Number 38 September 2000 RARE BITS THE NEWSLETTER ABOUT THREATENED SPECIES WORK

This newsletter is produced FEATURE ARTICLE primarily as a vehicle for information exchange between departmental staff control in the Eglinton Valley involved in threatened species recovery and from Peter Dilks ecological restoration Various stoat control research projects have 1999 was a beech mast year, and a stoat programmes. In recognition been carried out in the Eglinton Valley since population irruption occurred during the of wider interest, however, “Rare Bits” is also provided 1990. Over the past 2 years continuous, following summer in response to the to non-departmental groups low intensity stoat control has been huge increase in rodent numbers. on request. The newsletter’s undertaken using Mk VI Fenn traps. Trap Bird monitoring informal style may sites are spaced at 200 m intervals along a Kaka occasionally lead to 45 km line that runs the length of the valley, misunderstandings for some The beech forest seeded heavily in 1999 with a short line across the valley at the of those readers. Views and in 2000, and kaka breeding was expressed by the authors are top and bottom. Each of the 198 sites widespread. Kaka in the Eglinton Valley not necessarily those of the consists of a wooden tunnel with two Fenn generally start nesting in January when Department of traps. Traps are baited with a hen’s egg or/ are most abundant. Overall we Conservation. and a piece of meat. The trapline takes 1+ monitored 25 kaka nests by 13 different days to service and is usually checked females. Twenty nests successfully monthly. This stoat control research is a fledged 55 young. One female double joint project between Science & Research brooded in 1999 rearing 5 then 2 chicks. and Area Office staff. In 1999 two nests failed at the chick stage FEATURE ARTICLE The effectiveness of this stoat control is Stoat control in the owing to predation by either a stoat or Eglinton Valley 1 evaluated by monitoring breeding and possum but both females survived. This CONSERVANCY NEWS survival of colour-banded mohua and season we lost three nests, one with eggs Northland 3 radio-tagged female kaka. and two with chicks, and 2 females were Auckland 4 Stoat trapping killed probably by a stoat. All five nests Bay of Plenty 4 Stoats caught in the valley since August that have been lost were the most distant East Coast/Hawke’s Bay 5 Tongariro/Taupo 6 1998 are shown below. from the trapline. Wanganui 7 160 Mohua Wellington 8 140 Intensive monitoring of 27 breeding pairs Nelson/Marlborough 10 (38 nests) was carried out this past West Coast 11 120 summer. No mohua fledged before Otago 11 100 Southland 12 juvenile stoats were being caught in the 80 OTHER BITS Fenn traps. Results: Aerial possum control at 60 • 25 nests fledged chicks successfully Whirinaki and impacts on 40 • 3 failed (female OK) kereru and kaka 14 20 • 10 failed (female killed) Shore plover reintroduction 15 New Sebaea ovata population 15 0 - 6 rat predation Takahe programme Aug Oct Dec Feb May Aug Oct Dec Feb Apr - 1 probably falcon 1999/2000 update 16 - 3 unknown (2 tree unclimable, 1 females and nests in an untrapped area. possible stoat/rat?) This summer we may not have lost any So 66% of nests fledged, 37% of females nests to stoats, but the huge increase in were lost but a stoat may have killed rat numbers and the associated rat only one of these. predation is a major concern. An unusual feature of this breeding The Te Anau area has had two mild season was the high level of predation winters and there is some suggestion that by ship rats - unrecorded in the Eglinton this results in high rat populations in in previous 6 years of intensive nest beech forest. High rat numbers have monitoring. been recorded elsewhere in South Island Effectiveness of stoat control beech forests this past summer – in areas It appears that stoat control carried out where no stoat control has been at this low intensity provides sufficient undertaken. protection to markedly reduce stoat If a permanently higher rat population predation on breeding mohua and kaka. were a result of continual stoat trapping, Kaka breeding success is up with the there would be serious consequences for best recorded anywhere. In similar beech many bird species. It could be suggested forests Ron Moorhouse has recorded 9 that stoat trapping be initiated only of 10 kaka nests failed at Rotoroa with following beech mast years, but for kaka, no stoat control and 3 of 5 females were at least, stoat control would need to occur killed this season alone. Landcare during the previous summer when beech Research also recorded only 10% of nests flowering initiates widespread breeding. fledging young during their 9-year study. If some kaka breeding occurs in all years However, within the Mainland Island at then continual stoat control is preferable, Rotoiti 8 of 10 nests have been successful. because we knew of no successful kaka Over the past two seasons in the Eglinton nests in the Eglinton Valley before we we have recorded 80% of nests initiated stoat control. successfully fledging young. We have To keep the stoat population at a low recorded no mortality of 17 fledglings level with a low density of traps probably that have been radio tagged over the past requires continual trapping. Further work 2 years (35% mortality has been recorded is needed here on rat population for Rotoiti fledglings). dynamics in beech forests to determine Stoat control also appears to be effective whether lack of predators means a larger for mohua breeding because during the irruption in mast years or if climate is 1990 stoat irruption we lost 60% of the major influence.

