Number 37 June 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 kaka research involved in threatened species recovery and from Ron Moorhouse ecological restoration Last summer was a watershed for kaka you can protect them. Once Fenn trap- programmes. In recognition of wider interest, however, research in Nelson Lakes National Park. lines were established we stopped “Rare Bits” is also provided We’ve finally monitored enough nesting localised nest protection so that we could to non-departmental groups attempts to answer the key question of evaluate this more widely applicable on request. The newsletter’s our research: can predator control method of control in combination informal style may reverse the decline of kaka? with the existing bait-station grid. occasionally lead to Baseline research by DSIR/Landcare in Six of the 8 nesting attempts completed misunderstandings for some of those readers. Views Big Bush Conservation Area documented since the establishment of Fenn trap-lines expressed by the authors are the previously appalling productivity of have been successful. The 2 nests that not necessarily those of the kaka there in the absence of predator failed did so because of predation on Department of control. Only 2 of 20 nesting attempts nestlings and , no female were Conservation. monitored over an 11-year period were killed. Even without including our first successful, producing just 4 young. Over season’s data, the difference between the same time period 4 of 7 radio-tagged these results and the DSIR/Landcare data females were killed on the nest by is so great that probability of it occurring predators, probably . by chance is only about 1 in 1000. To CONTENTS Three season’s data has now been exclude the possibility that we had struck FEATURE ARTICLE South Island kaka research 1 collected since the beginning of predator years of unusually low predator numbers SPECIES ROUNDUP control in the Rotoiti Nature Recovery we concurrently monitored kaka nesting Weta 3 Project (RNRP) area, literally just over success at (20 km from the Dactylanthus 3 the road from Big Bush. In the first RNRP area) where there was no predator CONSERVANCY NEWS season of our study a poison bait-station control. At the same time that most pairs Northland 4 Auckland 5 grid was in place to control rats and were nesting successfully at Rotoiti, 9 of Waikato 7 possums, but, because Fenn trap-lines 10 nesting attempts at Lake Rotoroa failed Bay of Plenty 8 for stoats were not yet in place, we used due to predation on eggs, nestlings, or East Coast/Hawke’s Bay 9 aluminium tree ‘bands’ and a ring of Fenn nesting females. The probability of this Wanganui 10 traps around each nest to protect these difference in nesting success between the Wellington 11 Nelson/Marlborough 14 from stoats. RNRP area and Lake Rotoroa being due West Coast 16 All four nests monitored that season were to chance is about 1 in 100. Otago 17 successful, fledging 12 young. While they From the population perspective it is the Southland 19 seemed effective, the localised nest predation of nesting females that is the OTHER BITS protection measures we used that season most damaging. Last summer alone we Successful bat skills workshop 20 are relatively impractical because you lost 3 of 5 nesting females to predators Argentine ant – a new pest? 21 Island Roundup 22 need to know where the nests are before at Lake Rotoroa. The RNRP area is a net producer of kaka, female nesting just outside the RNRP a marked turnaround from the appalling boundaries produced a clutch of 8 eggs, productivity figures recorded by DSIR/ twice the usual clutch size. Two females Landcare in the absence of predator resident in the RNRP area are currently control. Excluding last season’s fledglings renesting after fledging young earlier this which are still at risk of predation and year and another female at Rotoroa was those that we can’t find, 17 (61%) of the killed on the nest attempting to do the 28 fledglings radio-tagged at Rotoiti in same thing. Attempts to raise a second the previous two breeding seasons are brood in the same season have not still alive at present. previously been recorded in kaka. Although about a third of the young In January 1999 we transferred 4 female fledged have been lost to predators, more kaka from Whenua Hou (Codfish Island) than enough have survived to to the RNRP area in an effort to increase compensate for adult mortality which is our sample size. One of these nested last low (1 of 5 radio-tagged females at Rotoiti summer – only a year after her release. has died in 3 years, apparently of natural Unfortunately, her eggs and a recently causes). However, we may have to hatched nestling were preyed on, increase the size of the protected area if probably by rats, but the fact that she we are to achieve a local recovery of nested so soon after her release is kaka. At present, most of the young evidence of the adaptability of kaka to produced within the RNRP’s boundaries different habitats. Three of these birds disperse into surrounding unmanaged left the RNRP area after their release but habitat where they are unlikely to breed remained local. One subsequently died successfully. but the other 3 are alive and well. Since Since kaka bred in only 6 of the 11 years only 1 settled within the RNRP DSIR/Landcare worked in Big Bush boundaries it looks like it is possible to we’ve been fortunate that there has been reliably transfer adult female kaka into breeding every year we’ve been working an area of several thousand hectares but at Rotoiti. The DSIR/Landcare research not of several hundred hectares. revealed that nesting only occurred when We now have robust evidence that the beech seed was available. I thought there RNRP is working for kaka. If there is had been pretty big beech mast the breeding next season we plan to use previous summer but last summer’s time-lapse video gear to identify beech-seed crop was bigger still. This predators so that we can target these probably explains the unprecedented more effectively. productivity of kaka last summer. A

RARE BITS No. 37. July 2000 2 SPECIES ROUNDUP WETA ‘transferees’ had started to moult, so they from Andrea Booth (Northland), will be released when they have Jason Roxburgh (Waikato), and completed moulting, and when the John Lyall (West Coast) weather gets a bit warmer. Transfers Surveys for Deinacrida talpa, an alpine Auckland tree weta have recently been species, continued this summer with four released on Limestone Island; a 40-ha trips above the bushline along the scenic reserve in the upper Whangarei Paparoa Ranges locating a couple of new Harbour. After first listening for weta over sites. This followed on from last year’s several nights, weta were deemed survey, which extended the known range absent, probably owing to a century of north, and south along the range. No habitat removal, industrial activity and further work is planned. the presence of rats. DACTYLANTHUS Following the removal of rats and the from Bec Stanley (Auckland), Paul planting-up of the island over the last Cashmore (Bay of Plenty), and 10 years, it was considered viable to Graeme La Cock (Wanganui) release the weta into old remnant puriri What’s new? trees that could provide suitable roosting Two new sites for Dactylanthus taylorii sites. On-going monitoring of breeding were located by Graeme Atkins, Sid success will consist of artificial roost sites, Marsh, and volunteers on Hauturu in built by science students from Whangarei April. This brought the number of known Boys High School, and lengths of areas on Hauturu to 6, widely scattered bamboo capable of hiding juvenile weta. over the whole island. The research The Middle Island tusked weta (MITW), group was attempting to use kiore gut previously only found on Middle Island contents as a survey technique, because (Mercury Island Group), now has two possums, pigs, and rats are used on the new homes. Over a 2-week period, 150 mainland. It didn’t end up being a useful 4th instar MITW were released onto Red technique – we were surprised by the Mercury and Double Islands. These early flowering this year and so the islands are figured to give the weta their survey was a bit late, and also kiore greatest chance of establishing new seemed to chew the Dactylanthus quite populations, and will also indicate the finely and it was not visible in the optimal habitat of this species. stomachs. The new populations were The weta were welcomed to their new located by the old ‘look at the ground’ home by kaumatua of Ngati Tamatera, method. and have been monitored over the last A recent historic record of Dactylanthus few weeks. A perspex cover was was followed up in the Waitakere Ranges designed for the weta released onto Red with no success. The plan is to use the Mercury, to stop the risk of predation possum gut content technique next year by little spotted . Most weta have if funding allows. since vacated their perspex motels. In March staff were shown a new A few critters were released into a Dactylanthus site on the edge of the purpose built enclosure on Red Mercury, southern part of Whirinaki Forest Park and these will be monitored to adjoining Kaingaroa pine compartments. assess whether breeding occurs. At the Thirteen clumps were found growing in time of the release, many of the the narrow regenerating shrub margin

