The North Island robin (photo D.Armstrong) was once found all over the North Island, but are now restricted to the central North Island and patchily distributed. They are strongly affected by predation, but have been able to hold on in the presence of predators better than some other species. Robins have been reintroduced to several offshore islands, and are now the first species being reintroduced as part of mainland restoration programs (for review see article in the Bird Issue of Reintroduction News). Reintroductions since 1990 include:
Mokoia Island (135 ha, in Lake Rotorua, North Island). Reintroduction. Translocation from the Mamaku Plateau in 1991 (see Jansen 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. The reintroduction was part of the Mokoia Island restoration programme. The robin population has not been researched, but there now appears to be a large population covering most of the island. Birds have now been harvested for translocation to Moturoa and Tuhua Islands (see below).
Tiritiri Matangi Island (220 ha, Hauraku Gulf east of Auckland). Reintroduction. 44 birds translocated from the Mamauku Plateau, April 1992. A further 14 birds were translocated in June 1993. Tiri was mostly cleared for agriculture, but retained some small bush patches. Most of the cleared portions were planted with native trees from 1983-95. Robins are not recorded from the island, but are presumed to have occurred there historically. The reintroduction was part of the Tiritiri Matangi restoration programme, although it was originally planned to take place when the planted forest was more mature. The population has been closely monitored since its reintroduction, and is being used as a case study of how small populations are regulated. Most robin territories occur in mature remnant patches, amounting to about 15 ha of habitat, and these support about 35 pairs. However, they have recently begun to expand into revegetated areas planted from 1984-1994, and the population was over 40 pairs in the 2002/03 and 2003/04 breeding seasons. The population has been harvested for translocations to Wenderholm (1999) and Great Barrier (2004), and these harvests are being used to experimentally study density dependence and assess the levels at which small island populations can be sustainably harvested. Contact Doug Armstrong.
Mana Island (217 ha, off SW North Island). Reintroduction. 27 robins from Kapiti Island were released in June 1995 and a further 39 in June 1996. The population is now well established. The reintroduction was part of theMana Island Ecological Restoration Programme. Contact Colin Miskelly.
Trounson Kauri Park (managed mainland area, Northland, North Island). Robins released 1998. The population is now extinct. Contact Nigel Miller.
Boundary Stream Mainland Island (ca. 800 ha managed mainland area, Hawkes Bay, near east coast of North Island). Reintroduction/Supplementation. 28 birds from Tarawera Conservation Area (50 km to the west) released 31 March – 8 May 1998. Birds were released within 7 hours of capture. The aims were to restore part of the reserve’s original biodiversity, and use robins to show that there is a “functional indigenous ecosystem” following management. There was at least one solitary male in the reserve before translocation, but this may have been the only robin remaining. Control of rats, cats, mustelids and possums over the previous two years had reduced these predators to low levels, with the aim of improving habitat suitability for robins and other species that may be reintroduced. The robin population had expanded to about 60 birds by the 2000 breeding season, and estimates of nest success (Armstrong et al., N.Z.J.Ecology 2002) suggest predators are being managed effectively. Contact Steve Cranwell.
Wenderholm Regional Park (managed mainland Peninsula north of Auckland). Reintroduction. 21 birds were translocated from Tiritiri Matangi Island, 3-6 March 1999. The founder group consisted of 6 pairs, 3 unpaired males, 1 unpaired female, and 5 juveniles. The size and composition of the founder group was selected to allow us to test whether juvenile survival on Tiri is limited by habitat availability (Dimond 2001). The translocation therefore provides a case study of how island populations (even small ones) can potentially be sustainably harvested for translocation to the mainland. Research to date suggests that the population is hanging on but not growing, and is limited by poor juvenile recruitment. Contact Tim Lovegrove.
Paengaroa Mainland Island (101 ha managed forest block, near Taihape, North Island). Reintroduction. 40 birds were translocated from plantation pines in Waimarino Forest (near Raetihi) from 25-31 March 1999. There was initially a predator control programme in place (using talon cereal baits), but this was stopped in May 2002. Research indicates that reproduction and female survival is strongly affected by rat levels, and that tracking rates need to be maintained at less than about 10% for the population to survive. The population had declined to 4 pairs by September 2004. Contact Doug Armstrong.
