Conservation « Te Papa's Blog

Category Archives: Conservation

Critters of the Poor Knights Islands

16 February 2013 – 8.05pm

Te Papa’s curator of terrestrial vertebrates Dr Colin Miskelly recently visited the Poor Knights Islands Nature Reserve, off the Northland coast, as part of a research team tracking the at-sea movements of Buller’s shearwaters. The project is led by Graeme Taylor of the Department of Conservation, and is intended to identify the marine environments used by these elegant seabirds, both when raising young and when on migration. Here, Colin illustrates some of the large invertebrates that also occur on the islands.

The Poor Knights Islands are a treasure trove for large invertebrates, many of which have been wiped out by introduced predators on the mainland. The long isolation of the islands has also meant that some endemic species have evolved – i.e. species that only ever occurred on the Poor Knights Islands.

Flax snails were abundant under rocks and in seabird burrows, emerging on damp nights to graze on fallen leaves. It is thought that these large snails were introduced to the Poor Knights Islands from the Northland mainland by Maori.

Flax snails (Placostylus hongii), Aorangi Island, Poor Knights Islands Nature Reserve. Image: Colin Miskelly, Te Papa

Amborhytida dunniae is a medium-sized carnivorous snail that also occurs in declining numbers on the Northland mainland. We found one among leaf litter on a damp night.

Amborhytida dunniae, Aorangi Island, Poor Knights Islands Nature Reserve. Image: Colin Miskelly, Te Papa

One of the most surprising finds of the trip was a previously unknown large leaf-veined slug (family Athoracophoridae). We found four large animals (10 cm long at rest) on the sunny northern side of a towai trunk on a hot summer afternoon. They had probably been caught in the open after climbing to the canopy during rain the night before. These impressive slugs proved to be a new record for the Poor Knights Islands, and are likely to be a new species in an as-yet unnamed genus. Two other similar species occur at Waipoua/Trounson in Northland, and Hikurangi in the Bay of Plenty.

Giant leaf-veined slugs sun-bathing on a towai trunk on Aorangi Island, Poor Knights Islands Nature Reserve. This species was previously unknown to science. Image: Colin Miskelly, Te Papa

Giant centipede (Cormocephalus rubriceps). This large centipede (up to 25 cm) is widespread in the North Island and also in Australia, but reaches its largest size on rat-free offshore islands. They were mainly seen on the forest floor at night, actively hunting for large insects and lizards. A few were seen in seabird burrows in the daytime, which we tried to block out of our minds as we reached in to extract shearwater adults and chicks.

Large, fast and venomous - a very good reason to keep your tent firmly zipped closed. Giant centipede on Aorangi Island, Poor Knights Islands Nature Reserve. Image: Colin Miskelly, Te Papa

Large, fast and venomous – a very good reason to keep your tent firmly zipped closed. Giant centipede (Cormocephalus rubriceps) on Aorangi Island, Poor Knights Islands Nature Reserve. Image: Colin Miskelly, Te Papa

Poor Knights giant weta (Deinacrida fallai). Second in size only to the Little Barrier giant weta, this is one of New Zealnd’s largest insects. One female we weighed was 49 grams. They stayed well-hidden during the day, but emerged at night to browse on leaves, and many females were seen laying their eggs in the soil of the forest floor.

A female Poor Knights giant weta sits on the author’s hand. Image: Colin Miskelly, Te Papa

A female Poor Knights giant weta laying eggs on the forest floor. Note the position of her long ovipositor (egg-laying appendage) compared to the previous photograph. Image: Colin Miskelly, Te Papa

Like all insects, weta have to moult their hard exoskeleton in order to grow. The moulting female shown here was suspended upside down from a flax bush when first found. She then turned around and ate every last scrap of her old skin, recycling the precious chiton while her new skin hardened. By the morning there was nothing left of the out-sized exoskeleton, and the still pale newly-moulted female was hiding nearby.

Female Poor Knights giant weta moulting, Aorangi Island, Poor Knights Islands Nature Reserve. Image: Colin Miskelly, Te Papa

A freshly moulted Poor Knights giant weta consumes its old exoskeleton. Image: Colin Miskelly, Te Papa

Poor Knights giant jumping weta (Gymnoplectron giganteum). New Zealand’s largest jumping weta (or cave weta) is found only on the Poor Knights Islands, and has been measured at 45 cm from antenna tip to the tip of the hind leg (though the body makes up only 10% of this). We mainly saw them on damp nights, when they ran and jumped rapidly away from our lights.

Poor Knights giant jumping weta (Gymnoplectron giganteum), Aorangi Island, Poor Knights Islands Nature Reserve. Image: Colin Miskelly, Te Papa

Poor Knights ground weta (Hemiandrus sp. aff. anomalus). This yet-to-be-named endemic species emerged from its burrows in large numbers on damp nights, otherwise few were seen. With a body-length of 35 mm, and shorter appendages, it is much smaller than its more famous cousins mentioned above.