RARE BITS No. 37. July 2000 3 SPECIES ROUNDUP of horopito with scattered marbleleaf, were looking for woodroses, so he was wineberry, and broadleaf. There was surprised by the reply of “Oh you mean clear evidence that Dactylanthus Dactylanthus - we’ve got some”. True collection for woodroses had occurred enough there was this marvellous at the site. Staff returned to the site in population pretty close to where Taylor May and erected signage in the hope of is thought to have first found it. It was discouraging further collection activities. great to have Randel Springer, the Wanganui Conservancy decided to take historian who figured out where Taylor the idea of following up historical records probably found it, on our site visit, along to the limit - searching for Dactylanthus with hunters and field staff and Avi. I at the site where Rev. Taylor first found think the secret to this kind of trip is to it. Unfortunately everybody in conservancy have a population there to start with. and the area office who had any link to Monitoring the project had to be away during the Monitoring of Dactylanthus flowering at crucial planning phases, so it was left to Te Kopia and Pukerimu shows moderate Keith, a teacher on a year’s scholarship flowering this season with low levels of with DoC, to arrange the site visits with rat damage. At Te Kopia, even with low the farmers. We’d even lined up Avi to possum numbers following last winter’s give a talk to the botanical group the 1080 operation any uncaged flowers night before. were still destroyed. Keith opted to tell the farmers that we

CONSERVANCY NEWS NORTHLAND protected land. Staff are continuing to from Andrea Booth, Tom Herbert, search for new sites, and are also Steve McManus, Lisa Forester, Nicky recording threats at each site. These Syddall, and Gerry Brackenberry. include weed invasion and habitat Invertebrates destruction by stock and vehicles. Staff have been carrying out surveys for A new exotic wasp has been discovered the Northland species of the moth in the Far North, and identified by Jo Berry Notoreas. This is an undescribed species (LandCare Research) as Radumeris of brightly-coloured diurnal moth found tasmaniensis; a scoliid wasp known from only in coastal habitats. Its caterpillars Australia and New Guinea. The wasp has feed on sand daphne Pimelea prostrata. so far been found at two sites; both of Until recently it was known only from a which are sand dune areas dominated by handful of sites from West Auckland spinifex. In Australia, this wasp parasitises north to the coast west of Waipoua the larvae of scarab beetles, with the very Forest. Last November staff found large female wasps tunnelling into the caterpillars at two sites in the Far North: ground until they find the larvae. None these were reared by Brian Patrick of the wasp’s Australian host species occur (Otago Museum) and confirmed as being in , so DOC staff are the Northland Notoreas species. This was currently surveying the sites to determine welcome news because these records which scarab species are present. They have extended the range of Notoreas will also be searching for scarab larvae significantly, and both sites are on that have been parasitised by the wasp.

RARE BITS No. 37. July 2000 4 Kokako Hebe aff. acutiflora (Waima yellow) A pre-season survey of known breeding have been found - Warawara, pairs found 11 pairs still holding the same Maunganui Bluff, and Maunguru Range territories. A new pair was discovered (central Northland). Most interesting is holding a territory between the Waima Karen Riddell’s find of a strange tree and Waipoua populations. There were near Waima, which is thought to be only 3 nesting attempts this season: 1 close to Cunonia, a genus which would failed owing to a suspected harrier be new to New Zealand. Most Cunonia’s predation; 1 was suspected to have are from New Caledonia. infertile eggs (and was also suspected Kaitaia Area and Conservancy staff, to have been preyed on by a harrier); accompanied by two ‘Hebe’ experts from and the third was successful. This nest Te Papa museum, have discovered a new was from our most successful known location for the very rare Hebe perbella; breeding pair, and produced 2 chicks. previously known from only two sites. These chicks were translocated to Puketi, Just after one of the group stated that “it and were the only known kokako chicks should be in this forest”, staff discovered to be produced in Northland this year. the Hebe growing literally at their feet in Unfortunately, predators killed both Warawara Forest. A healthy population chicks within 2 months of their release. was found with many of them in flower The poor nesting results in our area were - a beautiful deep lilac colour. Plants were consistent with the poor breeding season found growing alongside tracks and experienced nationally this year. locations that people would have NZ falcon record repeatedly walked past in recent times. A dead NZ Falcon was recovered from a AUCKLAND property in the lower Waiare Valley, near The past summer season in the Auckland Kaeo at Easter this year. The had Conservancy fauna programmes been dead for a few days by the time produced the annual array of disasters the property owner found it on the back and triumphs for the staff involved in porch of his house. The last record of a management. A few of the more notable NZ falcon in Northland was of a single highlights were the best ever breeding bird near Russell Forest in the early season for hihi () on Tiri, a bad 1990s. season for Hunua kokako but good for Threatened plants Tiri kokako, and the challenges of the The autumn plants survey season has wind and tides for fairy tern at yielded some interesting records. There Papakanui. are now three sites for Schoenus carsei Kokako in Northland, now staff have their eye from Oliver Overdyck and Jason in for it! Another Baumea complanata Taylor site has been found, this time north of The Hunua kokako project with ARC Dargaville, bringing the total to four sites continued this year along with this in Northland from Te Paki south. season’s mainland predator control Grammitis magellanica supsp. challenges. Only 2 of the 4 pairs nothofageti was found in Warawara attempted to breed and both nests were Forest, a significant northern extension lost in incubation. Four Mapara females of the range of this plant. Three more were transferred in last season, and sites for a possible new upland hebe, although 1 had paired with a resident

RARE BITS No. 37. July 2000 5 CONSERVANCY NEWS male she had been killed during winter Hihi by a stoat. The other 3 females were from Jason Taylor resident around the core population for The Tiritiri Matangi Island population of 10 months then disappeared just prior hihi put on an impressive show this to breeding season. Although they had season. A concentrated management spent much time near other birds none regime of feeders, nest box management, of the male/male pairs split to take and fostering (where needed) assisted advantage of the female presence. At the in making this the most successful year end of this season 1 male, Hudson, yet. For the first time there were disappeared and has been replaced by successful third clutch fledglings. An Ting, a Hunua bred bird, in the pairing impressive total of 62 chicks were with Hall. This brings the total population successfully fledged this season. A post in Hunua to 19 birds including 5 male/ breeding survey (February) brought the female pairs. total population to 72 birds - a significant The 1 breeding pair of kokako on Tiri increase on the February 1999 count of again fledged 2 chicks this summer. The 47 birds. other single males on the island continue Argentine ants to be visible to the public as does the from Chris Green family group. Rei, a subadult from last Whilst on a routine trip to Tiritiri Matangi year’s nest success, was found killed by Island at the end of March Chris Green a harrier, and a second adult, Te Karere, discovered an extensive ant trail on a disappeared around the same period. tree near the wharf. Specimens taken Fairy tern were subsequently identified as from Lester Bridson and Sara Gibbs Argentine ants. Surveys of the island have This season proved to be the most revealed a semicircular distribution successful season for fairy tern nationally covering about 10 ha, or 5% of the island, for a number of years. Papakanui Spit and centred on the wharf. It appears site also successfully fledged 2 chicks to likely that the species has been on the contribute to the national total of 7 this island for at least a year, possibly up to season. High winds and the mobile 2 years. nature of the west coast dunes proved a Landcare Research currently has a challenge with one dune moving 4 m in contract with the department to study approximately 6 hours. aspects of the ant and has been testing a new ant bait from Western Australia. After from Shaarina Taylor discussing the invasion with Landcare This summer one pair of dotterel from and several overseas researchers, the Shoal Bay group proved their Auckland Conservancy has decided to adaptability by deciding to nest on a attempt an eradication of the ant from grassed island surrounded by motorway Tiritiri. Even though it was late in the on-ramps. Great protection from season it was initially thought that the predators but not so hot when the ants might still be susceptible to baiting. mowers came through. However, the However, recent tests in early June have goodwill of Transit, Serco, and the local shown this may not be the case so the council plus vigilant monitoring by local eradication will proceed in spring. OSNZ rangers enabled the birds to fledge Interim measures are in place to prevent 1 chick. its spread from Tiritiri to other islands