Kakepuku Mountain (200 ha mainland forest reserve, south Waikato, North Island). Reintroduction. 30 birds from Pureora forest released in June 1999. Robins would have been there historically, as it is part of their original rang. The local community has been conducting a poisoning campaign since spring 1995 to reduce rats and possums. At least 13 birds survived until November, and fledglings were seen over summer. Contact the Kakepuku Mountain Reserve Management Committee (c/- Jan and Laurie Hoverd, RD3 Te Awamutu Ph:07 8718071).
Moturoa Island (140 ha, Bay of Islands). 19 robins from Mokoia Island (population established in 1991, see above) released 2 June 1999. The island is privately owned. Contact Keith Owen.
Mangaokewa Reserve (200 ha managed mainland site near Te Kuiti). Reintroduction. 30 birds from Waipapa Ecological Area released 18-20 March 2001. Contact Phil Bradfield.
Barnett Reserve (23 ha) andStephenson covenant (4 ha, with addition 5 ha reserve adjacent) (mainland remnants near Waotu, Waikato, North Island). Reintroduction. 30 birds from Waipapa Ecological Area (Pureora State Forest) released in these two mainland remnants 24-31 May 2001. 20 birds (about 11 male, 9 female) released in Barnett Reserve and adjacent covenant, and 10 birds (about 6 male, 4 female) released on Stephenson’s convenant, about 700 m away separated by pasture. Barnett Bush became a reserve in 1992. A group of 6 community members has been doing possum control since 1993, and rat control (50 x 50m bait stations maintained late winter and March) since 2000. There is little sign of mustelids, and cats will be searched for in June 2001. A similar, but more intensive regime is in place at the nearby Stephenson’s covenant, and the whole district has had possum, mustelid and magpie control. MSc student Dave Pattemore (Auckland University) is studying post-release dispersal of these birds in comparison to a similar sized founder group released into continuous bush in the Hunua ranges (see below). Contact Gordon Stephenson about the community led restoration program, Tim Lovegrove re the translocation, and Dave Pattemore re subsequent monitoring.
Hunua Ranges (600 ha mainland island SE of Auckland, part of 17,000 ha continguous forest). Reintroduction. 30 birds from Waipapa Ecological Area (Pureora State Forest) released 24-31 May 2001. These were divided into groups of 10 and 20 birds released 1 km apart in the contiguous forest of the managed kokako block, which is under intensive pest control. Contact Tim Lovegrove, Auckland Regional Council.
Bushy Park Reserve (87 ha mainland forest block near Wanganui). Reintroduction. 28 robins (approximately 21 male, 7 female) from Winstone International Forest (near Raetihi, Central North Island) were released 25-28 August 2001. Reintroduction was done to restore a component of the reserve’s fauna, to test the habitat for potential reintroduction of other more vulnerable birds, and to provide eduation opportunities. Robins bred soon after release and produced at least 14 young in the 2001/02 breeding season, but produced few young in subsequent years and number of females had dropped to 2-3 by August 2004. Decline of reintroduced population associated with high nest predation rate despite attempts to control rats using snap traps. Rat numbers around the reserve may have been especially high due to control of the feral cat population, resulting in high invasion rates. Managed was therefore changed to reduce rat numbers. This included putting the Racumen (Donated by Bayer) at 25m intervals around most of the boundary and also at 100m intervals between traps for a knock down during winter, plus asking surrounding farmers to be slightly less aggressive in their cat extermination. An additional 18 robins (7 male, 11 female) were tranlocated in August 2004. The project is led by the Bushy Park Trust, and is an extension of the nature education program at Bushy Park. Contact Terry O’Connor.
