Kapiti Island(1965 ha, off west coast of sothern North Island). 30 birds from Little Barrier Island were released in August 1983, a further 30 in August 1984, a further 12 in August 1990, a further 48 birds in August 1991, and a further 47 in August 1992. See Castro et al. (1994a, b). The population has remained stable or slowly declined, possibly needing this continual supplementation to maintain it. It was hoped that the eradication of Norway rats in 1996 would result in population growth, but it is not clear that this has happened. In August and November 2002, a further 15 birds from Mokoia Island were released (see below). The Kapiti Island population may (like Kapiti) have tenuous viability even with management (no analysis has been attempted and the data may be insufficient), but there is an ongoing commitment to manage hihi on Kapiti, resulting in the relocation of the Mokoia hihi to Kapiti.
Mokoia Island (135 ha, in Lake Rotorua, North Island). 40 birds (20 male, 20 female) were translocated from Little Barrier Island, September 1994. Mokoia was cleared for agriculture but the forest has now been naturally regenerating for 40-50 years. Norway rats and goats were eradicated in 1989. Hihi are presumed to have inhabitated Mokoia historically, and the reintroduction was part of the Mokoia Island restoration programme. This is the only inland population of hihi. Research initially focused on post-release survival and effect of post-release management (Armstrong et al., 1999) and on testing whether the population was limited by availability of fruit and nectar. Our research suggests that reproduction is limited by food supply, but survival of birds is limited by other factors. An on-off food supplementation experiment (Armstrong & Perrott 2000) showed that there was no time in the first year when condition or survival of birds was limited by availability of carbohydrate food (click here for a photo of the setup used for the supplementation experiment). Nevertheless, the population has a high (50-60%) annual mortality rate for both adults and juveniles, both in the year of the experiment and in subsequent years when food was supplied continuously. Most dead hihi recovered have extensiveAspergillusinfections, and we suspect a high susceptibility to Aspergillosis in this population is contraining the survival rate regardless of food supply. This is to countered by a high breeding rate, but only if there is supplementary feeding during the breeding season and management of nest boxes to prevent mite buildup. Hihi produced very few young in 1998/99, when supplementary food was removed altogether. Population viability analysis suggested that the population might persist with supplementary feeding and nest box management during the breeding season, but would be extinct in less than 5 years if this management were discontinued. Due to this necessary commitment of ongoing management, the remaining 15 birds were relocated to Kapiti Island in August and November 2002. Contact Doug Armstrongor Isabel Castro.
Tiritiri Matangi Island (220 ha, Hauraki Gulf east of Auckland). 37 birds were translocated from Little Barrier Island in September 1995, and another 14 birds were translocated in August 1996. Tiri had been mostly cleared for agriculture, but retained some small bush patches. Most of the cleared portions were planted with native trees from 1983-95, and kiore were eradicated. Hihi are not recorded from the island, but are presumed to have occurred there historically. The reintroduction was part of the Tiritiri Matangi restoration programme, and the revegetation programme was partially designed with hihi in mind. Hihi are provided with nest boxes, and these are checked for mite buildup during the breeding season. There are also sugar-water feeders available throughout the year. Unlike Mokoia, there was extensive mortality of females immediately after release in both 1995 and 1996. The second translocation was mostly females, and was intended to balance the sex ratio (12 males, 4 females in the 1995/96 breeding season). However, while post-release mortality was high, the mortality rate has otherwise been much lower than on Mokoia. Also unlike Mokoia, an on-off supplementation experiment showed that condition and survival or birds is limited by food supply in at least some years. The effect of supplementary food in the breeding season has not been tested. In intensive management regime is currently in place for this population, and the population appears to have good prospects of survival if that regime is maintained. Contact John Ewen or Doug Armstrong.