RARE BITS No. 38. September 2000 2 CONSERVANCY NEWS NORTHLAND records; 25 records had to be missed out. from Nicky Syddall, Lisa Forester, A positive spin-off, however, has been and Andrea Booth the addition of a further 55 new Christella dentata planting at threatened plant sites to the database, Lake Ngatu including range extensions for a few Just over 12 months ago, the Kaitaia Area species. Some of these records are purely took over ‘guardianship’ of the very rare serendipitous as result of surveyors fern Christella dentata. Approximately finding themselves at the wrong site, e.g. 160 plants had been cultivated from the a new major site for Mazus novaezelandiae last remaining few found on private in Warawara Forest in the next catchment property in Awanui. A keen local botanist over from the original record! Being able had taken the initiative for this action, to get more accurate population and he then handed the plants to DoC information for many of these older to manage. records is another good outcome of the Approximately 120 of these plants went survey. back into the property from which they Work continues on finding the identity came, and then finally on 5 July most of of the odd cunonia-like tree discovered the remaining plants were planted near the Hokianga, using genetic and around Lake Ngatu. Permission was morphological techniques. Eleven plants needed from Te Rarawa and Ngai Takoto have been found so far, and one old to move the ferns from one rohe to fallen inflorescence. Another visit will be another. Permissions were granted, the made soon to look for flowers. programme manager was invited to Northland mudfish survey speak to a group of people from Ngai Survey work continues for this Takoto who are the kaitiaki of Lake Northland-endemic mudfish species, Ngatu, and then in the afternoon the which was discovered in 1998. Mike planting went ahead with great success. McGlynn has been trapping for mudfish The planting was a community effort at all likely-looking sites in the Kerikeri including many of the people and area and has so far come up with some children from the marae, Conservation very exciting results. This species was Corps students, DoC staff and volunteers previously known from only two sites, from Bushlands Trust. which makes it one of the most Threatened plant surveys threatened fish species in the country. The Northland threatened plant re-survey In the past few weeks, Mike has of older (pre-1980) records is almost discovered Northern mudfish at four new finished. The data is now being loaded sites, which has significantly extended onto the database and mapped. Around its range. The new sites range from 10- 200 sites were field surveyed, with only 240 m a.s.l. and are a combination of 47% of the plants being successfully conservation and private land. None of relocated. These poor returns could be the new sites have had mudfish present attributed to several causes, with the in high numbers, and some sites are main one being land clearing, especially threatened by development, farming around the Kaitaia area where positive practices, and mosquito fish. Mike still ...Some records are purely returns were low. Not all sites could be has several sites to survey, so we may serendipitous as a result of end up with even more sites for Northern surveyors finding themselves surveyed owing to lack of site mudfish. at the wrong site... information especially for the earlier

RARE BITS No. 38. September 2000 3 CONSERVANCY NEWS AUCKLAND of the new arrivals will start in spring from Bec Stanley and continue through summer. Rare plant bits Our mawhai Sicyos australis at Otuataua It may be the most common leafy Stonefields is proving to be a little tricky mistletoe in the country, but in Auckland to manage. After re-locating one plant, Ileostylus micranthus remains at just six it was promptly eaten by wayward cows. sites, only one of which is on protected Another then sprung up and was sprayed land. Our kaiaua population is on a deliberately by an adjacent landowner. roadside, and it’s running out of hosts, We are waiting and hoping another will as they gradually die of both old age appear. Seed collected off the plants were and exposure to the elements. Coprosma taken to the botanic gardens, but they propinqua and saltmarsh ribbonwood did not germinate. (Plagianthus divaricatus) are the main BAY OF PLENTY hosts here. This population borders a from Paul Cashmore and Keith DoC reserve so we were able to plant Owen, eco-sourced hosts (and other species) Dactylanthus immediately behind our mistletoes. We Staff have just finished checking seed set hope that when the planted shrubs get at sites around the conservancy with bigger, they will provide more habitat similar levels to last year being recorded for the mistletoe, and it will spread onto at most sites. Six more cages have been the new hosts in the DoC reserve. Forty added to the Paeroa Range sites. Eighty- eager volunteers planted around 900 five standard and 5 custom cages were shrubs. added at the Oropi site with the help of The first Tupeia antarctica has been volunteers. Staff in Tauranga have found on Fanal Island in the Mokohinau checked out a couple of reports from Islands by Phil Todd from the Great the Otanewainuku-Oropi area but have Barrier Area Office. Tupeia was once not been able to confirm Dactylanthus know on the mainland in Auckland, but at either site. there haven’t been any plants found for over 50 years so it was presumed extinct Rorippa divaricata in the conservancy. Phil found 2 plants This year’s annual survey at Lake on a maire (Nestegis apetala). Okataina has substantially increased the The coastal cress (nau) species Lepidium known distribution and number of flexicaule has been re-introduced into Rorippa plants at this site. The known the wild in Auckland on Rangitoto Island. population has increased from 6 plants In a joint Auckland Regional Botanic (1998), 26 plants (1999), to 109 plants in Gardens and DoC project, 150 small 2000. The increase appears to be due to plants and also some seed and seedlings, further searching this year revealing more were planted on Rangitoto Island. plants (thanks in part to help from a keen Lepidium flexicaule is extinct in the local amateur botanist who regularly North Island, but was once found at fishes on the lake) plus an increase in many coastal sites in Auckland including plants at most existing sites. This work ...one plant was promptly North Head, Takapuna, Onehunga, reinforces the important point that eaten by wayward cows. Okataina is currently the largest known Another was sprayed Rangitoto, Waitakere and Te Henga (the population of Rorippa on mainland New deliberately by an adjacent most recent record of this species in landowner... Auckland from the 1930s). Monitoring Zealand.