Karori Wildlife Sanctuary (225 ha mainland restoration area surrounded by a mammal-proof fence, central Wellington). Reintroduction. 40 birds from Kapiti Island were released in 2001 (38 in May, 2 in August), and 36 additional birds were released in May 2002. Robins became extinct in the Wellington area about 100 years ago. The reintroduction is part of the restoration program in the sanctuary following eradication of mammals inside the fence (see http://www.sanctuary.org.nz). Robins were caught in clap traps or mist nets, held in cardboard boxes, translocated by helicopter or boat and road, and released within 48 hours of capture. The population was intensively monitored for 4 years and has had high survival and productivity. Despite an increased risk of dispersal following release compared to offshore islands, survival after transfer was good: 75% of robins transferred in 2001 bred in their first year at the Sanctuary compared to 56% of those transferred in 2002. Productivity has also been good with an average of 3.6 fledglings per pair produced in 2001/2 and 2002/3, 3.2 in 2003/4 and 4.2 in 2004/5. An estimated 100 pairs were spread throughout most of the Sanctuary by mid 2005 when monitoring stopped. While robins are found outside the Sanctuary, their survival has been problematic but could improve with predator trapping occurring around much of the Sanctuary since 2006. Contact Raewyn Empson.
Tuhua/Mayor Island (1277ha, Bay of Plenty). Reintroduction. 42 birds from Mokoia Island (see above) were released May 2003. Robins were previously recorded there but had become extinct in the last 30 years. Their extinction was presumably due to predation by Norway rats, which were eradiated in winter 2000 along with kiore, feral pigs and feral cats. Tuhua comproses mainly pohutukawa/hardwood forest with shrublands and wetlands and has considerable potential for ecological restoration. Robins were widespread by 2007. Contact John Heaphy.
Windy Hill Catchment, Great Barrier Island. Reintroduction. 30 robins from Tiritiri Matangi Island translocated April 2004. Robins have been absent from Aotea for about 140 years, and have been released to an area where predators have been controlled to low numbers by the local community. The birds came from the closely-monitored population on Tiritiri Matangi, and pre-feeding of the target birds meant that the birds were captured in less than 24 hours. There were 4 known pairs in the reserve during the first (2004/05) breeding season, plus one additional male. These produced 13 fledglings. Contact Judy Gilbert.
Forest Fragments near Benneydale (Central North Island). Robins were reintroduced to 13 forest fragments on private land near Benneydale from 2005-2007. The reintroductions were part of a Marsden-funded research project testing whether declines of native species from forest fragments were attributable to metapopulation dynamics, and could therefore be remedied by translocation. A total of 135 robins were translocated to fragments ranging from 6-49 ha, all with apparently suitable habitat based on a range of measures. Although many birds dispersed from the release fragments, 36 birds established in these fragments (i.e., present for at least one breeding season), and breeding pairs were established in 11 of the 13 fragments. This led to a total of 80 different adult robins being found in these fragments over the next 3 breeding seasons, and we compared their survival and reproduction to that of 112 robins monitored in 11 naturally-occupied fragments. The overall reproduction rates were almost identical for the two groups of fragments (1.48 independent young per female per year). However, survival was significantly lower in the reintroduction fragments, with annual survival probability estimated to be 0.63 and 0.53 for males and females respectively, in comparison to 0.74 and 0.66 and in the naturally-occupied fragments. We estimated the finite rate of increase,l, to be 1.06 and 0.88 for the two groups of fragments, suggesting that the robin population can maintain itself (l > 1)in the naturally-occupied fragments but not at the reintroduction sites. These results suggest that the initial absences from the reintroduction sites were not due to isolation alone, but also due to subtle differences in habitat quality causing reduced survival in robins. Contact Doug Armstrong.
Kotuku Peninsula, Great Barrier Island Island. On 3-4 April 2005, 27 robins from Tiritiri Matangi Island were translocated to the Kotuku Peninsula (near Port Fitzroy) on Great Barrier Island. Robins are assumed to have been extirpated from Great Barrier by rats and cats (there are no mustelids), and this is the second reintroduction to a predator-control area on Great Barrier (the first was to the Windy Hill catchment in 2004). Rats and cats are controlled over the whole peninsula, with a total area of about 260 ha. This area includes Glenfern Sanctuary. Most of the birds were adults (16 males, 10 females) of known history on Tiritiri Matangi, and one bird was a juvenile. This is the third translocation from the reintroduced robin population on Tiritiri Matangi, and this population is being used to study the effects of harvesting on source populations (Dimond & Armstrong in press, Conservation Biology). Eleven of the translocated robins have been found since the start of the breeding season, and these have formed 5 pairs. These had produced 10 fledglings by midway through the breeding season (early December). See the Glenfern Sanctuary website or contact Tony Bouzaid or for updates on the translocated robins, and contact Doug Armstrong for information on adaptive harvesting of source populations.