RARE BITS No. 37. July 2000 6 via stores and equipment on board WAIKATO supply vessels. See “Other Bits” for more Hauraki Area information. from Jason Roxburgh and Lance Threatened plants Dew (Project Kiwi) from Bec Stanley Lizards A natural spring in the industrial area of Time has been spent recently on Middle Onehunga is an unlikely threatened Chain Island (Alderman Group) plants site, but it just happens to be 1 of surveying lizards. Middle Chain is the 4 sites in the country for the rare aquatic only one of the five islands in the group moss Fissidens berteroi. This summer to have had rodents present, and we are water which fed the spring was required working to identify what species are to supply Auckland’s drinking water, and missing so they can be reintroduced. consequently the habitat of the moss was Surveys are timed to coincide with the not supplied with water. Some quick main seasons, and this trip found only action involving the regional council, Duvacel’s gecko. Earlier ones have found WaterCare Services, Landcare Research several other species. bryologist Dr. Jessica Beever, and the Kiwi local council resulted in some spring- Kiwi monitoring at the Coromandel Call side meetings. A temporary hose system Scheme sites is underway, with specific was established in time, we hope, to save emphasis on Whenuakite, near Tairua. the moss. A deluge of rain followed a An pest contractor has offered few weeks’ water supply, and the flow his company’s services for predator has now been restored. control at Whenuakite to protect kiwi, One single plant of mawhai Sicyos and we are intensively monitoring the australis has been relocated at Otuataua birds to map territories. Once this is done Stonefields, a recently protected reserve we will delineate an area, and the on the Manukau Harbour. One plant was predator control can begin. located here 5 years ago, but it died. This Good news on the Kiwi Zones’ front with individual is in another area of the the release of new funding for the five Stonefields, and seed was collected as a proposed Kiwi Zones. With one of the safeguard and sent to the Regional zones located at Moehau, Hauraki Area Botanic Gardens. and Waikato Conservancy Offices will be A covenant within the Carter Holt Harvey busy places over the next 12 months, managed forest at Woodhill was visited with staff getting the proposal into action. in May to inspect what was once our largest mainland population of Pimelea Project Kiwi (Kuaotunu Kiwi tomentosa. Unfortunately fallow deer Sanctuary) browse was extensive, and only 4 plants from Lance Dew, Project Kiwi Field were relocated. Management of the deer Team Leader is by a committee of recreational deer Kiwi Enclosure: The kiwi chick rearing hunters, however, it seems it is not to enclosure was formally opened on 19 the level where the threatened plants and February, and Tester, a 2-week old chick, the deer can co-exist. was liberated into the enclosure to test the ‘kiwi-proofing’ of the internal sub- division fences. Unfortunately, Tester died in strange circumstances several weeks after release.

RARE BITS No. 37. July 2000 7 CONSERVANCY The body was sent to Auckland Zoo for extend our trapping area to approximately NEWS necropsy. Despite its unusually low 3500 ha. weight and wasted appearance, the chick had been feeding. An unusual odour was Project Kiwi applied for a transfer permit detected in the chick’s crop, and the zoo to release weka from Pakatoa Island into staff were interested in getting a the core area of Kuaotunu in the toxicology report on the gizzard contents. Coromandel. Weka were present there DoC has offered funds for the test. Tester as recently as 15 years ago and would was from a 2- clutch, but its sibling be a welcome addition to the species (21 days older), was killed by a stoat list at Kuaotunu. Tony Beauchamp is about the same time. organising the transfer, which should Transit NZ: We have been working proceed once the proposal is accepted. alongside Transit NZ with our kiwi work Threatened plants since August 1997. Transit carried out Pimelia tomentosa and P. arenaria: intensive kiwi monitoring as part of the Several sites for these two species were RMA consents process for the widening visited and reassessed for threats. Most and sealing programme on State Highway of the threats are weed related, and are 25 between Whitianga and Kuaotunu. being controlled through current weed Several kiwi pairs interact with this stretch control workplans, or through simple of highway, and 1 pair’s territory straddles fencing. it. Sub-adult kiwi have been recorded Lepidium oleraceum: A large population crossing the road, and kiwi chicks have of L. oleraceum on the Matariki Islands lived on its margins. Only 1 kiwi was placed (Manaia Harbour) was revisited, and the at [minimal] risk during the roadworks kikuyu grass threatening parts of it was programme, which took place over a 6- controlled. This will allow the species month period. In this case the female was to expand into new habitat and ensure relocated on the day she was at risk. its survival on the islands. Trapping update: Since 1 July 1999 we have caught only 26 stoats, making it a BAY OF PLENTY fairly quiet season. We made a change from Paul Cashmore, Keith Owen, from real hen eggs to plastic eggs prior and Andy Blick to the start of the ‘busy’ season, and Ophioglossum petiolatum monitor the performance of this new bait Staff went to survey the newly discovered by continuing to use our Conibear traps population of the adders tongue fern baited with fat as a ‘control’. The NZ (Ophioglossum petiolatum) (Category O) Conibear traps, on their raised kiwi safe in Whirinaki Forest Park recently. sets baited with raw fat, have been our Because it was getting late in the season best trap set. However, most of the stoats some plants had begun to die off with caught recently were in Fenn traps baited many of the fertile spikes absent or dying. with plastic eggs. We have reservations The common O. coriaceum is also about relying totally on the plastic eggs present in this population which makes (or any one bait for that matter) and may identification more difficult, especially introduce other baits to the traps at towards this time of year. We did confirm intervals throughout the year to cater for that there are probably thousands of O. any dietary variations stoats may have. coriaceum plants present in the area, Recently a shipment of Fenn traps arrived however, we were only able to identify from England, and will be used to

RARE BITS No. 37. July 2000 8 a few O. petiolatum plants. A resurvey one record of NZ falcon was obtained. during summer will be required to Trap catch indices showed 23 possums confirm O. petiolatum numbers. Threats per 100 trap nights. As in other parts of to the population will be further the North Island, the distribution and investigated, in particular, the effect of numbers of North Island kokako and deer browsing on the population. North Island kaka have shrunk since the Mistletoe early 1970s. Further Tupeia antarctica plants have Whirinaki fernbird been located at Taumata Scenic Reserve Te Kooti composed a waiata called “Te while investigating road realignment Tangi o te Matuhi” (the call of the proposals. Approximately 6 new plants fernbird). Recently this waiata was the were found close to the proposed focus of a CD and book . On the CD is a realignment in addition to the 50+ plants John Kendrick recording of a fernbird already known from the area. call which was used to conduct a small A new local host for Ileostylus fernbird survey before and after an micranthus has been found at Okere Animal Health Board 1080 aerial carrot falls. In addition to the known Ileostylus drop in the Whirinaki . specimen growing on hawthorn a young A road, crossing a frost flat, was used as plant was discovered hosting on a access to monitor birds living in the Muehlenbeckia australis vine. Another monoao dominated shrublands on either Ileostylus plant has also been found on side. Three evening surveys (in February, the edge of Lake Tikitapu. April, and May) were conducted prior Pittosporum turneri to a 10 kg/ha carrot operation. Totals Staff have recently remonitored the for these were 12, 10, and 8 individual health of the Pittosporum turneri birds. Timing was found to be critical, population in southern Whirinaki. This the response to taped calls being best annual survey again showed an absence between sunset and dark. of any mature adult foliage or any Eight days after the poison drop the road seedlings. was re-surveyed. Nine birds were noted as responding to the calls. At this stage Opuiaki Ecological Area bird it appears that 1080 has had a limited survey effect on the fernbirds living in this frost- A bird survey of the above area has just flat . It is intended to continue monitoring been completed. The primary focus of call rates at least twice more in the the survey was to determine the coming months. distribution and approximate density of This information has already been useful North Island kokako, and to carry out a in advising agencies involved with a large survey for juvenile kokako. Eighteen TB possum control programme in the indigenous and 6 introduced bird species Rangitaiki/Kaingaroa area. were recorded within the survey area. Four threatened species - NZ falcon, NZ EAST COAST/HAWKE’S BAY pigeon, North Island kaka, and North Boundary Stream Mainland Island kokako - were recorded. A total Island of 48 kokako comprising 13 pairs and from Steve Cranwell 22 singles was detected during the The reintroduction of North Island brown survey. No juveniles were found. North kiwi into the Boundary Stream Mainland Island kaka were uncommon, while only