RARE BITS No. 38. September 2000 4 Mokoia Island, Lake Rotorua season of pest control and outcome Staff have just finished planting monitoring. Performance-based contractors, Dactylanthus taylorii seed on Mokoia who trap possums to less than a 5% Island. They planted an estimated residual trap catch, cover 50,000 ha of 70,000+ seeds at six sites around the the northern Te Urewera National Park. island mainly near mahoe and kohuhu Interspersed amongst this are ‘core areas’ host trees in a 2-day operation. This where more intensive pest management planting is a Dactylanthus Recovery takes place. At present there are four core Group priority and has been several areas: Otamatuna, Onepu, Mangaone years in the planning following and Waikokopu. consultation and approval from the At Otamatuna, stoat control has resulted Mokoia Island Trust Board last year. This in 70% of monitored chicks is only the second predator free island surviving to over 1000 g (the ‘stoat-proof’ in the country where Dactylanthus has weight) during the past 4 years of been introduced. Staff will monitor sites management. This compares to a 5% annually for any sign of germination or survival rate in other unmanaged North flowering, but it is likely to be many years Island sites. before we know if this planting has been A breakthrough in stoat control successful. With plenty of young host developed by NTUERP may have been trees and no possums or rats Mokoia has achieved using freeze-dried rats as a lure long been considered an ideal habitat to trap stoats. When placed under a for establishment of Dactylanthus. plastic cover these rats have remained Staff spent another day on the island effective in trapping stoats for up to 6 checking on the survival of two other weeks under field conditions. threatened plant species introduced to Two hundred and eighty tunnels each the island late last year as part of the containing two Fenn traps were set along island’s ongoing restoration. Mistletoe 42 km of lines on ridges, spurs and (Tupeia antarctica and Ileostylus streams covering 1500 ha. The tunnels micranthus) seed was planted on a were alternately lured with a freeze-dried range of host trees around the island but rat and plastic egg (which, along with so far does not appear to have hen eggs, are currently the best long- established. However the endangered lasting stoat lure) in one tunnel, followed native cress Rorippa divaricata has faired by a plastic egg in the next. Over a 3- better with 50% of the original plantings month period 57 stoats were caught. Fifty having established and set seed, although (88%) were caught in tunnels containing half of these have died off over winter. the freeze-dried rats, which is The plentiful seed gives us hope that new significantly higher than the number plants will establish in the spring and caught using plastic eggs alone (p<0.001, viable populations result. Fischer’s exact test). Kokako numbers continue to increase EAST COAST/HAWKE’S BAY at a rapid rate, despite the 1999/2000 from Rhys Burns and Steve Cranwell season being a relatively poor breeding Northern Te Urewera Ecosystem season. Monitored nests at Otamatuna Restoration Programme had a 42% success rate. Kokako at Onepu (NTUERP) and Mangaone both achieved a 50% The NTUERP continues to show success rate. Waikokopu, in its first year impressive results following another of intensive pest control, yielded a 20%

RARE BITS No. 38. September 2000 5 CONSERVANCY NEWS nesting success. This compares to nesting A trial to test the effectiveness of a rodent- success rates ranging from 66-88% at based formula of Cholicalciferol (Feracol) Otamatuna over the past few seasons. in maintaining rat activity below a 5% At Otamatuna, only 8 pairs of kokako tracking tunnel index appears promising. were known in 1995, but a census in After 1 month of the baits having been May/June this year revealed that 44 pairs available activity levels have been are now present (up from 28 pairs in reduced to zero in the treatment area, June 1999). Onepu pair numbers have and remain at 40% in the non-treatment increased from 5 pairs in 1996 to 14 pairs site. The trial will conclude at the end of this autumn, while Mangaone now also August. contains 14 pairs, an increase of 4 pairs since intensive pest control began two TONGARIRO/TAUPO seasons ago. from Cam Speedy and Nick Singers Two of these areas (Otamatuna and Mistletoe Mangaone) used ‘Pindone’ poison to An excellent report entitled “Impact of control rats, whereas Onepu and possum browse on Tupeia antarctica at Waikokopu used the novel non-poison Ketetahi (Tongariro National Park)” has technique of trapping rats in corflute been received from volunteer Phil Eades. tunnels baited with peanut butter. This information will provide an Surprisingly, the trapping outperformed excellent basis to monitor ongoing the poisoning method, reducing rat possum impacts if and when future tracking indices much faster and keeping control occurs. It seems this species is a them at very low levels for longer than particularly sensitive measure of possum the poisoning method. impact. Foliar browse methodology Boundary Stream Mainland showed that 62% of 79 plants had no Island leaves at all 5 years after an October 1995 The 3 Operation Nest Egg kiwi released aerial possum control operation. into Boundary Stream from March 2000 Kiwi to May 2000 have responded positively Four sub-adult kiwi have recently been to their new surroundings. Progressive released into the Karioi Rahui on the weight gains having been made among southern slopes of Mount Ruapehu. all three with the first of the released These birds were removed as eggs from birds now at 1300 g and the latter two nearby Waimarino Pine Forest and raised at 975 g. The birds’ movements have as part of Operation Nest Egg. Together been largely confined to the reserve, with integrated pest control over an although one foray was made some 2 increasing area at the Rahui it is hoped km from the reserve onto the other side these birds will seed a kiwi population of the range. recovery. Meanwhile in Tongariro Forest Monitoring of adult male kiwi within the 21 Operation Nest Egg birds have now eastern Kawekas has resumed. The been released since 1997. Despite at least number of transmitted birds has been three deaths (ferret, pig & misadventure) increased from 5 to 8. With incubation and five transmitter failures, the having started amongst some of these remaining 13 birds are doing well and kiwis, it is hoped a larger number of all remain within various parts of juveniles will be released into Boundary Tongariro Forest. Stream over the coming season.

RARE BITS No. 38. September 2000 6 WANGANUI Three sites are in native vegetation, one from Rosemary Miller and Graeme is a pond on a horse stud covered in La Cock willows, and the fifth in drains in pasture Yes, it’s a short-jawed! in sand country. Her largest fish find was Stratford Area Office short-jawed kokopu 185 mm. spawning site hunters have finally been Threatened plant workshop rewarded with success! Last year the team Jim Campbell put together an excellent tracked down the first ever record of a workshop for the Whanganui Area staff. koaro spawning site which fuelled the The regular contractors (for animal enthusiasm to crack the elusive short- control, weeds etc.) were keen to learn jawed kokopu. A new recruit to the team about plants, so they were included as (Jazz, the dog) may have been the secret! well. All round it was a great 2 days with Eggs extracted from under boulders everybody contributing heaps and about 20 cm above the water level were learning a lot. Chat to Jim if you want to positively identified through genetic try something similar. analysis as being short-jawed kokopu. At the workshop Myles Gembitsky opted Eggs found on gravel amongst sticks to look at the ground for Alepis flavida (also located above the water level just leaves, which proved more successful above a pool where banded kokopu are than searching the trees. So we now have known to hang out) turned out, not evidence of mistletoes in two more trees surprisingly, to be banded kokopu. at the Raetihi motor camp. Jim Clarkson Brown mudfish habitat came across from Stratford to discuss restoration work Dactylanthus work and caging. Stratford Area staff have enhanced the Since this workshop Myles has found two habitat at a mudfish site with the addition populations of Brachyglottis turneri on of 400-plus plants. Once established, the the Whanganui River. The second planting will triple the amount of population is opposite Tangahoe available habitat at this site. Other Landing and has extended the known planting filled in gaps in the secondary distribution of the species in the region. growth in the area fenced last year. If This was one of the species that staff habitat enhancement proves successful were asked to look for. further trials of translocating fry will New and used staff follow. Assessing the success of last In Palmerston North Area Office Don year’s fry transfer programme is on hold, Ravine has been given the task of pending the arrival of some 3-mm Gee- programme manager for plants as well minnow traps ordered from America and as his previous threatened animal presently held up in customs. portfolio. Viv Nicholls, who has probably Mudfish in the Manawatu done contracts for most plant people in A student from Massey University has the lower North Island, has been been highly successful in increasing the appointed as a ranger. Her main focus known mudfish sites in the Manawatu. will be threatened plants and PNA. Previous to her survey, mudfish had been Welcome Viv, but please give the recorded from 1 site, but now 41 fish helpdesk a break. have been tracked down in 5 locations.