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. Fifty-three robins (toutouwai) were initially re-introduced into the Ark in April 2005, from Mokoia Island, near Rotorua. North Island Robins, although not a threatened species, have a contracting range and our re-introduction will increase the prospect of establishing them to a part of their previous range. In the 2005-06 breeding season 5 breeding pairs and 24 chicks were seen. In the 2006-07 breeding season 6 breeding pairs and 25 chicks were observed (2006-07 report). In the 2007-08 breeding season 8 breeding pairs and 24 chicks were observed. In the 2008-09 breeding season 5 breeding pairs and 13 chicks were observed (2008-09 report). After a decline in Robin numbers in 2008-09, which was thought to be in part caused by predation by feral cats, a top-up translocation of 30 birds took place in June 2009, from Mangatutu (Waikato). This supplementary translocation was appropriate as establishing a self-sustaining population in a mainland setting is more likely with additional individuals. For the birds originating in Maungatutu, a higher proportion of birds participated in breeding in the first season after release, compared to those from Mokoia Island. This may be due to island birds “naivety” in relation to predators. Management targeting feral cats has been intensified which appears to have benefited the population further, the ratio of fledgling per breeding pair has increased. In the 2009-10 breeding season 9 breeding pairs and 18 chicks were observed (2009-10 report). In the 2010-11 breeding season 13 breeding pairs, 18 singles and 29 fledglings were observed (2010-11 report). Contact: Maj De Poorter, www.arkinthepark.org.nz
Matiu/Somes Island (25 ha, Wellington Harbour). On 5 April 2006, 21 North Island robins from Kapiti Island were hard released on Matiu/Somes Island. Matiu/Somes Island is a 24.9ha pest free (since rodent eradication in 1989) scientific reserve that lies in Wellington Harbour. The island was cleared for grazing in the late 1800’s and early 1900’s, displacing many of the original plants and animals. Lower Hutt Forest and Bird have led an intensive revegetation programme (since 1981), aiming to re-establish the coastal forest community that would have existed on the island. While there are no historical records of robins on Matiu/Somes it is assumed they would have been present as they were once widespread in the Wellington region. Robins were caught with clap traps from locations at both ends of Kapiti I. to maximise genetic diversity. Plumage colour and tarsus measurements were used to ensure an even mix of male and females were transferred. Existing pairs were caught where possible. Six pairs have nested on Matiu/Somes this season, producing a total of six fledglings by early November 2006. Contact Andrew Morrison.
Tawharanui Open Sanctuary (588-ha predator fenced peninsula 90 km N of Auckland). Reintroduction.On 16 March 2007, 21 North Island robins(Petroica australis longipes), comprising 15 males and 6 females, captured on Tiritiri Matangi Island were released in the Tawharanui Open Sanctuary. On 26 July and 10 August 2007, in two small follow-up transfers to boost the numbers of females in the founding population, four additional female robins were captured in exotic forest and scrublands on private land near Puhoi and transferred to Tawharanui. The 550 ha Tawharanui Open Sanctuary is protected by a pest proof fence and key mammalian predators such as rats, mustelids, cats and possums have been removed. The source robin population on Tiritiri Matangi comprises 35-40 pairs, and it is productive enough to allow robins to be removed at 2-3 yearly intervals to establish populations at new sites. At Puhoi, the robin population is derived from birds, which have dispersed inland from Wenderholm, where 21 robins from Tiritiri Matangi were released in 1999. Since 1999 about 300 young have been produced by the robins in the Wenderholm/Waiwera/Puhoi area, and many of the young have dispersed inland into mostly unmanaged scrublands and exotic plantations. The four females transferred to Tawharanui were harvested from one of these areas. Pre-transfer disease surveillance of 43 robins (24 from Tiritiri and 19 from the Wenderholm/Waiwera/Puhoi area) showed no significant pathogens in these populations, and no significant pathogens were found in any of the transferred birds. The robins were caught with pneumatic clap nets and mist nets. The Tiritiri Matangi robins were held for up to five nights in modified cardboard pet carry boxes and fed waxmoth larvae and mealworms and provided with fresh water. The Puhoi robins were held for only a few hours between capture and release. There was no mortality during the translocations. Survival since release has been very high, and at the start of the 2007-08 breeding season, 23 of the 25 founding birds were still present. Nine breeding pairs became established and all of the pairs bred successfully. During the 2007-08 season they fledged a total of 34 young (3.8 young/pair) from 21 nests. At the start of the 2008 breeding season 22 birds were present, comprising 18/25 of the founding birds and 4/34 locally-bred birds. Although it is assumed that some young birds dispersed out of the Open Sanctuary, none had been found outside the reserve by December 2008. The population included 8 breeding pairs and 6 single males. By mid-December 2008, 27 young had been produced. Contact Tim Lovegrove, Auckland Regional Council.