RARE BITS No. 37. July 2000 9 CONSERVANCY Island continues with the release of a Blue ducks released in Egmont NEWS second bird. The weight of the 2 birds National Park at release have been 1150 and 850 g Intensive monitoring of the released birds respectively. Over the 2 + months since has been regularly undertaken. Some of Ari’s liberation he has continued to the captive-reared birds have been lost fluctuate around the release weight. At through starvation, not from a lack of 850 g it is believed Raina will adapt more food resource. We assume the birds quickly whilst being sufficiently large to starved because they did not know how fend off the unwanted attentions of to forage for aquatic invertebrates. Other stoats. A third release occurred at the birds have succumbed to predation from end of May. The bird released, Kohu, stoats or ferrets, and one of the wild- was 1000 g. The condition and caught birds was run over by a car (can movements of all birds will continue to you believe it!). All the captive birds lost be monitored. weight initially, which resulted in In an effort to enhance the effectiveness transmitter harnesses becoming loose. of predator control regimes a couple of Without harnesses monitoring of the experimental initiatives have been added birds required significantly more effort. to the suite. Trapping for mustelids has All the casualties occurred within the first been supplemented with a purpose- 4 weeks of release, and there have been designed poison egg/trap box, which no further losses since then. This implies delivers 1080 injected hen eggs for stoats that the remaining birds are true and a Diphacinone Ferret paste. Changes survivors, although the threats to adult in trapping rates, tracking tunnel indices, birds from introduced and native and autopsy results will be used to assess predators remain. the effectiveness of this method. A Despite the losses to date the results are rodent-based form of Cholecalciferol encouraging. The knowledge gained (Feracol) is being trialed in a section of from the experiment enables us to refine the reserve as a means of achieving future releases to significantly increase sustained rat control. The toxin will be survival chances, which will ultimately evaluated over the next couple of months assist in re-establishing a population of for its effectiveness in maintaining rats blue ducks. below a 5% tracking tunnel index. Powelliphanta “Egmont” WANGANUI Additional surveys have been undertaken this year resulting in some minor range from Tim Holmes, Graeme La Cock, extensions. Re-surveying has turned up and Rosemary Miller similar numbers of snails compared with Celmisia “Mangaweka” a survey done 5 years previously. This In the last issue we reported germination indicates that the population is stable. failure in the seeds that had been Short-jawed kokopu collected. A request was received for The 6-monthly tagging of the short-jawed more seed, so Henry Dorrian collected kokopu was conducted at our two study some of the remaining scraps. We now sites. Seventeen fish were caught of which have over 50 specimens to plant out later 12 were recaptures and 5 were new fish this year, thanks to Robyn Smith at to the area. Growth rates appear to be Percy’s Reserve. greater than in the past with 1 fish having grown 25 mm since November 1999.

RARE BITS No. 37. July 2000 10 Surveys for spawning sites were team for assisting this busy and conducted, following last year’s demanding programme. significant find of a koaro spawning site, Black robin and three fish ‘nests’ were discovered. The black robin season was a mixed one Evidence suggests that these sites might with an average season on South East belong to short-jawed kokopu. Eggs have and a poor season on Mangere. The been collected and will be sent for established intensive monitoring genetic analysis to confirm which species technique (following all breeding they belong to. If any of these sites are attempts/banding all fledglings) on South confirmed to be short-jawed kokopu it East was down-scaled to include trialing will be the first spawning site ever ‘distance sampling’ as a measure of discovered for this species! Watch this population density and health and also space! following a sample of pairs to keep an WELLINGTON eye on productivity. Incidental sightings of banded robins were also recorded from Shaun O’Conner over the season. A total of 116 banded Chatham Islands staff individuals were sighted between development programme September and March over 99/00. The overall season results achieved for Productivity of 14 pairs was monitored the Chathams offshore islands threatened from 3 selected habitat types with results species programmes on South East and of 18 fledglings reaching independence. Mangere Islands are highlighted below. Productivity was 64% (chicks fledged These achievements are in large part due from eggs laid) from the monitored to the dedication and hard work put in sample. Twenty-eight yearlings (from the by contract workers Helen Gummer on 116 sightings) were recruited into the South East and Tertia Thurley on population. Mangere. Both these skilled operators co- On Mangere Island intensive monitoring ordinated the hands-on fieldwork and continues in tandem with the new supervised staff development participants distance sampling technique for on 5-weekly team rosters on each island calibration. The population started the through the season. season on par with previous years with The following people participated in the 48 birds in the available robin bush staff development programme and share habitat. However, productivity was only a stake in these results: John Neilson, 16% with 8 fledglings reaching Brenda Oldfield, Maureen Burgess, Sylvia independence. Egg and chick failure was Watson, Mike Brown, Roger Elliot, very high, clutch sizes small, and the Babara Couden-Oches, Mike Bell, Fiona season finished early with moult Bancroft, Phillipa Gardener, Sid Puia, underway by late December/early Clayton Ross, Don Merton, Thelma January. Last year 24 chicks reached Wilson, Jaap Jasperse, Henriette Beikirch, independence from the same area of Pete Shaw, Eddie Te , Emma Ross, habitat. Potential threats such as Adrian Couchman, James Smith, Jim introduced predators and disease was not Searle, Shelly Harvey, Bruce McKinley, apparent. Perhaps a crash in food supply Mark Kearney, Phil Crutchley and is responsible? Seventeen yearlings were Richard Parrish. Thank you all! Thanks recruited into the population on also to the area office team and Mangere. Preliminary analysis of the conservancy office technical support

RARE BITS No. 37. July 2000 11 CONSERVANCY distance sampling trial has shown a Chatham Island petrel NEWS higher estimate of density than the actual Progress in Chatham petrel recovery was known population figures. The friendly outstanding this season. A total of 59 new nature of robins (having been habituated Chatham petrel burrows were found to humans feeding mealworms) is the through a combination of telemetry (49 likely cause and is being grappled with burrows) in November/December, and by Rod Hay of SRU. as the season progressed by random Forbes parakeet search (3 burrows), following adults (6) Forbes parakeet received serious and chicks (1) as new birds on the attention this season on Mangere Island ground. Total active burrows for the with the start of a combined field ecology season was 120, with 100 going on to and nuclear DNA study on the species show breeding behaviour. The breeding and its hybridisation with Chatham Island burrows returned a success rate of at least red crowned parakeet. Efforts 72%. A total of 301 Chatham petrels were concentrated on capture and banding for ‘processed’ this season, 228 recaptures mark/recapture research, erecting nest and 73 new birds. As a comparison, in boxes, location and monitoring of natural the 1998/99 season, 72 active burrows and artificial nests, collection of genetic were known, 54 showed breeding material for the DNA work, and behaviour and achieved 78% breeding collecting baseline morphometrics and success. Telemetry and random photographic records of plumage searching in 98/99 found 7 new burrows. variations (hybrid index) from Forbes, The 98/99 season, however, was a quite red-crown, and hybrid parakeets. Sixty- one on the prion front. This season saw six adults and 39 nestlings were a return to a more typical/ average prion individually colour banded and the year with large numbers returning to the above information collected. Nest island during the prospecting period and monitoring revealed a very low hatch competing with Chatham Island petrels rate (30%) but high fledging success for breeding burrows. Prion counts (chicks fledged from eggs hatched) at peaked in Woolshed Bush at 483 birds 47% compared to other parakeet species. in March, with the most intense Nest boxes in the revegetating Douglas prospecting period (in terms of higher Basin shrubland recorded a second year counts) being late February to mid April. of very high egg infertility at over 50%. As this pattern emerged and with the The total parakeet population (both higher number of new burrows to protect species and hybrids) on Mangere was this season, extra staff were recruited estimated at between 500-700 birds, with through the staff development the real question still being – how many programme to form protection teams to hybrids are there? Researchers at Victoria patrol the petrel burrows at night and University have found that hybrids may cull prions interfering with Chatham be cryptic in plumage variation, which Island petrel burrows. potentially undermines the current Shore plover hybrid-rating index. Nuclear DNA It was an average season on South East markers are therefore urgently needed Island where storm events were responsible to identify the real extent of hybridisation for failure of a significant number of and its threat to Forbes parakeet. nests, particularly on the northern coast. The breeding success of 14 pairs associated

