Reintroductions.net

Wader & Shorebird


BlackStilt(kaki, Himantopusnovaezelandiae)

kaki reintroductions

Kaki (photo: P. Cook) are an endangered wading bird found in braided rivers and wetlands in New Zealand. Formerly widespread throughout most of the North and South Islands its distribution is now restricted to the Upper Waitaki Basin, on the eastern side of the South Islands Southern Alps. As at February 2002 there are 47 adult kaki in the wild, of which only 14 – 18 are females. Causes of decline were likely to be predation by introduced mammals (feral cats, ferrets, stoats, Norway rats, hedgehogs, possums) and loss of habitat from invasion of braided rivers by introduced weeds (e.g., crack willow, gorse, broom, lupins), water extraction for irrigation, channelisation from flood protection schemes, flooding or drainage of rivers for hydro-electric power development. Kaki will hybridise with pied stilts, particularly when no female kaki are available for males. The mixed pairs that result have fertile offspring, but survival to adult age is about 50 % of that of pure kaki pairs. All available evidence suggest that kaki are a separate species that have evolved in isolation from pied stilts for around 1 million years. Kaki differ from pied stilts in morphology, plumage, behaviour, mtDNA, voice and in analyses of proteins, and by concordance.

Management of kaki began in 1981, and focussed on protection of wild breeding pairs in situ, by predator control, enhancement of small wetland sites, and artificial incubation of eggs. Captive pairs were established in 1979 at Mt Bruce Wildlife Centre in Wairarapa from eggs taken from the wild. From 1981 to 1987 eight one-year-old sub-adults were released to the wild. A new captive-breeding centre was built in Twizel in 1986, and the birds from Mt Bruce were transferred to it. Twenty-two birds were released between 1987 and 1992 from the Twizel aviaries, as most hatchlings were retained for captive breeding stock, or placed under wild kaki or mixed kaki – hybrid pairs. In 1992, the ratio between chicks held in captivity, and those put back into the wild was changed. More chicks were held and raised in the aviaries ready for release at aged nine months, with the aim of raising up to 30 chicks for release. Nine months was chosen as the release age because the sub-adults would have then been held in captivity over winter, and because this is close to the natural separation time for wild pairs and their offspring. From 1998 experimental releases of juveniles have been tried: to determine whether three-month-old juveniles can be successfully released. Releases have been supplementations rather than re-introductions. All birds released were individually colour banded, and all had transmitters.

Twizel Aviary wetlands 1993-95. Sub-adults released in 1993 (33 birds), 1994 (30) and 1995 (21). Released September-October. 50% of released birds were dead within 50 days in most years. Survival to breeding age (one year after release) was typically 23-43 %. Mortality was mainly attributed to predators or trauma after colliding with obstacles. Movements of birds after release were around the release site, or to the nearby Ohau River, and up to 12 km downstream.

Ruataniwha Wetland, Ohau River delta 1996-97. Seven sub-adults hard-released and 8 soft-released at Ruataniwha Wetland, 35 others released on the Ohau Delta Site B, 1996-1997. Released September-October. Soft-releases from portable aviary, hard-releases direct from transport boxes to wild. Mortality was very high immediately post-release, and 17 survived (35%) survived to breeding age. Predators and to a lesser degree trauma were considered the main cause of death, but evidence for this was limited. Birds released on the Ohau River delta mainly moved to the nearby Tekapo River system, or stayed at the delta.

Cass River area 1998-2000. 21 sub-adults released directly to wild from August-September 1998. 10 (48 %) survived to breeding. The deaths occurred within 10 days of the release following a snowstorm. Supplementary food and iodine (to correct possible goitre) were initiated, and no birds have been confirmed dead since. All birds remained within wetlands in release area. In 1999, 10 juveniles (3 months old) were released in February, and 17 subadults and 3 adults were released in September. All received iodine in their diet, and supplementary food after release. Few birds died after release, and survival over the first 2 months was > 85 % (only two birds found dead). One juvenile moved 32 km south, all other birds remaining in wetlands in the release area. In 2000, 33 juveniles released from January-February. All birds had iodine and supplementary food, and all birds survived the first 2 months. Birds from this release mostly left the release site within five days because birds from previous releases defended feeding territories at the site of the release.

Ahuriri River area 2000-01. 16 sub-adults released in Upper Ahuriri in September 2000. 20 juveniles released mid-Ahuriri River January 2001, 16 sub-adults released lower river, September 2001. Initial survival rates (over first 2 months) close to 100%. One body was recovered from lower river. Cause of death was bacterial infection probably associated with stress of release.

Tasman River area 2001. 9 juveniles released in January and 22 sub-adults in September. Initial survival rates again excellent.

Godley River area 2002. 31 juveniles released in January – February. Three died (bodies eaten by predators), and at least 6 birds have dispersed more than 10 km to nearby habitat.