Ocean Beach Wildlife Preserve (2200-ha managed area on Cape Kidnappers Peninsula, Hawkes Bay, North Island). Reintroduction. 35 birds from nearby Maungataniwha Pine forest were released in June 2007. A 9.5 km predator-proof fence across the peninsula is due to be completed soon, and predator trapping and poison bait stations are being used to reduce densities of rats, cats, mustelids and hedgehogs. The reserve is on private land (Cape Kidnappers Station, Haupouri Station and Ocean Bay Wilderness), so the restoration is being done in conjunction with farming, a golf course and other recreation activities. Disease screening or quarantine procedures were not required, so the birds could be released the same day or the next day after they were caught. ContactTamsin Ward-Smith.
South Island robins (photo D. Armstong) face similar threats to North Island robins. Before 1990 there were successful reintroductions of South Island robins to Motuara and Allports Islands (Marlborough Sounds) and Hawea Islands (Fiordland), and unsuccessful reintroductions to Maud Island (Marlborough Sounds), and Entry Island (Fiordland) and the Conway River area (North Canterbury) (see article in the Bird Issue of Reintroduction News). Reintroductions since 1990 include:
Hinewai Reserve (Banks Peninsula). About 15(?) robins from Motuara Island (Marlborough Sounds) were released in 1994. These birds had been trained to recognise predators, and the idea was to determine whether such birds could be used for reintroduction to the mainland. There was no predator control or other intensive management, and the robins disappeared within 6 months. Contact Ian McLean.
Doubtful & Erin Islands (Lake Te Anau) – South Island robin and South Island saddleback were transloacted to Erin and the Doubtful Islands, a small chain of inshore islands occurring off the south western shore of Middle Fiord of Lake Te Anau, to assess the value of predator-controlled inshore islands for reintroductions of threatened species. Twenty-one adult South Island robins (Petroica australis) sourced from Breaksea Island, Fiordland were released on to Doubtful Island 2 in Mar. 2002, and an additional 18 adult robins from the same site were released onto Erin Island in Sept. 2003. Robins were marked using unique leg-band color combinations. Both robin translocations were believed to consist of equal numbers of males and females based on tarsus length (I. Jamieson, unpubl. data).
Resighting surveys were condensed into three-month intervals beginning in Sept. 2002 (the beginning of the first breeding season) to Mar. 2007 with the exception of June 2003 in which no survey occurred. Surveys during this period were intensive due to a concurrent nest survival study and consisted of visiting breeding pairs approximately every three days during the Sept. – Feb. breeding season throughout the five-year study, and marking chicks with leg-band color combinations as above. Additional one-off post-plague surveys occurred in November 2007 and December 2008, but these were considerably less intensive with survey duration of three to four days in total.
Eight of 21 robins from the Mar. 2002 release were alive at beginning of the first breeding season (Sept. 2002). The population increased to 7 pairs (19 individuals) by the second breeding season, including 7 of the 18 additional robins translocated in Sept. 2003 (the others survived <3 months after release). The population remained relatively stable for the next two years, but increased substantially to 11 pairs (24 birds) by Sept. 2006. The population decreased by half to an estimated 12 birds in the summer following the predator plague of 2006/07. The population declined further to an estimated 8 birds by the last survey in Dec.