RARE BITS No. 37. July 2000 12 with a colour-band trial on the northern programme to streamline staffing, coast was followed with 31-38% fledging resourcing, and logistics. Richard success. The trial of double wrap-around Goomes and Georgie Hedley undertook colour bands sealed with solvent the daily fieldwork. Management (tetrahydrafuran) has successfully includes predator control, stock completed 3 seasons. exclusion, and nest manipulation One problem, picked up during the trial, (protection from high seas) in 16 was related to the habitat in Whalers Bay territories on the northern coast of main where mineral deposits on the rock Chatham. Twelve unmanaged (non- terraces began ‘growing’ inside the band, treatment) territories were monitored on sealing them to the legs. Bands were main Chatham as a measure of the removed and will not be fitted to effectiveness of the combined territorial birds in this habitat in the management regime in the managed future. territories. Mortality of banded birds through the Results have been very promising. In the trial compares favourably with previous managed territories 25 chicks fledged and survival data from Alison Davis’s study reached independence from 16 pairs, on the population. The breeding activity and in the unmanaged territories no of 23 other pairs on the island was also chicks fledged from 12 pairs. Results of followed early in the season as potential the video surveillance showed that donors of chicks for reintroduction to predator and disturbance events were 5 Mangere Island. Unfortunately the times greater in unmanaged territories reintroduction had to be postponed a versus managed territories. Three fatal week prior to transfer when the holding predation events were recorded on video aviary on Mangere was destroyed by a in unmanaged territories – 2 clutches of storm, and staff lined up to provide eggs were predated by a cat and 1 clutch avicultural care for the birds had to return of eggs predated by a weka. Several nests to NZ. Another attempt will be made in were lost to high seas in the managed the coming season. territories despite shifting nests away The biannual census on South East has from the wave zone. Numerous ‘close shown a significant sex imbalance in calls’ were recorded on video including favour of males for a second season cattle and sheep trampling, weka, and running. The banding programme over harrier disturbance. the next 3 seasons will aim to identify The predator control regime focused on which theory on the bottleneck for trapping which yielded 51 cats, 719 females is evident. weka, 61 possums, 44 rats (despite not Chatham Island oystercatcher targeting rats), and 41 hedgehogs over 5 Chatham Island oystercatcher recovery months. The overall capture index was received a welcome boost with the 0.068 captures per corrected trap night. beginning of a 4-6 year research project Sixty seven oystercatchers have been led by Peter Moore. It will investigate colour banded in the last 2 seasons, the causes of nest failure, assess the including all fledglings from the managed effectiveness of predator management territories in both years, to enable via video surveillance, and research key research on survival, dispersal, population dynamics. The research is recruitment, and turnover of adults in being run jointly with the management breeding pairs. The total population stands at approximately 150 birds.

RARE BITS No. 37. July 2000 13 CONSERVANCY Taiko NELSON/MARLBOROUGH NEWS from Mike Ogle Fishy bits Six taiko chicks have successfully fledged There was an outbreak of Gambusia, the this season. This is the highest number mosquito fish, near - the first of chicks known to have fledged since outbreak for the South Island. This active management of taiko began. species is a threat to indigenous fresh Transmitters were attached to all chicks water fish values. The offending pond before fledging. (Not all burrows have was treated with Rotenone poison, and study holes for easy access so this at this stage we appear to have got them required several nights waiting for chicks all. We will be doing more follow-up to come out - usually about 2am.) The work soon to see if the species is in fact transmitters were attached so that chicks more widespread. could be monitored and relocated if they The survey for short-jawed kokopu in did not make the 4-6 km journey to sea. the Marlborough Sounds has now been Three chicks made it successfully on their completed with the discovery of 20 new first attempt. Two were found outside populations using spotlighting and re- their burrows once and returned to their confirmation of 7 existing populations. burrows from which they later A number of new giant kokopu successfully fledged. One chick however populations were also discovered, and failed to fledge twice. The second time banded kokopu appear to be present in it was found its weight (390 g) was below nearly all Sounds streams. Combined the previous lowest known fledging with last year’s survey results from Abel weight (400 g) and well below expected , the top of the south is proving fledging weight (470-480 g). This chick to be a stronghold for short-jawed was taken to the coast that evening and kokopu. Over the last 2 years of survey placed on a hill side, from which it work, a total of 282 fish have been confidently departed. recorded, which surpasses the entire Two of this season’s chicks were from national number of short-jawed kokopu previously known burrows, while 4 were recorded in the Freshwater Fish Database from burrows located during the highly (220) up to 1996. We wait with interest successful telemetry operation earlier in the results of other conservancy the season. A 7th egg was laid this systematic spotlight surveys! season, also in a newly discovered Interviewing local eel fishermen led to burrow, but unfortunately failed just the discovery of a number of new before hatching. The survival of all 6 kokopu populations. The presence of hatched chicks through to fledging was giant kokopu in the river draining thanks to the extremely determined effort Waikoropupu Springs was a really put in by field staff to protect the interesting piece of information given the breeding burrows from cats, possums, large salmonids that reside within this weka, and rats. A total of 92 cats was river! trapped from around the taiko burrows Fowl behaviour this season. We now have to wait for at Maudie, the matriarchal takahe from least 4 years before this season’s cohort Maud Island, has had a rough year. She of fledglings hopefully returns to the has been well and truly bashed up by colony in the Tuku Nature Reserve and her daughter-in-law and after an adjacent private land. expensive sojourn with the vets is now

RARE BITS No. 37. July 2000 14 back in solitary confinement on the daisy jumper, Kiwaia sp. This is a tiny island. It seems there are two options brachypterous (reduced wings) moth for her – to pack her off to some safer which was discovered there only last location or to import some young stud year. So far this species is known only to keep her safe and well served. Her from a very narrow (20-30 m maximum) time in town raised much interest from strip, less than 2 km long, just behind the media, which is continuing to follow the active beach where it is associated her fate. with Raoulia mats. Thirty adults were Buggy bits counted in total. Potential habitat further Survey work on Arapawa Island south near Kekerengu was also searched confirmed the presence of the protected, without success. There is very little undescribed Megadromus beetle at habitat left in Marlborough that this several sites, as well as Wainuia and species could occupy. occasional Powelliphanta snails. Planning However, in many areas these species Considerable conservancy resources are are being heavily hit by pigs which have being spent in the Environment Court severely rooted large areas of forest floor, battling a rash of new marine farming overturning large stones in the process. applications. The impact of existing and The invertebrates tend to be surviving proposed mussel farms on king shags in where there is substantial bedrock the Outer Sounds has become a key issue outcropping that curtails pig activity. and the pressure is on to quantify this A survey in the Cobb valley area showed effect. In Golden Bay the impact of inter that the isolated population of Rhytida tidal cockle harvesting on shorebirds is stephenensis in Thorn Creek seems to another concern. be thriving under the cover of marble Research talus. Unfortunately the same cannot be The unprogrammed scientific advice said of the largest Rhytida species, R. fund has been used to good effect to get oconnori, in the Canaan area north of advice on a couple of management Takaka Hill. Although large numbers of issues. Josh Kemp did some excellent shells were found, including just beyond research into the impact of stoats on the area to which Murray Efford thought Huttons shearwater during and after a they might now be confined, almost all heavy seeding of tussock. Belinda of them had been recently eaten by rats. Studholme is reviewing what is known A number of shells were found at typical of the distribution and abundance of ship rat ‘husking stations’, along with the rats in South Island beech forests and remains of giant pill millipedes. Only a how this might change between years. couple of live juveniles were found in 2 This work was prompted by the days’ searching by three people. disastrous year for mohua on Mt Stokes Two searches of the Canaan area for rare following an irruption of rats. ground beetles resulted in the finding of Flora a quite dense but localised population A recent South Marlborough survey has of the large carabid Mecodema costellum turned up a new record of obesum. A single specimen of the smaller Muehlenbeckia astonii and re-found M. strictum was also found. Carmichaelia vexillata in the Awatere In April, the Cloudy Bay foreshore area Valley. The latter hadn’t been seen in was searched for the undescribed mat Marlborough for over 60 years, and given

