [10] [13] A release site was chosen on nearby predator-free Anchor Island, and 99 skinks were transferred in February 2018. Every skink was photographed and its unique scale patterns noted. Anchor Island is home to several endangered birds, such as kākāpō, little spotted kiwi, and mohua, but has no other skink species. [13]

Related Research Articles

<i>Oligosoma</i> Genus of lizards

Oligosoma is a genus of small to medium-sized skinks found only in New Zealand, Norfolk Island and Lord Howe Island. Oligosoma had previously been found to belong to the Eugongylus group of genera in the subfamily Lygosominae; the Australian genus Bassiana appears to be fairly closely related.

The long-toed skink is a species of skink of the family Scincidae, endemic to New Zealand. It was first described by Geoff Patterson in 1997. It is only known from a few sites in the South Island of New Zealand and little is known of its habits. It seems to prefer dry, rocky habitats, usually eroding stream terraces or scree slopes. It is diurnal and heliothermic. Maximum snout-vent length is about 70 mm.

<span class="mw-page-title-main">Scree skink</span> Species of lizard

The scree skink is a species of skink native to several sites throughout the South Island of New Zealand. A member of the family Scincidae, it was described by Geoff Patterson in 1997. It favours rocky habitats, particularly greywacke screes. Threats to scree skinks include predation by introduced mammals, weed encroachment, human interference and severe flood events.

Chalky Island or Te Kākahu-o-Tamatea is an island in the southwest of New Zealand, and is part of Fiordland National Park. It lies at the entrance to Taiari / Chalky Inlet, next to Rakituma / Preservation Inlet, at the southwestern tip of the South Island, 10 kilometres (6 mi) northwest of Puysegur Point, 15 kilometres (9 mi) southeast of West Cape, and 140 kilometres (87 mi) west of Invercargill.

<span class="mw-page-title-main">Whitaker's skink</span> Species of lizard

Whitaker's skink, also known commonly as Whitaker's New Zealand skink, is an endangered species of skink, a lizard in the family Scincidae. The species is found only in New Zealand.

<i>Oligosoma homalonotum</i> Species of lizard

The chevron skink, is a large species of skink endemic to New Zealand, found only on Great and Little Barrier islands in the Hauraki Gulf. A cryptic forest dweller, it can hide underwater, and is under threat from introduced rats.

The small-scaled skink is a species of skink in the family Scincidae. The first specimen was captured in 1971 on Motutaiko Island, Lake Taupō but it is now known to be endemic to the central North Island of New Zealand in small population pockets. The holotype is in the collection of the Museum of New Zealand Te Papa Tongarewa.

<i>Oligosoma notosaurus</i> Species of lizard

The southern skink is a species of skink in the family Scincidae. It is endemic to New Zealand.

Oligosoma taumakae, the Open Bay Island(s) skink, or Taumaka skink, is a species of skink. It was described from the Open Bay Islands, off the west coast of the South Island of New Zealand.

The slight skink is a skink of the family Scincidae, endemic to the far north of the North Island of New Zealand. The precise distribution is unknown; currently it is only known from localities in the Te Paki region of Northland. It closely resembles the copper skink, Oligosoma aeneum, and was considered to be a member of this species until recently when it was described as a new species using morphological, allozyme and DNA methods. O. levidensum is difficult to distinguish morphologically from O. aeneum, which is probably why it had not been recognised until recently. The main distinguishing feature is the slighter overall body form of O. levidensum compared to O. aeneum. The limbs of O. levidensum are reduced compared to O. aeneum and O. hardyi, the other members of the O. aeneum complex.

The Sinbad skink is a rare species of medium-sized skink endemic to New Zealand where it lives in an alpine habitat in Sinbad Gully, in Fiordland National Park.

<span class="mw-page-title-main">Barrier skink</span> Species of lizard

The Barrier skink is a species of medium-sized skink, a lizard in the family Scincidae. The species is endemic to New Zealand, where it lives in the alpine habitat of the Darran and Takitimu Mountains of Fiordland. It is one of only two species of New Zealand skinks that live exclusively in the alpine zone, the other being the "Sinbad skink", Oligosoma pikitanga, a closely related species of similar appearance which is found in the same part of the South Island. The Barrier skink was first collected in the 1960s but was overlooked until rediscovery by a pair of mountain climbers in 2005; the species was scientifically described in 2009.

<span class="mw-page-title-main">Burgan skink</span> Species of lizard

The Burgan skink is a nationally endangered species of skink native to New Zealand. It was described from a specimen found near the Burgan Stream, in the Rock and Pillar Range, Central Otago.

<span class="mw-page-title-main">Cryptic skink</span> Species of lizard

The cryptic skink is a nationally vulnerable species of skink native to New Zealand.

<span class="mw-page-title-main">Nevis skink</span> Species of lizard

The Nevis skink is a nationally vulnerable species of skink native to New Zealand. It is named in honour of the location of its habitat, the Nevis valley.