Abundance indices obtained from trap-catch data showed a resident kiore (Rattus exulans) population on three of the four main islands while house mice (Mus musculans) were present on all islands. Stoats (Mustela erminea) (along with increased kiore numbers) were caught on all islands during a period of high predator density as a result of beech (Nothofagus sp.) seed mast cycles. Ship rats (R. rattus) were caught on smaller stepping stone islands, which they presumably invaded from the mainland, but were not caught on the four main islands. Post-reintroduction survival analysis from five robin breeding seasons, consisting of four consecutive non-plague years (2002-2006) and one predator plague year (2006/07), gave strong support for lower survival probability of both adults and juveniles during the predator plague year and for changes in adult survival probability between intervals of the plague year. Robin productivity was also negatively affected during the predator plague year with breeding female robins producing 2.725 (S.E. ± 0.388) fledglings in normal years and only 1.183 (S.E. ± 0.330) during the predator plague year. In addition, post-reintroduction survival immediately following translocation was poor, the cause of which is confounded by dispersal to the adjacent mainland, predation, or from stress of translocation.
Projections from a stochastic simulation model suggested that the robin population would increase over a ten-year period if the mean predator plague interval was four years or more, but there was great uncertainty around these projections. Given the unpredictability of beech seed mast cycles in South Island beech forests and poor survival immediately following release, future reintroductions of robins or other species vulnerable to predation to inshore islands are not recommended until further monitoring has been completed. Population viability analysis with parameter sensitivity testing following an additional five years of research would likely be inclusive of another predator-plague cycle, and would provide a stronger template for Wildlife Managers who endeavor to use inshore islands for threatened species translocations. Contact Ian Jamieson University of Otago.
Anchor Island (1140 ha, Dusky Sound, Fiordland). 34 birds from Breaksea island, October 2002, and an additional 32 birds from Breaksea Island, April 2004. Contact Andrew “Max” Smart.
Putauhinu Island (141 ha, off SW Stewart Island). Reintroduction. 15 birds from Pohowaitai Island released March 1999. Part of island restoration following removal of cats and kiore. In Nobember 1999, the robins had dispersed widely and had bred. Contact Peter McClelland.
Ulva Island (269 ha, Paterson Inlet, eastern side of Stewart Island). Reintroduction. 18 birds from Freshwater catchment of Stewart Island (18 km west of Ulva Island) were released September 2000 to February 2001. Part of island restoration following eradication of rats (see entry for South Island saddlebacks). The University of Otago has monitored the robins since release. At the end of the 2003/2004 breeding season, the population comprised 42 adults (including 11 of the founder birds) and 34 juveniles. A look at bird pedigrees on Ulva Island has revealed that 46 of 49 robin offspring are decended from one breeding pair. This is mainly due to the initial breeding success of this pair after translocation. Contact Brent Beaven.
Orokonui – (307 ha predator-fenced mainland site 20 km north of Dunedin). In the first year of a two year translocation proposal, 25 South Island robins Petroica australis were transferred to Dunedin’s Orokonui fenced sanctuary from mature Douglas fir plantations in Silverpeaks (9 km away – 19 birds) and Flagstaff (16 km – 6 birds), over four consecutive days in April 2010. This mainland translocation is of interest because of the relatively short distance from the source populations, which makes ‘homing’ by the robins more likely. The Silverpeaks robin population was monitored prior to the translocation, with most territorial adults banded. The 19 unbanded birds subsequently caught for translocation in April were thought to be post-dispersal juveniles; the 6 additional birds caught at Flagstaff were banded adults located in a small forestry block that was scheduled to be clear-felled. All birds were held overnight in transfer boxes at the release site and appeared to be in good shape when released the following morning. Only 4 birds were resighted in the sanctuary during the first two weeks after release, and a total of 6 of 25 birds (24%) resighted in the sanctuary before start of the breeding period (Sept. 2010), of which two pairs nested. 8 of the 19 birds (42%) sourced from Silverpeaks were resighted back at their capture location, where they subsequently nested. The fate of the remaining 12 of 25 birds (48%) is unknown. For the follow-up translocation, fledglings that are independent (i.e. feeding themselves) but still on their parents’ territory are being translocated and released (with transmitters) to determine whether this younger age-class is less likely to home back to the source population. Contact Ian Jamieson University of Otago.