RARE BITS No. 37. July 2000 15 CONSERVANCY the modification of the area over this time WEST COAST NEWS was a pleasant surprise. from Paul van Klink, Jo Crofton, During an initial inspection of the newly Chris Rickard, Ron van Mierlo, acquired forest in Golden Megan Hieatt, and Martin Abel Bay, area staff Simon Walls and Greg Weka monitoring Napp discovered a small population of Possum control is occurring in parts of the critically endangered coastal cress the Karangarua and Copland Valleys; Rorippa divaricata. It makes this site the both of these valleys hold the southern- second-known locality for Rorippa in the most populations on the mainland of South Island, the other one being western weka in the conservancy. As part recently discovered along the Abel of ongoing monitoring of the effects of Tasman coast. Around 12 plants have 1080 on non-target species 15 adult weka been found, some of which are browsed were captured in the Copland Valley and - possums are implicated although goats had mortality transmitters fitted in are also present in the area. December 1999. This year’s survey of the Te Tai Tapu Pre 1080 weka monitoring has been coast turned up some excellent rare plant carried out every month to date. Four finds and coastal turf communities. The dead birds have been found in recent best populations in Nelson of creeping months. The first 2 birds found near the iris (Libertia peregrinans), sand tussock Welcome Flat hut were too decomposed (Austrofestuca littoralis), and shore to establish their cause of death. Two spurge (Euphorbia glauca) were found, more birds found last week showed the along with one of the largest coastal cress cause of death was predation. Both had populations in NZ - over 110 plants, as puncture wounds on the back of their well as the only known wild plants of skulls. Stoats are presumed to be the NZ spinach (Tetragonia tetragonioides) likely predator. Post-monitoring results in the northern South Island. will be presented in the next issue of Three more small populations of the Rare Bits. critically endangered pygmy button Okarito kiwi (Leptinella nana) have been found A total of 20 adult pairs were monitored during a survey for it along the Rai River. during the previous season, and we had The total number of populations in the the options of removing either eggs or conservancy is now six, all along a 1- chicks for Operation Nest Egg (ONE). km length of the Rai - and covering a Twenty-four eggs were detected and 11 total area of no more than a table top. removed for artificial incubation. Of the The biggest threats are weed competition remaining 13 eggs, 8 hatched in the wild, and loss of riparian forest habitat. We and 5 failed to hatch. Overall, it has been discussed options for legal protection a productive year with a low loss rate, with Nicky Eade of Marlborough District probably owing to removing more eggs Council because all of the populations for incubation than in past seasons. The are on road reserve administered by the current group of 20 breeding pairs being council. monitored, however, is biased towards good producers. A number of non- productive adult pairs have been dropped from the management population.

RARE BITS No. 37. July 2000 16 This has been a successful year for noting hydrology, probing peat depths, released ONE birds. Currently a total of and identifying potential threats. This 17 ONE birds are now being monitoring. work contributes to a continuing West Two ONE birds are sheltering with wild Coast wide effort to assess and quantify birds of the opposite sex, and there seem relative wetland values to decide future to be some other potential pairings management priorities. Plant records of between ONE birds. We have yet not note for the summer include detected any breeding and are hoping Deschampsia caespitosa at the northern for more success on this front in the end of Okarito Lagoon (last recorded upcoming breeding season. The oldest there in the 1980s), Drosera pygmea, a ONE bird (Moonshine) is now 4+ years new record for this species from South old and has been in the wild for 3 years Westland - also at north Okarito Lagoon. & 4 months. Korthasella var. clavata was found at Three ONE birds have died during the Five Mile Lagoon - parasitising Coprosma year. Bobbit and Claudette died as a propinqua, well outside its known range result of territorial confrontations. Bobbit at Castle Hill basin. was almost certainly killed by another Bats ONE bird while her parents killed A follow-up survey in Paparoa National Claudette. Cuba was hit by a car and Park for short tailed bats, inland from killed. Two other juveniles lost their Punakaiki failed to record any passes. transmitters during the year because of We were attempting to reconfirm the very harness failure. We hope that our new sparse records from the previous season. harness system will eliminate this frustrating occurrence. OTAGO Freshwater surveys from Bruce McKinlay, John Barkla, Indigenous fish surveys are underway and Jack Van Hal around Franz Josef to improve Mohua, Dart Valley knowledge about brown mudfish and Between October 1999 and February other species’ distribution in the area. 2000 mohua nest monitoring occurred So far this year, brown mudfish have only in the Caples and Dart valleys in the been caught as far south on the West Wakatipu area. This was part of a stoat Coast as Forks Pakihi, in South Okarito control study also involving the Eglinton Forest. Previous records exist from here Valley in Fiordland. The Caples was used also. Efforts to locate this species further as the control site, where no predator south continue. Banded and giant control was carried out. We hoped to kokopu have also been caught in the find a significant difference between the Okarito Lagoon catchment, and at Three valleys. The results were interesting. and Five Mile Lagoons. Earlier in the year Five diligent workers went out fully laden healthy numbers of short-jawed kokopu with mist netting and banding equipment were confirmed by spotlighting a section into the respective valleys. After a couple of Zalas creek, north of Franz Josef. of weeks of ropes and mist net hauling, Wetland surveys of Three Mile, Five Mile, we managed to band around 120 birds. and Okarito Lagoons were undertaken Nest finding provided more challenges this summer, mapping vegetation because several pairs of birds were found patterns, and noting fish, bird, plant, building up to 4 different nests on the weed, and introduced mammal species same day! Eventually 72 nests were present, as well as taking water samples, closely monitored, 37 spread over two