Future releases will take place annually, with sites selected on the basis of numbers of adults already in the area, and numbers of released birds surviving in the present location. Pulse-releases of large numbers of birds at one site before moving to another is preferred, because it maximises the number of potential mates each kaki can find.

See Maloney & Murray (2000). Contact Richard Maloney.

ShorePlover(Thinornisnovaeseelandieae)

Shore plover were formerly widespread around the New Zealand coastline, but disappeared in the 1800s following introduction of mammalian predators. They also occurred in the Chatham Islands (800 km to the east), and are still found there in on at least two predator-free locations. There are about 130 on Rangatira, or South East Island, and 21 birds were found on a small reef in 1999. There were three translocations of shore plover from Rangatira to predator-free Mangere Island (also in the Chathams) from 1970-73, but these birds mainly flew back to Rangatira after release. The emphasis subsequently shifted to establishing a captive population, to produce captive-reared birds that were thought more likely to stay at their release sites. After several years of trials, eggs taken from the wild now have a hatch rates of 100% and young have fledging rates of 95%. By 1994, the populations at the National Wildlife Centre (Mt Bruce) and Peacock Springs (Christchurch) were producing enough juveniles to attempt re-introduction, resulting in tranlocations to the following sites:

Mana Island – This translocation project aims to establish a fourth self-sustaining population of shore plover by transferring captive-reared juveniles to Mana I. annually for at least 5 years from 2007. So far, 124 juveniles have been released: 38 in 2007, 26 in 2008, 33 in 2009 and 27 in 2010. The birds were all captive-bred at National Wildlife Centre (Mount Bruce) or Isaacs Wildlife Trust (Christchurch). They were usually transferred at 60 – 90 days of age and held in a temporary pre-release aviary on Mana Island for 10 days before release. All birds were colour-banded (with 4 colours) and post-release monitoring was undertaken to assess establishment and breeding success. The first breeding pair established on Mana Island during the season after releases began (2007/08), and produced one chick. Since then the number of breeding pairs and chicks produced has increased each season, to 6 pairs fledging 7 chicks in 2010. As at May 2010 there are 25 resident adults. Contact Rose Collen and Shaun O’Connor.

Motuora Island (ca.50 ha, inner Hauraki Gulf). A total of 75 captive-reared birds (from National Wildlife Centre) were released from 1994-99: 5 in September 1994, 15 in September 1995, 16 in February 1996, 17 in February 1997, 18 from December 1997 to February 1998, and 4 in June 1999. The released birds were a mix of hand-reared and parent-reared birds, and were a mix of adults and juveniles. Of the 53 birds released in the first 4 years, only 14 were still present one month after release, and a total of 8 were present in September 1997. The first breeding was recorded in 1998/99 when the two pairs present laid eggs, but neither produced fledglings. The one pair present in 1999/00 successfully fledged one young, which dispersed to a neighbouring island. Of the birds that disappeared after release, and whose fate could be determined (due to transmitters), 53% dispersed to other locations (neighbouring islands or adjacent coast) and 13% were taken by ruru, or morepork, a native owl. Observations of shore plover and ruru after release suggest that ruru may have been scaring shore plover from the island as well as successfully preying on them. The recovery group therefore decided to attempt a release to a site without ruru.

Island X (The 2nd release site is privately owned and the owners do not wish to attract publicity, hence is name is excluded). 15 hand-reared juveniles from the National Wildlife Centre were released in August 1998, and 10 juveniles (mostly parent-reared) were released in July 1999. Post-release mortality and dispersal has been much lower than on Motuora, and 14 of the 25 released birds were still present in March 2000. Breeding occurred in the second year, with 4 fledglings produced by 5 pairs.

UPDATE: Over 100 captive bred juvenile shore plover were released onto Island X from 1998 until releases finished in 2006. The shore plover programme on this island has been very successful so far and the population is considered to be well established and self-sustaining.

See Aikman (1999) and O’Connor (2000). Contact Shaun O’Connor.

Snipe(Coenocoryphaaucklandica)

Putauhinu Island (141 ha, off SW Stewart Island). On 16 April 2005, 30 Snares Island Snipe (C. a. buegili) from North East Island (Snares Islands) were released on Putauhinu. Patauhinu formerly had a population of the Stewart Island Snipe (C. a. iridalei), but this population is assumed to have been extirpated by the introduced cats and/or kiore on the island. The cats died out naturally in the 1960s and kiore were eradicated in 1996. The Stewart Island Snipe became extinct after ship rats invaded Big South Cape Island in the early 1960s (an attempt to translocate snipe from Big South Cape in August 1964 was unsuccessful). The translocation of Snares Island Snipe therefore represents a taxonomic substitution in terms of restoring the Putauhinu ecosystem, and also increases the distribution of Snares Island Snipe which is range restricted. The snipe were captured with handnets, and held in two aviaries until translocation. Contact Colin Miskelly.

Send message via your Messenger App
Scroll to Top