Pitt Island( Chatham Island Group). Reintroduction. In February 2004, 20 black robins (about 14 male, 6 female) from Rangatira Nature Reserve on South East Island were released in a predator-fenced area on Pitt Island, Chatham Islands group. The fenced area is 40 ha, and is within the 53-ha Ellen Elizabeth Preece Conservation Covenant (EEPCC), which covers 53 ha of mixed broadleaf coastal forest, including kopi, matipo, karamu, hoho and ribbonwood, with areas of grassland. It has been stock fenced for nine years and has regenerated to the type of forest habitat where black robins would have been found historically. Black robin previously occurred only on two small islands, so returning the species to one of the larger islands in the Chatham group is essential in order to provide suitable habitat for the population to expand. Any new site for black robin must be free of cats, and both cats and weak were eradicated from within the fenced area. The 40 ha that is predator-fenced is thought to be sufficient to sustain a new robin population (8 ha of bush on Mangere Island supports a population of over 50 black robins, although the density will probably be lower than on Mangere due to the presence of mice and absence of seabirds). Robins were caught using clap traps, held in a temporary aviary (c. 4m x 4m) on Rangatira until there were up to 10 birds and a period of calm weather for transportation, then transported by boat to Pitt. The birds were transported in cardboard cat boxes (two per box, separated by cardboard divider), then held in pre-release aviaries (6m x 4m and c. 2m high, with 10 birds in each) for 2-4 weeks. Contact Adam Bester.
Karori Wildlife Sanctuary (225 ha mainland restoration area surrounded by a mammal-proof fence), central Wellington, North Island. Reintroduction. 51 tomtits (39 males and 12 females) were translocated to the sanctuary between 2001 and 2004. The reintroduction is part of the restoration program in the sanctuary following eradication of mammals inside the fence (see http://www.sanctuary.org.nz). Most tomtits (36) were caught in the Akatarawas and were hard released the same day or a day after capture. Some (15) were caught on Kapiti Island and spent several days in captivity before transfer and hard release. Breeding in the Sanctuary was confirmed in 2003/4 (2 pairs) and has occurred annually since then (with nesting attempts by 7 females in 2005/6), but recruitment has been problematic despite good productivity (7.0 fledglings per pair in 2003/4, 6.5 in 2004/5 and 6.0 in 2005/6). The expansion of competitive robins in the Sanctuary has probably played a role in this because the tomtits have progressively shifted their territories to the sanctuary perimeter and outside (where few robins survive) and as a consequence has exposed tomtits to a higher predation risk when foraging and nesting outside the Sanctuary. However, predator trapping has begun since 2006 around much of the Sanctuary and this may improve tomtit survival. While the breeding of tomtits following a transfer was a significant breakthrough for the transfer of North Island tomtits, their future in the Sanctuary looks increasingly uncertain. Nevertheless additional birds will be transferred in future if possible to increase the possibility of successfully establishing tomtits in the vicinity of the sanctuary. Contact Raewyn Empson.
Tiritiri Matangi Island (220 ha, Hauraki Gulf east of Auckland). Reintroduction. 32 birds (13 females, 19 males) from pine forests due to be felled in the Hunua Ranges, 60 km SE of Auckland, were released in April 2004. The reintroduction was part of the Tiritiri Matangi restoration programme. The birds were caught by a team of 21 people working 12 mistnets over a 2-day period, but this rapid capture was due to the birds being trained to take mealworms over a 6-month period. A key question for this reintroduction is whether the tomtits would be affected by competition from robins, which were reintroduced in 1992 and now have intense competition for territories. Consequently, robins were removed from several patches for translocation to Great Barrier Island (see below) prior to tomtits being released, and tomtits were released in both “robin-full” and “robin-free” areas to test the effect of competition. Robins colonised the empty areas fairly rapidly and tomtits have been difficult to find in any area. Nevertheless, secretive tomtits continue to be sighted occasionally, and it is too early to assess the success of the reintroduction. One male is definitely no longer on the island, as he has returned to his territory in the Hunuas! Contact Barbara Hughes.
Ocean Beach Wildlife Preserve (2200-ha managed area on Cape Kidnappers Peninsula, Hawkes Bay, North Island). Supplementation. 14 birds (9 males, 5 females) were released in June 2007. There were still some tomtits in the reserve, so the tomtit translocation constitutes re-stocking (or supplementation) rather than a reintroduction. Disease screening or quarantine procedures were not required, so the birds could be released the same day or the next day after they were caught. Contact Tamsin Ward-Smith.
Tuku Nature Reserve. From Rangatira Island