RARE BITS No. 37. July 2000 17 CONSERVANCY sites in the Caples and 35 throughout Caples, Lake Sylvan, Borer Flat, and Mill NEWS four areas in the Dart. Whenever possible Flat. Several other bird species were also trees were climbed to monitor nesting noted in the area. Kaka were heard stages and measure nest holes. regularly at Upper Caples from December Of the total 54 breeding females, all onwards, also the very occasional , survived the season. A large portion of shining cuckoo at Mid Caples, and a pair nesting did occur during the predation of falcons living not far from the hut. risk period, i.e. after December when the Even were reportedly heard juvenile stoats leave their dens. There in the Kay Creek catchment. All-in-all a was a 69% success rate in the Caples thoroughly interesting and enjoyable and 80% in the Dart. There were various season was had by all involved. reasons for these nest failures including Pittosporum patulum the November floods, abandonment, Wanaka Area and Conservancy staff predation, and long tail cuckoo spent a few days searching the mid and parasitism. Out of the 12 failures in the upper Hunter Valley (head of Lake Caples and 8 in the Dart, 15 were owing Hawea) in May for Pittosporum patulum. to an unidentified predator, 2 were It is in the adjoining Dingle Valley, and known to be long tail cuckoo predation the Hunter was recognised as the most and another 2 nests were victims of likely prospect for expanding its known cuckoo parasitism but are not considered range. Despite finding lots of ostensibly failures because the cuckoo nestlings suitable habitat no new sites were found. were successfully fledged. Tree daisies A long tail cuckoo was observed visiting Stu Thorne from Wanaka Area has been one mohua nest at Upper Caples surveying the lower and mid Matukituki containing 2 nestlings. The cuckoo Valley for Olearia hectorii to get an arrived immediately after the adult left accurate census of the population and the nest, entered the hole for about 30 to identify the best sites for future seconds and crawled out backwards with management. Several hundred trees are a chick in its beak and promptly left the known from the valley but many are area with it. Upon re-inspection of the lonely individuals or small groups out nest, only 1 nestling remained. The in farmland with little conservation following day the other nestling was also prospect. The valley is a real “hotspot” gone and the nest empty. This pair did for Olearia with 3 threatened species later have another nest which present (O. hectorii, O. frangratissima, successfully fledged, but this observation and O. fimbriata) plus more common may explain several of the other species including O. odorata, O. lineata. mysteriously emptied nests, at both egg Not too far away at Hawea Geoff Rogers and nestling stage, where there was no found a population of Olearia fimbriata other sign of predation and/or with good survey prospects nearby. disturbance. Scree pea By the end of the season we had 2 pairs Jim Henderson from Central Otago Area of mohua raising one long tail cuckoo has recently set up some small exclosure each. It’s interesting to note that one nest plots in one of our better Montigena was 70x45 mm which may be the (=Swainsona) novae-zelandiae sites on smallest size recorded to be parasitised the Hawkdun Range. There’s a strong by a cuckoo. Long tail cuckoos were suspicion hares are browsing it, heard almost daily, all day long at Upper

RARE BITS No. 37. July 2000 18 preventing seed production, so the Recent trapping on Whenau Hou exclosures (with non treatment sites) (Codfish Island) following the bait drops should help to clarify if indeed there is a on that island in August 1998 also found conservation problem. no sign of rats. That eradication will not Odd finds be declared a success until the initial Dean Nelson reports that two recent proposed monitoring regime (i.e. recoveries may be of interest. A Snares trapping around feeding stations) cape pigeon was washed up at Long can be put into place once the feeding Beach. It was banded as an adult male programme starts up again (probably in November 1986. The other was a titi later this year). found dead at Taieri aerodrome, which Bird transfers was banded as an adult on Motunau The fernbirds which were transfered to Island on 24/10/76. Young birds don’t Putauhinu from Whenua Hou as part of return to their natal colony until 3-4 years the preparations for the eradication on old, so this one could be potentially 27+ Whenua Hou and as part of the post years old. eradication restoration on Putauhinu Taiaroa Head have done very well and are rapidly Sharyn Hellyer has been working up building up numbers. While the bait drop trapping data from Taiaroa Head, and on Whenua Hou certainly knocked the so far she has entered 104 months’ data. fernbirds they are now starting to show The variety of trap types and sets used their heads above the manuka again and over the years is quite varied, as is the with breeding confirmed this season, it number of target animals. We hope to currently appears that we will not need be able to identify much more closely to transfer any birds back from where on the headland trapping is Putauhinu. successful and for what type of predator Transfers of Stewart Island robins to and for which type of trap set. Putauhinu and Meeweka (banded rail) to Kundy Island both as part of the SOUTHLAND ongoing restoration of those islands from Pete McClelland, Eric Edwards, appear to have been successful according and Lyne McFarlane to the muttonbirders who reported Southern Island Area breeding this year. Rat eradication Another 12 Campbell Island teal have Following monitoring on Raratoka been released onto Whenua Hou and (Centre Is) and Putauhinu - the later appear to be settling in well despite some being largely carried out by the boundary disputes with the locals. muttonbirders on the island in April/May Invertebrate surveys - no sign of rats has been detected. Both Campbell Island: Lowland sites were islands had Brodifacoum bait dropped recently surveyed for large bodied weevils on them in August 1997 to eradicate including ribbed weevil Heterexis kiore, and it appears that this has been seticostatus (Cat B) and weevil successful. Given that it is three breeding Oclandius cinereus (Cat I). There was seasons since the drops and the islands no sign of ribbed weevil (common in are relatively small (88 and 144 ha the late 1940s). Hopefully populations respectively) we can now declare the remain on nearby islets or possibly at eradication a success. higher elevations. Only remains were

RARE BITS No. 37. July 2000 19 CONSERVANCY found of Oclandius cinereus. It is likely O. stenotis, O. nigriplantare polychroma, NEWS it persists in low numbers on parts of and O. notosaurus). This species has Campbell Island and should respond only been recorded on outlying islands well to planned Norway rat eradication. of Stewart Island/Rakiura. Research by Auckland Islands: Lowland sites were Lyne McFarlane on H. rakiurae surveyed in the Port Ross area and (Harlequin gecko) is still underway on Enderby Island for Auckland Island Stewart Island with the first summer weevil Oclandius laeviusculus (Cat C) season completed. These geckos are and again for O. cinereus. There was no being studied at two sites in the southern sign of O. laeviusculus. Remains and one part of the island. live individual of O. cinereus were found Murihuki Area in Port Ross. Visits to Tikore (Spensor Island), Tihaka Snares Islands: Janice Molloy and team (Pig Island), and Rarotoka (Centre Island) searched for Broughton Island weevil over the summer recorded 2 skink species Lyperobius nesidiotes and found no sign (Oligosoma nigriplantare polychroma on Northeast Island, but knobbled weevil (Tikore) and O. inconspicuum (Rarotoka, Hadramphus stilbocarpae (Cat C) were Tihaka) and 1 gecko (Hoplodactylus noted. The adjacent Broughton Island is “Otago”, Tihaka). The geckos were the only known site for L. nesidiotes and found under the only rock slab on the has not been surveyed for some years island, possibly the only protected place (possibly not since 1976). from weka which are also present on Lizards the island. A 2-day survey in Garston The recent discovery of Hoplodactylus searching for the elusive Garston skink nebulosus (the cloudy gecko) on Stewart revealed plenty of O. maccanni and a Island/Rakiura increases the lizard slough of a gecko. However the Garston fauna to 6 (Hoplodactylus rakiurae, skink still remains undetected. H. nebulosus, Oligosoma chloronoton,

OTHER BITS SUCCESSFUL BAT SKILLS projects. The participants were able to see WORKSHOP real applications of the work, and the work from Colin O’Donnell was useful to the department at the same Twenty-six people attended a bat skills time. The workshop was very intensive, training workshop at Knobs Flat in the with night work (usually 1900-0100 hrs) Eglinton Valley from 31 January to 4 and day work (usually 0500-0900 and February 2000. This followed a similar 1300-1800 hrs). course in the North Island in 1988. The The main emphasis was on the key tasks aim was to improve staff skills for bat that managers need to address in their survey, monitoring, and management in areas, specifically: their areas. We were lucky that we had • establishing if bats are present good weather and caught both species of • identifying the species present bat (short-tailed bats and long-tailed bats). • monitoring their population trends, and Training was combined with undertaking • identifying key habitats for protection Science & Research Unit and Te Anau Area or management (roosting and foraging Office bat research and monitoring habitats).