RARE BITS No. 38. September 2000 7 CONSERVANCY NEWS WELLINGTON well. Blackberry has proved too strong from Philippa Crisp, John Sawyer, a competitor for some individuals. Amanda Baird, and Christine Reed At Chudleigh CA, Barkers koromiko Conservancy Office (1995), CI ribbonwood (Plagianthus A draft mistletoe atlas and guide has been chathamicus, 1995 & 1999), CI kakaha produced for all 8 species found in (1999), rautini (1998) and toetoe Wellington Conservancy (Loranthaceous (Cortaderia turbaria, 1997 and 1999) and Korthalsella spp.). A bibliography have generally done very well. Stock of plant checklists has also been caused some minor losses. The 1997- published for the Chatham Islands. This planted Chatham Island toetoe have refers to sources of plant information survived well. stored on the Chatham Island Flora At Wharekauri CA Chatham Island Database used to map the distribution speargrass (Aciphylla traversii) has been of all native and exotic plants. introduced. Planting has occurred in five A draft coastal dune vegetation seasons since 1994. Speargrass can do protection and restoration strategy has well in fern/pouteretere (Cyathodes also been produced that describes the robusta) habitat as witnessed by growth conservancy status, distribution, and of 1999 planted material. 1998 plantings conservation needs of dune vegetation were blitzed by pigs. New seedlings have (especially pingao, spinifex, sand established from the earliest of the tussock, sand coprosma and sand planted speargrass. daphne). At Tangepu CA results range from excellent to poor. There were stock Wairarapa Area problems prior to the fence repair. Species A new plant species has been confirmed doing relatively well are toetoe, coastal from the northern Wairarapa. First speargrass (Aciphylla dieffenbachii), shore recorded by Andrew Townsend during spurge (Euphorbia glauca) and pingao PNAP survey work Melicytus aff. blondin (Desmoschoenus spiralis). Pingao and is known from only three sites in the area. shore spurge have struggled because of Material collected during a recent visit dune profile changes. Unsuccessful by DoC plant scientist Peter de Lange plantings include sowthistle (Embergeria has been checked by Brian Molloy, grandifolia) and Cook’s scurvy grass. and we have been notified that it is a Chatham Island forget-me-not (Myosotidium new taxon. hortensia) were destroyed by cattle and Chatham Area (CA) sheep, although some individuals have Staff have assessed threatened plants grown well and produced seedlings. planted since 1993 at several protected CI kowhai (Sophora chathamica) areas. Eighteen species (of several planted in 1994 at Smiths Private Reserve provenances) have been planted. Plants has done well only on steep lagoon were raised from seed collected locally banks. and grown at Motukarara Nursery and Little spotted kiwi then at the Chatham DoC nursery. For the first time in and In Nikau Bush CA Barkers koromiko possibly the first time in the world, a (Hebe barkeri - planted in 1995), ...possibly the first time in the species has been re-introduced to the Chatham Island (CI) kakaha (Astelia world, a species has been re- mainland following its demise there. chathamica) and rautini (Brachyglottis introduced to the mainland Twenty little spotted kiwi were following its demise there... huntii, 1998) have survived and grown

RARE BITS No. 38. September 2000 8 transferred from Kapiti Island to Karori The objectives of the workshop were: Sanctuary, Wellington, between 4 and 6 • To inform species managers about the July. Six pairs, 2 adult males, 2 adult principles, prevention and management females and 4 juveniles were all alive of wildlife disease. and well when released within 30 hours • To demonstrate procedures for of capture. examination, sampling and necropsy The Karori Sanctuary is a former water to determine causes of illness/death. catchment area in Wellington City, only We were especially privileged to have 3 km from Parliament Buildings. This Dr John and Mrs Margaret Cooper from 240-ha area of mainly native bush was the University of Kent as specially invited ringed with a predator-proof fence in guest presenters. John is a leading 1999, and all mammals were removed wildlife veterinarian, having worked in during an intensive trapping campaign Central and Eastern Africa, United Arab and aerial application of Brodifacoum Emerates, Mauritius and Madagascar. poison in 1999 (though mice have since Margaret has a legal background reinvaded). The creation of this large specialising in animal welfare and law. predator-free area in the heart of They teach graduate veterinary courses Wellington allowed the reintroduction of throughout the UK, run courses for a species that had disappeared from its veterinarians in Africa, and are advisors natural range. to Jersey and London Zoos. John and Brown teal Margaret were joined by staff with a Brown teal, bred through the Ducks wealth of wildlife experience within Unlimited network were transferred to IVABS, and by Dr Richard Jakob-Hoff Kapiti and Mana Islands on 14 August. from Auckland Zoo, and Jerry Pauli who Twenty-three brown teal have been provides veterinary advice to the National quarantined for 30 days at Hamilton Zoo Wildlife Centre. and have been screened for a wide range The course covered: defining disease, the of waterfowl disease organisms. Ten value of health monitoring and sampling, female and 5 male birds will be released case studies from black stilts, takahe, on Kapiti Island at three sites: Okupe Auckland Zoo and the National Wildlife Lagoon, Rangatira and Wharekohu. On Centre, zoonoses (disease transmissible Mana Island, 5 female and 3 male birds between humans and animals), will be released in the newly created parasitology, disease recognition in the Waikoko wetland. field, physical examination and first aid, obtaining samples for diagnosis, National Wildlife Health in establishing baseline health parameters, Conservation Training Course genetic sampling, practical disease The course was organised by Wellington management, risk assessment in Conservancy and the staff of the Institute translocations and captive management of Veterinary, Animal, Biomedical programmes, oil spills, avian anatomy, Sciences (IVABS) at Massey University euthanasia and post-mortem, and exotic during 11-13 July. Fifty-nine participants disease. registered, comprising mainly DoC area Staff feedback has been extremely staff from almost every conservancy. positive with suggestions for potential Private individuals and organisations follow-up events. Veterinary Continuing interested in wildlife conservation also Education at Massey is keen on an attended. international wildlife disease conference.

