South Island kōkako

The South Island kōkako (Callaeas cinereus) is a possibly extinct forest bird endemic to the South Island of New Zealand. Unlike its close relative the North Island kōkako it has largely orange wattles, with only a small patch of blue at the base, and was also known as the orange-wattled crow (though it was not a corvid). The last accepted sighting in 2007 was the first considered genuine since 1967, although there have been several other unauthenticated reports.[1]

South Island kōkako
North Island kōkako (front) and South Island kōkako (rear)

Critically endangered, possibly extinct  (IUCN 3.1)
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Passeriformes
Family: Callaeidae
Genus: Callaeas
Species:
C. cinerea
Binomial name
Callaeas cinerea
(Gmelin, 1788)
  Estimated maximum distribution
  Estimated distribution around time of European settlement
Synonyms

C. cinerea cinerea

Taxonomy

The kōkako was first described by German naturalist Johann Friedrich Gmelin in 1788 as Glaucopis cinerea, from the Latin cinereus ("grey"). For some time the North Island and South Island birds were considered subspecies of Callaeas cinerea, but since 2001 North Island birds have been officially recognised as C. wilsoni, and genetic evidence confirms their difference.[2] Although the genus Callaeas is masculine, the species epithet cinerea is not masculinised to match, though some authors have argued it should be.[2]

Description
South Island Kōkako (Callaeas cinerea) specimen from the Auckland Museum collection

Like the North Island kōkako, this was a slate-grey bird with long legs and a small black mask; Reischek considered its plumage slightly lighter than the North Island species. Its wattles were distinctly orange in colour with a dark blue base; young birds had much lighter wattles.[3] It seems to have spent more time on the ground than the North Island species, but been a better flier.[4] Kōkako have distinctive organ- and flute-like duetting calls. Early explorer Charlie Douglas described the South Island kōkako call: "Their notes are very few, but the sweetest and most mellow toned I ever heard a bird produce."[5] Based on extant records, South Island kōkako eggs were larger than their North Island counterparts.[6]

Distribution

At the time of European settlement, South Island kōkako were found on the West Coast from northwest Nelson to Fiordland, as well as Stewart Island, Banks Peninsula, and the Catlins. Subfossil bones suggest they were formerly found throughout the South Island, but forest burning by Polynesians eliminated them from dry eastern lowland forest.[4] Introduced mammalian predators and forest clearance by settlers reduced their numbers further: by 1900 the bird was uncommon in the South Island and Stewart Island, and had almost disappeared by 1960.[4] Its vulnerability compared to the North Island species was perhaps due to its foraging and nesting close to the ground.[7]

Conservation status

The South Island kōkako was formally declared extinct by the Department of Conservation in 2007, as it had been 40 years since the last authenticated sighting at Mt Aspiring in 1967.[8] In November 2013, however, the Ornithological Society of New Zealand accepted as genuine a reported sighting by two people near Reefton in 2007, and changed the bird's New Zealand Threat Classification status from "extinct" to "data deficient". Eleven other sightings from 1990 to 2008 were considered to be only "possible" or "probable".[9]

A supposed kōkako feather was found in 1995,[10] but examination by scientists at the National Museum showed it to be from a blackbird. Unconfirmed sightings of South Island kōkako and reports of calls have continued,[11][12][13][14] but no authenticated recent remains, feathers, droppings, video, or photographs exist. The IUCN Red List status of the species is, as of 2016, Critically Endangered (Possibly Extinct).[15] The most recent unconfirmed sighting was in November 2018, in the Heaphy Track in Kahurangi National Park.[16]

References
  1. Evans, Kate (July 2016). "In Search of the Gray Ghost". New Zealand Geographic. Archived from the original on 2016-07-02. Retrieved 2016-08-07.
  2. Gill, B. J.; Bell, B. D.; Chambers, G. K.; Medway, D. G.; Palma, R. L.; Scofield, R. P.; Tennyson, A. J. D.; Worthy, T. H. (2010). Checklist of the Birds of New Zealand. Wellington: Te Papa Press. p. 281. ISBN 978-1-877385-59-9.
  3. Reischek, A. (1885). "Notes on the Habits of some New Zealand Birds". Transactions and Proceedings of the Royal Society of New Zealand. 18: 105–107. Retrieved 8 April 2016.
  4. 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.
  5. Ward, Paul Stanley (Feb 2015). "Chasing Grey Ghosts". Up Country. Retrieved 7 April 2016.
  6. Gill, B.J. (1993). "NATAL DOWN AND EGG SIZE OF THE KOKAKO CALLAEAS CINEREA (AVES: CALLAEIDAE)". Records of the Auckland Institute and Museum. 30: 87–91. ISSN 0067-0464.
  7. Szabo, M. J. (2013). Miskelly, C. M. (ed.). "South Island kokako". New Zealand Birds Online. Retrieved 8 April 2016.
  8. Atkinson, Kent (16 January 2007). "DoC declares South Island kokako 'extinct'". The New Zealand Herald. Retrieved 13 October 2011.
  9. Morton, Jamie (27 November 2013). "'Extinct' South Island kokako could still be alive". New Zealand Herald. Retrieved 4 February 2014.
  10. "Research uncovers possibility of South Island kokako" (PDF). New Zealand Journal of Forestry. 41 (1): 7–8. 1996. Retrieved 7 April 2016.
  11. "Fresh signs of long-lost kokako in Fiordland". New Zealand Herald. NZPA. 3 April 2006. ISSN 1170-0777. Retrieved 7 April 2016.
  12. Angela Gregory and NZPA (17 January 2007). "Expert refuses to give up 20-year search for kokako". The New Zealand Herald. Retrieved 13 October 2011.
  13. Redmond, Adele (5 April 2016). "Once-extinct Kokako sighting near Nelson 'the best in many years'". Stuff. Retrieved 7 April 2016.
  14. Moore, Bill (8 July 2014). "Mixed reaction to kokako 'sighting'". Stuff. Retrieved 7 April 2014.
  15. Birdlife International (2016). "Callaeas cinereus". IUCN Red List of Threatened Species. 2016. Retrieved 17 Jan 2017.
  16. Newman, Tim (10 November 2018). "Sightings spark hope in the search for New Zealand's most wanted bird". Stuff. Retrieved 10 November 2018.
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