RARE BITS No. 37. July 2000 20 All participants were trained in trapping Argentine ant has several attributes that bats (harp trapping and mist netting), make it much more successful than other handling bats (including measuring and ants. A key feature that sets the species weighing, banding (long-tailed bats apart from most other ant species is that only), attaching transmitters and taking workers from neighbouring Argentine wing biopsies), surveying bats (use of ant colonies co-operate with each other. bat detectors, identifying species from Thus when a new food source is located, their echolocation calls, undertaking such as a tree coming into flower, all transect surveys for long-tailed bats, surrounding nests will be able to partake. using a variety of automatic detector Because it is a very active, fast moving systems, planning distribution surveys ant it often locates new food sources and long-term monitoring programmes), ahead of other species and can thus more operation of infrared video equipment efficiently dominate all available sources at roosts, radio-tracking bats (following in the area occupied. The species also active bats and finding roost sites), and features a highly developed chemical tree climbing (demonstration only). defence secretion, which will force the retreat of most other ants, even when ARGENTINE ANT – A NEW PEST? these other species are much larger than from Chris Green Argentine ants. Thus, despite their small The Argentine ant is native of South size, Argentine ants frequently win one- America and has been invading overseas on-one contests. countries for more than 50 years, Unlike virtually any other ant species in including North America, Hawaii, South New Zealand Argentine ant trails feature Africa, and Australia. It was first recorded huge numbers of ants, moving in a in New Zealand in 1990, just before the stream up to 5-6 ants wide, like a busy Commonwealth Games at the Games six-lane motorway. These huge trails can venue in Onehunga, Auckland. Since its be seen frequently moving up trunks of arrival Argentine ant has spread to many flowering trees, where the ants feed on areas in the Auckland Region, established nectar from flowers. They are also well itself in Waikato and Tauranga and has known to exploit or ‘farm’ honeydew recently been reported from several from other insects such as scale insects, Northland sites, Gisborne, and aphids, and mealy bugs. The sheer Christchurch. numerical superiority of the species tends Argentine ants are small (2-3 mm long), to lock up these food resources and are a pale, honey-brown colour, and prevent other fauna feeding on them. cannot spread by flying, only by walking This has implications for many species or being carried. The ant is particularly of invertebrates, lizards, and birds that successful because it develops large would normally feed on nectar and multi-nest colonies with huge numbers honeydew. As well as being extremely of workers that swamp food sources. successful competitors they are predators Like most other ants they feed on nectar, of many other invertebrate groups and and similar sugary, sweet foods, as well there are even reports of them killing as protein-based foods such as insects. recently hatched chickens and invading Overseas research has shown that after broken eggs. these ants invade a site most other ant The species is also unusual in the manner species disappear and many other insect in which new nests are formed. Most groups suffer a significant decline. other ant species spread when special

RARE BITS No. 37. July 2000 21 OTHER BITS winged queens are produced. Each way in Auckland to determine if queen will leave the nest, mate then fly Argentine ant is likely to have such a to a new area and start a new nest by severe impact on our native ecosystems herself. Argentine ant nests however as has been reported overseas. One is typically feature many co-operating by Landcare Research and the second is queens and a new nest is formed when a PhD student at Auckland University. a queen takes a group of workers and While New Zealand has many exotic ant walks to a new site, a process called species these are largely confined to ‘budding off’. A single queen, by herself, urban or developed areas and have not is unable to start a new nest. Thus, if left penetrated unmodified native to themselves, Argentine ants can only ecosystems. Argentine ant may be an spread relatively slowly into new sites. exception to this rule. Results of this However, budding off allows new nests research will be some years away. to form very quickly. There can also be Unfortunately the ant has pre-empted this high densities of nests, all of which co- by invading Tiritiri Matangi Island in the operate to form huge super-colonies. Hauraki Gulf – see Conservancy News, Nests are formed between any two Auckland, in this edition of Rare Bits. surfaces close together. They prefer dry Currently Argentine ants cover just 5% sites, under cover, usually on or close to of the island, and the Auckland ground, such as under concrete or other Conservator has decided that the ant objects, in or under pot plants, or should be eradicated from Tiritiri. Thus, between any close surfaces inside for the time being, we are regarding it buildings, equipment, timber, stores etc. as an unwanted pest on islands with high Argentine ant nests could therefore conservation values. occupy places that could be uplifted and transported to new sites. Such passive ISLAND ROUNDUP movement by hitching a ride enables the from Ian McFadden species to move over great distances. To Between the Kermadecs to the north and be successful the whole nest or at least Campbell in the deep south there are a queen and a number of workers must more than 800 islands in and around be shifted. New Zealand. During the past 15 years Argentine ants can generally be we have been able to eradicate rodents recognised by their behaviour together from most of those islands (of any size) with their brownish colour. Most native which are included in the DoC estate. ants have slow moving ant trails and have The last four islands on the current list relatively small nests with low numbers are by our standards very large. Mayor of workers. Exotic ants, which may Island is scheduled for this year, with behave like Argentine ants, are generally the last three - Raoul, Little Barrier, and black. Therefore if the ant trails have large Campbell - during the next 4 to 5 years. numbers of fast moving ants that are not The recent increase in DoC funding has black then they could be Argentine ants. provided the funds to carry out all four This is particularly likely if these trails are projects. Obtaining consents and solving moving on trees. The ants themselves are any technical issues that may arise are small, but not tiny, thin and have relatively all that remains before they too become long legs and antennae compared to other rodent free. common ants. After that there are several quite large Currently there are several studies under islands in private ownership that might

RARE BITS No. 37. July 2000 22 warrant investigation. Within the DoC On the local front, the only island estate there is Auckland at around 56,000 scheduled for this year is Tuhua or ha which has pig, cats, and mice, and Mayor. The intention is to remove Antipodes at 2025 ha with mice. We then Norway rat, kiore, and feral cats. have to look into the ‘too hard’ bin where Coincidentally, Raoul has the same Great Barrier, Pitt, Chatham, and Stewart composition of pest species, so results lie. In that group are also islands like from Mayor will be directly relevant. The Resolution which caused Richard Henry basic plan for Mayor is to apply bait so much grief 100 years ago. aerially: once at 8 kg/ha by setting the Richard Henry was the person bucket at 4 kg/ha and overlapping by responsible for translocating birds in an 50% using differential GPS. The second attempt to save them from the ravages application is a back up to be flown at of introduced predators. He was right angles to the first, and will be at 4 particularly concerned about the impact kg/ha with a slight overlap. Because we of stoats on kakapo and moved hundreds want to monitor any secondary of the birds about Fiordland, releasing poisoning impact on cats a sample of 6 most of them on Resolution. However, has been radio collared. Some people his efforts were found to be in vain predict there will be very few cats killed because stoats colonised the island in by this method. This is because cats are the early 1900s, and remain there today. quite tolerant of Brodifacoum (the poison The island is about to be visited with used in the rat bait), and a cat would the purpose of evaluating our ability to need to eat about 30 dead or dying rats remove stoats. We think it is worth to acquire a lethal dose of toxin. The considering, partly because it looks like follow up for the cats will be shooting, we have been able to eradicate stoats trapping, and poisoning with 1080 fish on Chalky Island to the south. It might bait. also be a more manageable option. The Whenua Hou was checked for rats in logic here is that reinvasion will be over April. It is now two rat breeding seasons water and will not be around the entire after the island was poisoned. There have perimeter. This is because the Tasman been two reports of something rat like Sea abuts the west side. It is, therefore, being seen during the previous 6 months, quite unlike the mainland where but both incidents were subsequently reinvasion of the entire perimeter can discounted as lizards, or birds (possibly occur from adjacent areas with no fledgling blackbird). Eighteen lines of physical or geographical barrier. snap traps were set out under netting Accordingly an island like Resolution covers to prevent an inquisitive kakapo might be a better option for the from having its neck broken. This conservation dollars, and objectives. random trapping was carried out over If the project proceeds it will create the entire island and yielded no rats. Nor another category of island refuge. Unlike was there any trap interference which the remote offshore islands, which could be attributed to rodents. require little or no maintenance, Supplementary feeding of kakapo will Resolution will need regular maintenance begin in October and this will suffice as and might even need permanent staff, further indication that kiore have been but the overall effort is likely to be eradicated. Prior to this operation kiore substantially less than currently required were a nuisance about kakapo feeding for mainland islands. stations eating spilt food and constantly

RARE BITS No. 37. July 2000 23 attempting to gain access to the feed If any kiore remain on Whenua Hou we stations. There was also a disease risk expect them to appear at these sites. associated with kiore defecating in and about the feeding site.

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 11 August 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.

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