RARE BITS No. 38. September 2000 9 CONSERVANCY NEWS Margaret and John have expressed swamp sedge (Carex tenuiculmis) were interest in returning to conduct three 1- both found on conservation land along day workshops on forensic pathology forested stream sides and on swampy and animal law, wildlife rehabilitation, high terraces under manuka respectively. and reptiles. There is also potential for This makes a total of seven known stronger training links between UK populations of red swamp sedge in the universities and ourselves. conservancy, all confined to the upper Buller catchment. The Howard NELSON/MARLBOROUGH population is the largest of the four from Shannel Courtney and Jan known on protected land. None of the Clayton-Greene Howard flats is fenced from stock from Threatened plants the adjoining farm, and cattle are having Remonitoring of sand spikerush a major impact on vegetation structure, (Eleocharis neozelandica) on Farewell processes, and quality. Spit in May has revealed that the A July monitoring trip to several islands population, though still small, continues in the Marlborough Sounds has to expand after the huge knock-back confirmed the maintenance of very from Cyclone Dreena a few years back. healthy populations of Cook’s scurvy Very encouraging is the successful grass and muttonbird groundsel (Senecio establishment of a new colony, which sterquilinus), both being maintained by we transplanted further along the spit prolific sea bird numbers and activity. last December. Populations of the coastal Kirkianella, Most of the Biodiversity Section, gossamer grass (Anemanthele), coastal Technical Support crew spent 2 days on spurge (Euphorbia glauca) and the a team-building exercise up the Cobb coastal speargrass Aciphylla squarrosa Valley helping Golden Bay Area staff also appeared to be either stable or cage red and orange mistletoes on increasing, while fierce lancewood has mountain beech trunks. A total of 13 become locally extinct on one island - cages were artfully constructed to protect presumably from storm damage. numerous mistletoes on their ‘last twigs’ South Marlborough plants from the ravages of possums and deer. Thirty Australopyrum calcis subsp. calcis A general survey into the headwater plants, the Category A limestone basin of the Howard River in the upper wheatgrass, were planted this week in Buller catchment has revealed a number South Marlborough in the hope of of threatened plant species. The low- establishing an insurance population. lying topography, numerous wet sites, The subspecies currently grows at only and the frosty nature of the area gave us one site around a limestone outcrop on a good indication that there could be farmland and could easily be wiped out some interesting finds here. Both leafless by fire or landslides. Three more mahoe (Melicytus flexuosus) and erect populations of Urtica linearifolia have hook-sedge (Uncinia strictissima) were been found, two as a result of RM found on river banks and terraces on consent inspections. Staff have given adjoining private land. This is the second- talks to the Marlborough District Council known locality for erect hook-sedge in ...13 cages were artfully and to an NGO meeting about threatened constructed to protect the northern South Island. Small plant conservation and have received a numerous mistletoes on populations of the diminutive native lot of encouragement from council staff their ‘last twigs’... foxglove (Ourisia modesta) and red and the public.

RARE BITS No. 38. September 2000 10 WEST COAST of a translocation (probably accidental) from Jo Crofton, Josh Kemp, Paul of the species away from its natural range van Klink, and Don Neale in the Kahurangi National Park area, so Okarito brown kiwi it was decided that the site does not This season 20 pairs are being monitored require active conservation management. for Operation Nest Egg and 10 pairs in However, because few such the ‘study area’. Eleven eggs have been translocations are documented, a full laid so far, and 3 of these were collected report of the survey was written and is for incubation in August. Two Operation on DOCNet DME file WSCCO-17185. Nest Egg chicks are paired with wild OTAGO birds and 4 Operation Nest Egg chicks from John Barkla are also paired up with each other, no Alexandra grasshoppers eggs have been laid by these birds, yet. Mike Tubbs at Alexandra has been Two wild chicks from 1998 are both still analysing data from last summer’s grid alive, 1 is still with its parents. These are search monitoring of Alexandra the first wild chicks of known age in the grasshoppers. Looking at two sites he forest since this project began. In October counted them both on different days. The the 13 chicks on Motuara Island will be results confirm that numbers of these reintroduced to the forest. animals can vary wildly over short periods of time. Mike has also confirmed A kea nest was discovered when hunting that temperature effects are crucial in the lowland forest of the Paringa Valley. determining whether the grasshoppers It was in the base of a live silver beech are out at all. The November 1999 floods (c. 1.5 m diameter). The burrow was well in Alexandra inundated the key site at worn and guano was evident on the Earncleugh Tailings Historic Reserve for forest floor out from the nest entrance. up to 4 days. Searches so far have The nest was approximately 1.2 m deep not been successful in relocating and a torch was required to inspect the grasshoppers at this site. occupants. The three downy chicks Mice and beech seed present were huddled together and the Dawn Palmer at Queenstown reports that tail of an adult was seen behind the the quarterly mouse tracking lines and chicks. From the size of the adult’s bill it beech seed fall in the Caples and Dart is thought to be a female. The birds acted Valleys have been completed. Both completely defenceless during the visit indices are up with mouse tracking rates and none made any noises during the averaging 43% in the Caples Valley and disturbance. 73% in the Dart. Beech seed fall in the Powelliphanta annectens Dart is tapering off after reaching 3968 A snail shell found on the outskirts of seed per square metre in March and 2336 Hokitika was handed in to us by a local in May this year. This is the third year farmer/teacher in June and identified as that large numbers of beech seeds have Powelliphanta annectens. Follow-up been produced in the Dart. surveys found 2 live snails in the vicinity, Stoat trapping and a proposed burn of the area was Bruce McKinlay and Barry Lawrence put off indefinitely by the farmer who ...the farmer was over the have been tidying up the results from moon about his discovery of was ‘over the moon’ about his discovery. an investigation into the microsite factors Powelliphanta annectens... The population is undoubtedly the result

