Habitat and Ecology
Molecular Biology and Genetics
Statistics of barcoding coverage: Himantopus novaezelandiae
Public Records: 0
Specimens with Barcodes: 5
Species With Barcodes: 1
IUCN Red List Assessment
Red List Category
Red List Criteria
- 2012Critically Endangered
Date Listed: 01/16/2008
Lead Region: Foreign (Region 10)
Where Listed: Entire
Population location: Entire
Listing status: E
For most current information and documents related to the conservation status and management of Himantopus novaezelandiae , see its USFWS Species Profile
Hybridisation with H. leucocephalus, which was allowed to continue under former management strategies, posed a threat because the crash in the Black Stilt population made it difficult for them to form conspecific pairs and a biased sex ratio resulted in single males mating with H. leucocephalus females or hybrids (Pierce 1984, R. Maloney in litt. 1999, Steeves et al. 2010), although hybridisation has been bidirectional (Steeves et al. 2010). Extensive bidirectional hybridisation appears to have been taking place since at least 1960 (Steeves et al. 2010). The sex ratio is now even and the frequency of hybridisation has decreased (R. Maloney in litt. 2008, Steeves et al. 2010). Adjustment of the sex ratio, low reproductive success in hybrid females and high mortality are the likely reasons for a lack of widespread introgression between the two species (Steeves et al. 2010). Adult mortality in the wild remains very high (Keedwell 2005). Despite the genetic bottleneck experienced by H. novaezelandiae, there is so far no evidence of inbreeding depression in the wild (Steeves et al. 2010). However, a negative relationship has been shown between inbreeding and fitness in the captive population; in light of this care should be taken to minimise the relatedness of pairs forming in captivity (Hagen et al. 2011).
Recent advances in release methods appear to have enhanced the initial survival of released birds from 20-45% to 80-100%, but require further testing (Chambers and MacAvoy 1999). Active management involves double and triple clutching of parents by removing eggs to encourage re-laying. The removed eggs are reared in captivity. Playback calls are broadcast to juvenile birds during captive-rearing to equip them with the behavioural and auditory recognition skills necessary for survival (Galbraith et al. 2007). A study was recently published on the influence of release age, size of release group and size of the wild population at release sites on the post-release movements of captive-reared Black Stilts, with implications for the future management of the programme (van Heezik et al. 2009). Predator exclusion fencing was first installed at the site near Lake Tekapo in the late 1970s (Anon. 2009). Trapping for predators around all wild nests has been on-going since 1997 (R. Maloney in litt. 1999), and research is underway to determine the nature of the threat from each predator species (D. P. Murray per A. Grant in litt. 1999). Hybrids, now numbering fewer than 20 within the Black Stilt's range, are controlled (R. Maloney in litt. 2008). Water-levels are manipulated in managed wetlands to attract birds to feed, and possibly breed, in areas where predators are controlled (Dowding and Murphy in press). Habitat restoration is on-going, and involves the removal of exotic weeds from riverbeds (Heather and Robertson 1997). The introduction of a second population on a suitable predator-free island is desirable and has undergone a feasibility study (Murray and Sanders 2000, R. Maloney in litt. 2008), but it is unlikely that a suitable release site will be found. The species's recovery plan reportedly aims to increase the population to at least 250 breeding birds by 2011 (Anon. 2009). Conservation Actions Proposed
Continue to monitor population trends. Monitor rates of habitat loss and degradation throughout the species's range. Maintain and improve productivity of the captive population, and ensure pairs forming in captivity are sufficiently unrelated to prevent potential inbreeding depression (Hagen et al. 2011). Establish a self-sustaining population on a predator-free island. Encourage public interest and support (Reed and Murray 1993). Seek to maintain predator-free habitat for breeding within its current range. Continue efforts to prevent hybridisation with H. himantopus, and maintain parity in the adult sex ratio in order to avoid conditions under which introgression with H. himantopus could occur (Steeves et al. 2010).
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).
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