Karori Wildlife Sanctuary (225 ha mainland restoration area surrounded by a mammal-proof fence, central Wellington, North Island). Reintroduction. Following disease screening and quarantine, a total of 60 mainly juvenile hihi (31 females and 29 males) from Tiritiri Matangi Island were released at the Karori Wildlife Sanctuary in February and May 2005. 4 captive-bred hihi were also translocated from Mt Bruce between February and May 2005 and an additional 6 juveniles and 2 adults between January and April 2006. This was the first reintroduction of hihi to a predator-fenced mainland area. Birds were offered Wombaroo nectivore mix and sugar water as supplementary foods. Initial survival was good compared to survival following transfer to Kapiti, Tiritiri and Mokoia Islands, despite the increased risk of dispersal, with 90% birds still alive 5-6 weeks after release. By September more soft released birds were alive than hard released birds but the reverse was the case by February 2006. The breeding season exceeded all expectations, with nesting beginning several weeks earlier than elsewhere and 89 chicks fledged successfully, an average of 5.2 fledglings per female. Contact Raewyn Empson orMatu Booth.
Ark in the Park (2350 ha of managed mainland centred around Cascade Park, Waitakere Ranges Regional Park, plus approx 600 ha of pest control on private property). The Ark in the Park is a community driven open sanctuary Kauri in the Waitakere Ranges Regional Park, close to Auckland City. It is a partnership between Auckland Council and Forest and Bird, supported by Te Kawerau a Maki. The project started in January 2003 and the aim is to allow the restoration of a functioning native ecosystem through intensive pest control and unlike many other mainland sanctuaries there is no predator proof fence. Instead, ongoing pest control (rodents, mustelids, possums and feral cats) by volunteers and staff keeps predator numbers low enough to allow survival and breeding of re-introduced as well as original native birds and other biodiversity. 59 hihi were reintroduced into the Ark in the Park area in April and June 2007, from Tiritiri Matangi Island. The reintroduction was experimental as it is the first transfer to an area with low numbers of predators. Following a recommendation from the Hihi Recovery Group meeting in 2008, an additional 51 hihi (50/50 male /female) were translocated from Tiritiri Matangi Island to Ark in the Park. Bird feeders and nesting boxes have been located in the central area of the Cascades to assist their establishment. Post release monitoring has been carried out and breeding-season monitoring is carried out. In the 2008-09 breeding season 19 adults and 25 fledglings were observed. Two males from the 2007 release successfully nested, as well as several individuals from the 2008 release. An unbanded adult female was observed feeding chicks in December 2008 – leading to the conclusion that she was an “Ark-born” female from the season before. Hihi did not use the nest boxes that had been provided for them, but instead all nests that were observed were in natural cavities in kauri. In the 2009-10 breeding season 5 adult males and one adult female were observed. In addition, one pair of hihi can be considered as confirmed to the SW outside the Ark area and unconfirmed reports also suggest hihi presence to the NE outside the 2009-2010 Ark managed area. No nesting was observed, but in early April 2010 an unbanded bird was sighted in the Ark core area which is thought to be a juvenile from this season (due to plumage). This could indicate that at least some undetected breeding had taken place. The low numbers are likely due to a combination of: stochasticity associated with low numbers; higher rat numbers than usual due to rich food supply, high feral cat numbers in the 2008-09 season and dispersal out of the core area. In May 2010 the Hihi Recovery Group (led by DOC) restated the desirability for attempting the re-introduction of hihi into the Ark in the Park, but also decided against further top-up translocations at this stage, and to revisit this when more is known about hihi natural dispersal. The reintroduction of hihi to the Ark in the Park was always known to have an experimental element to it – the Ark being the only mainland site with hihi where a predator controlled site is surrounded by non-controlled contiguous habitat that may act to “lure” hihi away. As such the Ark is a significant testing site for the overall national efforts under the guidance of the Hihi Recovery Group. Contact: Maj De Poorter, www.arkinthepark.org.nz
Contact Kate Richardson for research on factors affecting post-release survival and dispersal, Doug Armstrong for information on the effects of harvesting from Tiritiri Matangi Island, and John Sumich for updates on hihi at Ark in the Park.