RARE BITS No. 38. September 2000 11 CONSERVANCY NEWS that might affect trap success when Island. This is an increase of almost 150% trapping for stoats in beech forest. The since 1995. Protection occurred at five results, which featured on a recent TV3 key breeding sites on Stewart Island and news story, indicate that to increase the targeted the control of rats and cats by probability of trapping stoats, tunnels using ‘Baitek’ (1080 cat bait) and should be placed in close cover. Other ‘Rentokil’ (bromodiolone rat bait) in bait factors such as the close presence of a stations. tree or a track did not improve trap Owing to the success of this success. management, a greater number of birds Coprosma obconica may now be breeding outside the This vulnerable shrub was until recently treatment areas where they are known from just two sites in Otago, both vulnerable to predators. A distribution discovered within the last 3 years. In the survey is planned for this coming last month a further two sites have been breeding season to determine where found: Nugget Point and lower Taieri birds are breeding on Stewart Island. This Gorge. At three of the four sites it is survey may also reveal breeding areas among dry coastal shrubland and low that could be incorporated into the forest in association with another protection programme. threatened plant, Olearia fragrantissima. Following the breeding season on Stewart Island, all birds descend to the Mazus novaezeelandiae subsp. coast and form winter flocks, which stay impolitus together until August. Some birds cross Several historical sites for this vulnerable Foveaux Strait to winter in coastal herb are known from Central Otago and Southland, particularly in Awarua Bay. are a priority for survey. John Barkla and This is the only post-breeding flock of Amanda Smale recently carried out a the species known from outside Stewart search of one such site at Luggate Creek, Island and can comprise up to c.30% of a tributary of the Clutha River. They first the total population. The count familiarised themselves with the species undertaken at Awarua Bay in early April and its habitat at a site near the Clutha this year as part of the annual census outlet which still has a good population. found 51 birds. This is the highest Despite a couple of hours of intensive number recorded at the bay since 1972. searching no plants were found. Stewart Island stoats SOUTHLAND After the discovery of prints that looked from Brent Beaven, Pete McClelland, suspiciously ‘stoatish’, and a history of Wynston Cooper, Murray Willans, potential sightings, traps were set in eight and Brian Rance locations to determine the status of stoats Southern NZ dotterel on Stewart Island. Over 28 000 trap nights The southern subspecies of the NZ failed to capture any stoats. This suggests dotterel breeds above bushline on that they are either absent from the Stewart Island (Rakiura). The total island, or only present in extremely low population of the subspecies had been numbers. reduced to c.65 in 1994 but rose to c.150 Survey trapping will be conducted for 1 in 1999 and 185 this season following month every 2 years to monitor the cat poisoning operations undertaken situation. around key breeding sites on Stewart

RARE BITS No. 38. September 2000 12 Snares Islands weeds proposed covenant contains at least Chrissy Wickes has undertaken a several hundred adult plants of a healthy feasibility study for the eradication of mixed-age population. weeds from the Snares Islands. Te Kakahu Campbell island rat eradication Staff have just returned from a trip to Te Following the allocation of funds for this Kakahu and, once again, no sign of stoats project advanced planning is underway. was detected. Blue Mountains mohua The trap line on the adjacent mainland The two predator guild monitoring trap (a distance of 1100 m away) was checked lines were operated in the Blue again but not cleared and approximately Mountains again last summer. A total of 80% of the 108 traps set was still available 12 stoats were caught in 35,280 corrected to catch stoats. Only 5 stoats and a few trapnights (CTN). Over the five summers rats were in the traps. This trap line was that the lines have been operated the last cleared during February 2000. This number of stoats caught tallied 13, 6, 12, is particularly encouraging, because even 5, and 12 respectively. after a stoat plague year it looks as Because of the extremely heavy beech though two trap checks per year will be seedfall of the preceding autumn and the sufficient on the mainland. predicted consequent mouse and stoat If no further sign of stoats has been plague, a further three trap lines were detected on either the Passage Islands installed in and about an area with a or Te Kakahu by February 2001 we particularly high Mohua population. expect to be able to say with some These lines were operated over confidence that all stoats have been November and December only and eradicated. By then the project will have accounted for 11 stoats in 13,556.5 CTN. been through consecutive stoat plague Given that the mouse index trapping years on the mainland and two stoat undertaken in November 1999 resulted in breeding seasons on Te Kakahu, and it a 33-fold increase in numbers caught will have been 20 months since the last compared with any of the preceding 5 stoat sign was recorded. years, the lack of a significant increase in Trained stoat dogs are also taken on each the number of stoats caught was trip to Te Kakahu and have yet to find somewhat unexpected. Therefore one any sign there. tends to the conclusion that for reasons Stoat Island immigration study unknown in the Blue Mountains there is This work has been funded by the stoat a low population of stoats and/or that a research group and is aimed at stoat irruption does not necessarily follow determining how often stoats swim to a major beech mast year and a subsequent islands of varying distances (150-1150 m) significant increase in mouse numbers. (It’s from a source population. something of a case of the more we find Twenty five islands have been identified out the less we really know!) in Doubtful, Breaksea and Dusky Sounds Coprosma pedicellata for this work. Standard trap tunnels and While on an inspection of Waituna Scenic density of tunnels will be placed on each Reserve and a nearby proposed QEII island and checked twice annually for 5 covenant Coprosma pedicellata was years. Islands without rodents and of a found. The scenic reserve contained a size insufficient to hold a resident stoat small to moderate population, while the population have been chosen.

