|Black stilt, Ashley River mouth.|
The black stilt or kakī (Māori), Himantopus novaezelandiae, is a large wader in the avocet and stilt family Recurvirostridae. The species is endemic to New Zealand. Adults are 40 cm long. They have very long red legs, a long thin black bill and black plumage. Juveniles have a white breast, neck and head, with a black patch around the eyes. Unfortunately, the black stilt is the world's rarest and least populous Charadriiform.
Ecology and conservation
Despite 20 years of intensive protection, this species remains the rarest wading bird in the world. Intensive management of black stilt began in 1981, when the population had declined to just 23 adult birds. The current wild population is estimated at 85 adult birds (February 2010). There is a captive population of some 13 adults. Annual release in the wild of captive-bred birds, and predator control have probably prevented black stilt from becoming extinct in the wild. During the breeding season, it is restricted to the Mackenzie Basin in the South Island. The majority of the black stilts will also overwinter in the Mackenzie Basin, unlike other waders in the region that migrate to warmer climates for winter.
They breed at 2–3 years of age. They are one of the world's most endangered birds. Drainage and hydroelectric development has in the past disturbed their braided river bed habitat. Predation from mammalian invasive species, most notably mustelids such as stoats, presently poses a serious threat to the survival of the species. The third major threat to this species is hybridization with the local and more numerous pied stilt H. himantopus.
Effect of hydroelectric power development
Because the black stilt nests on the braided rivers beds of the South Island, it is threatened by changes in river flows as a result of new hydro dams and changes in flow regimes for existing dams.
The Upper Waitaki Power Development posed a threat to the habitat of the black silt. A program was set up to lessen this threat. The black stilt population on the river beds varies with the river level. Changes in the level of Lake Benmore, which caused corresponding changes in the deltas of the incoming rivers, affected the local population of black stilts.
- BirdLife International (2013). "Himantopus novaezelandiae". IUCN Red List of Threatened Species. Version 2013.2. International Union for Conservation of Nature. Retrieved 26 November 2013.
- Rod Morris and Alison Ballance (2008), "Rare Wildlife of New Zealand", Random House, page 113
- Maloney, R., and Murray, D. 2002. Kaki (black stilt) recovery plan 2001-2011, NZ Department of Conservation: Wellington.
- Reed &, C.E.M.; D.P. Murray (February 1993). Black Stilt Recovery Plan (Himantopus novaezealandiae). Threatened Species Recovery Plan Series NO.4. Wellington, New Zealand: Department of Conservation (New Zealand). ISBN 0-478-01459-7. Retrieved 2008-09-09.
- Ministry for the Environment (May 1998). Flow Guidelines for Instream Values. ME271 Volume B. Wellington, New Zealand: Ministry for the Environment (New Zealand). Retrieved 2008-09-09.
- Sanders, Mark (1999). "Effect of changes in water level on numbers of black stilts (Himantopus novaezelandiae) using deltas of Lake Benmore". New Zealand Journal of Zoology 26 (2).