<span class="mw-page-title-main">New Zealand spotted skink</span> Species of lizard

The spotted skink is a nationally at risk species of skink native to New Zealand. The Spotted skink is currently known to be present in the Hawkes Bay, Wairarapa and Wellington regions as well as in Nelson, Marlborough and Canterbury. It is also present on Somes Island, Mākaro / Ward Island, North Brother Island and Stephens Island. Adult males and adult females of the species significantly differ in the snout-vent length with body sizes reaching 111mm. Females produce around 3 - 4 young.

<span class="mw-page-title-main">Brown skink</span> Species of lizard

The brown skink is a species of skink native to New Zealand.

The Hokitika skink is a poorly-known and critically-endangered species of lizard in the family Scincidae (skinks) found only in the Hokitika area on the West Coast of New Zealand.

<i>Oligosoma salmo</i> Species of lizard

The Chesterfield or Kapitia skink is a species of skink found in New Zealand. Only discovered in 1994 and for years not recognised as a distinct species, it is endemic to a narrow 1 km strip of coastal vegetation on the West Coast of New Zealand, 15 km north of Hokitika. There are fewer than 200 individuals remaining in the wild. Oligosoma salmo is the only New Zealand skink with a prehensile tail, suggesting it was once arboreal and inhabited coastal forest, which was subsequently cleared for dairy farming. Following the partial destruction of its remaining habitat in 2018 by a cyclone, a small captive breeding population was established at Auckland Zoo.

Taiari / Chalky Inlet is one of the southernmost fiords in Fiordland, in the southwestern corner of New Zealand's South Island and part of Fiordland National Park. As with the neighbouring fiords of Tamatea / Dusky Sound to the north and Rakituma / Preservation Inlet to the south, Taiari / Chalky Inlet is a complex fiord with many channels and islands along its roughly 28 km (17 mi) length. Most notably, this includes the sections Moana-whenua-pōuri / Edwardson Sound and Te Korowhakaunu / Kanáris Sound, which split at Divide Head in the middle of Taiari and each extend for roughly 10 km (6.2 mi) inland in a V-shape.

References

  1. Hitchmough, R.; van Winkel, D.; Lettink, M. (2019). "Oligosoma tekakahu". IUCN Red List of Threatened Species . 2019: e.T120190180A120192689. doi: 10.2305/IUCN.UK.2019-2.RLTS.T120190180A120192689.en . Retrieved 20 November 2021.
  2. 1 2 "Te Kakahu skink". Department of Conservation. Retrieved 23 Feb 2018.
  3. 1 2 3 4 Chapple, David G.; Bell, Trent P.; Chapple, Stephanie N. J.; Miller, Kimberly A.; Daugherty, Charles H.; Patterson, Geoff B. (2011). "Phylogeography and taxonomic revision of the New Zealand cryptic skink (Oligosoma inconspicuum; Reptilia: Scincidae) species complex". Zootaxa. 2782: 1–33. doi:10.11646/zootaxa.2782.1.1.
  4. "kakahu". Māori Dictionary. Retrieved 2018-02-22.
  5. 1 2 "Oligosoma tekakahu Chapple, Bell, Chapple, Miller, Daughety & Patterson, 2011". The Reptile Database. www.reptarium.cz. Retrieved 18 July 2015.
  6. 1 2 "Oligosoma tekakahu". The Department of Conservation. The Government of New Zealand. Retrieved 19 July 2015.
  7. Morris, Rod. "New Zealand Frogs & Reptiles". Rob Morris. Rob Morris. Retrieved 20 July 2015.
  8. Jewell, Tony (2011). A photographic guide to reptiles and amphibians of New Zealand (2nd ed.). Auckland: New Holland. p. 89. ISBN   978-1-86966-203-5.
  9. 1 2 3 "Rare lizard thriving on Chalky Island". Department of Conservation. 20 May 2016. Retrieved 23 Feb 2018.
  10. 1 2 Edmonds, Hannah; Loe, Erina. "Te Kakahu skink population estimate". www.doc.govt.nz. Government of New Zealand. Retrieved 22 May 2016.
  11. 1 2 Hitchmough, Rod; Anderson, Peter; Barr, Ben; Monks, Jo; Lettink, Marieke; Reardon, James; Tocher, Mandy; Whitaker, Tony. "Conservation status of New Zealand reptiles, 2012" (PDF). Department of Conservation. The Government of New Zealand. Retrieved 18 July 2015.
  12. "Tieke/Saddleback transfer to Chalky Island". Fiordland Conservation Trust. April 2008. Retrieved 2018-02-23.
  13. 1 2 3 "Big horizons for little skink". Department of Conservation. 15 February 2018. Retrieved 23 Feb 2018.
  14. "Rare lizards on Chalky Island". Behind the Scenes (7): 4. Autumn 2013. Retrieved 19 July 2015.

Further reading