RARE BITS No. 38. September 2000 13 OTHER BITS AERIAL POSSUM CONTROL AT caught by a cat while feeding a couple WHIRINAKI AND IMPACTS ON of metres above the ground. KERERU AND KAKA Fifty-three kaka have been captured and from Ralph Powlesland, Science & survived at least a fortnight after being Research Unit radio-tagged. Of these, 3 (5.7%) have This project is funded by the Animal died, giving a mean life expectancy of Health Board, Science & Research Unit, 20.5 years. All 3 kaka that died were and Rangitaiki Area Office of DoC. Its females killed by unknown predators. objectives include determining the costs The carrot-1080 aerial possum poisoning (mortality as a result of the poison operation occurred in May 2000. The pre- operation) and benefits (reduced feed baits were distributed at 5 kg/ha mortality and increased breeding success by the contractor, Epro Ltd of Taupo, on after the poison operation as a result of 1 May. The poison bait (10 kg/ha, 0.08% poisoning introduced mammalian 1080, 2435 ha treatment area) was predators and competitors) of an aerial distributed on 17/18 May. Monitoring of 1080 possum poisoning operation to bait distribution (10 lines each of 1 km kereru and kaka in Whirinaki Forest Park. long, with the requirement that there be This requires the radio-tagging and at least 1 bait in each 50 m segment) monitoring of kaka and kereru in a indicated a 99.5% coverage. None of 17 treatment area (Otupaka Ecological Area) kaka (10 male, 7 female) in the treatment and in a non-treatment area (Oriuwaka area, and 20 (9 male, 11 female) in the Ecological Area). non-treatment area died during the The project began in October 1998. To fortnight following the poison drop. date, 63 kereru have been captured and Similarly, none of 15 kereru in the survived at least a fortnight after being treatment area died after the poison drop, radio-tagged. Of these, 28 (44.4%) have but 1 of 11 (9.1%) died in the non- died, giving a mean life expectancy of treatment area. Five dead birds were just 0.9 years! Although the cause of found in the treatment area: 3 , 1 death or species of predator involved is chaffinch and 1 hedge sparrow. Muscle not always obvious, the following are samples have been taken from each and the assumed causes: 1 died on a nest, 2 will be tested for 1080 in due course. collided with vehicles, 5 killed by cats, 6 Possum monitoring in the treatment and killed by mustelids, 5 killed by falcon/ non-treatment study areas (six lines of harrier, 2 killed by poachers, and 8 killed 20 traps in each) during February 2000 by unknown predators. Most of the resulted in 31.4 and 32.9 captures/100 deaths were in autumn (43%) and winter trap nights respectively. Monitoring was (29%), when the kereru were feeding repeated in the treatment area following mainly on miro fruit. A diet of miro fruit the poison operation (12-16 June 2000) makes the kereru thirsty. The birds drink resulting in 4.4 captures/100 trap nights, at puddles and streams in the forest just below the objective of 5% RTC. where they are vulnerable to predation Likewise, the impact of the poison by cats and stoats. A further 25% of the operation on rodent and mustelid dead birds were found in spring 1999 populations was monitored using when little fruit was available and many tracking tunnels (10 lines of 10 tunnels kereru were feeding on foliage in the in each study area), pre-operation understorey. One of the birds had been monitoring in April 2000 and post- operation in June, 3 weeks after the drop.

RARE BITS No. 38. September 2000 14 The tracking index for rats went from 56 In contrast to Motuora, post-release to 76% in the non-treatment area, but 43 survival and residency has been high at to 5% in the treatment area. All rat prints the new site. There have been no were in one line of tunnels near the recorded deaths of released birds on the boundary of the drop zone. The mouse island. Eighteen months after the first index declined in the non-treatment area release, residency was 53%. In October (30 to 14%), but increased in the 1999 territorial aggression levels rose treatment area (23 to 30%). The mustelid noticeably, particularly amongst the first index declined from 2 to 0% in the non- release birds. Three birds dispersed to treatment area, and 6 to 0% in the the mainland between September 1999 treatment area between the two and February 2000 following this increase monitoring sessions. in social pressure. However 5 pairs In conclusion, the results to date indicate subsequently formed over the 1999/00 that the aerial 1080 possum poisoning season and successfully bred, fledging 4 operation has not had a detrimental chicks. These 4 juveniles are still resident, impact on the tagged kereru and kaka. and the total population currently stands A large proportion of possums and rats at 28 birds (63% residency). were killed. This latter outcome is In the meantime, the Motuora expected to result in greater food programme claimed success – the first resources (particularly flower buds, breeding of ‘wild’ shore plover on flowers and fruit) and reduced predation ‘mainland’ New Zealand this century with of eggs and chicks of kereru and kaka one staunch pair fledging young in the in the treatment area next summer. 1998/99 season. Unfortunately, of the 2 Monitoring will continue to determine chicks produced 1 was predated and the whether such benefits do eventuate for other died from a leg injury. The same the radio-tagged birds. pair pulled it off again in the 1999/00 season, fledging 1 chick, which was seen SHORE PLOVER recently on a neighbouring island with REINTRODUCTION a male released in early 1998. The from Shaun O’Connor successful pair is still resident on Last season saw a milestone for the Motuora; they have obviously learnt to reintroduction of shore plover to survive in the presence of morepork. ‘mainland’ New Zealand. A shift in release Over the last month shore plover at the sites has brought speedy progress. second release site have began The reintroduction programme shifted squabbling and drawing boundary lines site in mid 1998 following the wind up on their patches for the coming season. of large-scale releases on Motuora Island Watch this space! after further clear evidence of morepork predating and scaring released birds from NEW SEBAEA OVATA this island. The new site, a privately owned POPULATION island free of significant introduced from Jim Campbell predators and morepork, has subsequently For several years the Whanganui Area seen three annual releases of shore Office has had the dubious honour of ...the Motuora programme claimed success with the first plover since 1998. (The island is not managing this critically endangered breeding of wild shore plover being named to respect the owner’s gentian which, despite our best efforts, on mainland New Zealand... wishes.) seems destined to slide towards extinction. Sebaea ovata occupies a very small area

RARE BITS No. 38. September 2000 15 OTHER BITS in the coastal Whitiau Scientific Reserve. pairs increased from 47 to 49 (4.2% This last known New Zealand population increase). is under severe pressure from Ten captive-reared takahe yearlings from encroaching weeds, trespassing stock, Burwood were released at three locations habitat degradation and possible mineral in the Murchison Mountains in October. deficiencies. NIWA research contracts, Thirty-eight of the 49 pairs located in ex-situ growing trials, experimental the Murchison Mountains are known to habitat manipulation are some of the have nested. They laid 48 clutches, suite of tools being used to gain producing 80 eggs. Thirty-nine chicks information to halt the decline. While we hatched. Nine chicks and 1 egg were have had our successes, things have transferred to the Burwood Bush Captive looked fairly grim for S. ovata. Rearing Unit. Twelve were confirmed still However, while Justin Rehia (Taumaranui alive in the Murchison Mountains in Field Centre) and I were carrying out February. Six chicks were reared weed transects in Hawkens Lagoon, successfully on the islands this year. another coastal reserve, a likely looking Three of the 5 pairs at Burwood nested ephemeral wetland was noticed. A quick and produced 10 eggs. Six chicks were detour and subsequent search turned up reared from these eggs. A total of 15 an extremely healthy, vibrant population chicks were successfully raised at of Sebaea ovata. All plants in this small Burwood this season. area are in various stages of Between 30 and 45 takahe were reproduction. Immature, flowering monitored using radio transmitters in the (unusual for this time of year), and Murchison Mountains over the 1999/2000 seeding plants were all found. year. This work is aimed at assessing After a quick phone call, Colin Ogle survival and productivity differences (Wanganui CAS) arrived to confirm the between captive reared and wild reared find. Samples were taken for NIWA and takahe and determining causes of CHR. The immediate area was surveyed mortality. We have recently changed our but only turned up a large area of transmitter design following an pampas, which without immediate energetics study that showed significant control is likely to over-run this new plot cost for the birds in wearing transmitters. of S. ovata. A great find for the future of We will be preparing an article on this this plant, and it goes to show that it for the next issue of Rare Bits. sometimes pays to deviate from the line! Egg and chick production from 9 pairs in the McKenzie block of the Murchison TAKAHE PROGRAMME 1999/ Mountains, was intensively monitored for 2000 UPDATE the third year running. We have been from Dave Crouchley using temperature data logger eggs, time End of season figures show that total lapse video, and small chick transmitters. adult takahe numbers increased from 216 This takahe egg and chick mortality study last season to 221 (2.3 % increase). The is due to be completed in the 2000/2001 total number of adult birds on the four year. islands remained at 59 while the number The annual harvest target (140) for deer of adults birds in the Murchison control operations in the Murchison Mountains increased from 124 to 133 this Mountains was achieved with 146 deer year (7.2% increase), and the number of being removed in official control

RARE BITS No. 38. September 2000 16 operations. Increased effort in results of his work to help us design a monitoring and data collection since the landscape style stoat trapping 1996/1997 review of the programme has programme covering the SE sector of the enabled the calculation of population Murchison Mountains (14,000 ha). This estimates and harvest targets to achieve programme should help determine the a desired level of control. The good effect of stoats on the takahe population results achieved in the 3 years since the through a research-by-management review reflect the skill and hard work of approach. There should also be the contractors/operators involved, as considerable benefits for other species well as the improved planning and such as kiwi, mohua, and . increased resources. Monitoring of climate and mountain A stoat-trapping programme, aimed at beech seedfall in Takahe Valley has protecting nesting takahe, was continued. The 2000 autumn produced established in Mystery Burn, Point Burn, a moderate mast of beech seeding (high- and Takahe Valley. Ninety-two trap ish stoat numbers again next summer). stations were serviced between Five yearly re-measure of tussock September and May. A total of 149 stoats monitoring lines in Takahe Valley and were caught. This includes 30 stoats Chester Burn was completed this caught in three traps operated by summer. Travel staff at the tourist caves The takahe database has now been and some stoats caught during a radio- installed on the DoC Citrix network in tracking study in the Mystery Burn and Access format. Data checking and entry William Burn. Des Smith of Otago work to complete the installation of the University is undertaking an MSc study data from 19 years work in the Murchison in the area looking at home range, habitat Mountains has been a bigger job than use, and diet of stoats in the area. He expected. This should be completed by will be carrying out further fieldwork this end of September. coming summer. We plan to use the

Rare Bits is issued four times a year by the Biodiversity Recovery Unit (BRU), Department of Conservation, Tory Street, Wellington. Copy deadline for the next issue is 10 November 2000. Articles about threatened species management issues are welcome from anyone. Send them to the Editor, Rare Bits, BRU, Department of Conservation, PO Box 10-420, Wellington, in Word, on a floppy disk, or as an Email attachment (internet mail: [email protected]). Please follow these word limits: Conservancy News 800 words, Restoration Resumé 500 words, Island Roundup 1000 words, Other Bits 900 words, Feature Article 800 words. Articles should be clean (ie, free of any formatting) and any graphs or figures should be saved as TIF files. DoC staff can access Rare Bits through the S&R publications icon on the Intranet. Rare Bits can also be accessed through the department’s website - www.doc.govt.nz on the Internet.

RARE BITS No. 38. September 2000 17