Poor Knights ground weta, Aorangi Island, Poor Knights Islands Nature Reserve. Image: Colin Miskelly, Te Papa

Clapping cicada (Amphipsalta cingulata). Common throughout the northern North Island and around Wellington, the clapping cicada spends most of its life as flightless nymphs living in the soil. The song of male clapping cicadas is one of the distinctive sounds of the New Zealand summer.

Clapping cicada (Amphipsalta cingulata) nymph, Aorangi Island, Poor Knights Islands Nature Reserve. Image: Colin Miskelly, Te Papa

Adult clapping cicada (Amphipsalta cingulata), Aorangi Island, Poor Knights Islands Nature Reserve. Image: Colin Miskelly, Te Papa

Flax weevil (Anagotus fairburni). These large flightless weevils feed only on flax (harakeke and wharariki), with the adults emerging at night to chew on the tough, fibrous leaves. Formerly found throughout New Zealand, they are now confined to rodent-free habitats, including a few mountain tops. They are most readily found on pest-free islands off northern New Zealand, in Cook Strait, and in Fiordland.

Flax weevil (Anagotus fairburni) feeding on flax/harakeke, Aorangi Island, Poor Knights Islands Nature Reserve. Image: Colin Miskelly, Te Papa

Turbott’s weevil (Anagotus turbotti). Slightly larger than its flax-eating relative, Turbott’s weevil has an even more restricted distribution – on the Poor Knights Islands, Three Kings Islands, and Muriwhenua Island in the Chickens Islands. All these islands have never had rats, whereas all the larger islands in the Hen & Chickens group had introduced Pacific rats (kiore) until they were eradicated from all but one of the islands. We saw about ten individuals, all at night, and mainly on karaka trunks. Three were seen feeding on ngaio leaves on the same bush, and one was on flax alongside its smaller cousins.

Turbott’s weevil (Anagotus turbotti) on ngaio, Aorangi Island, Poor Knights Islands Nature Reserve. Image: Colin Miskelly, Te Papa

Purple rock crab (Leptograpsus variegatus). These large crabs are widely distributed in rocky intertidal areas in northern New Zealand, but are extraordinarily abundant on the Poor Knights Islands. The full protection they receive from the combined (land-based) nature reserve and adjoining marine reserve gives a hint of the impacts human hunting pressure has had on our marine organisms elsewhere. At several points on the wave platform on Aorangi Island I was able to count over 50 purple rock crabs as they scuttled away from me. They were typically hyper-sensitive to movement, but one group were so intent on feasting on a dead shearwater that they allowed my close approach. Another was seen feeding on a dead bellbird at a brackish water hole on the edge of the forest, but it is not known whether it caught the bird or scavenged its corpse.

Purple rock crabs (Leptograpsus variegatus) scavenge the corpse of a Buller’s shearwater, Aorangi Island, Poor Knights Islands Nature Reserve. Image: Colin Miskelly, Te Papa

Acknowledgements: Thanks to Graeme Taylor of the Department of Conservation (DOC) for organising and leading the visit, and Bruce Marshall (Te Papa) and Gary Barker (Landcare Reasearch) for their thoughts on the giant slugs.

By Colin Miskelly | Also posted in Biodiversity, Bugs, insects and spiders, Crustacea, Field trips | Tagged centipede, cicada, crabs, molluscs, slug, snails, weevil, weta | Comments (4)

Reptiles of the Poor Knights Islands

16 February 2013 – 8.04pm

Te Papa’s curator of terrestrial vertebrates Dr Colin Miskelly recently visited the Poor Knights Islands Nature Reserve, off the Northland coast, as part of a research team tracking the at-sea movements of Buller’s shearwaters. The project is led by Graeme Taylor of the Department of Conservation, and is intended to identify the marine environments used by these elegant seabirds, both when raising young and when on migration. Here, Colin illustrates the nine reptile species that occur on the islands.

The Poor Knights Islands have a diverse, abundant and distinctive reptile fauna. It is diverse and abundant because the islands have never had introduced predators, other than pigs that were present on Aorangi Island until their eradication in 1936. It is distinctive as the islands are separated from the Northland coast by deep water, and so remained as isolated islands throughout periods of low sea-level during Pleistocene ice ages. This water barrier impeded lizard movements (and hence gene flow) to the extent that three Poor Knights Islands lizard species are considered to be distinct from their relatives on the mainland and nearby islands.

The Poor Knights Islands looking south, with Tawhiti Rahi in the foreground and Aorangi Island beyond. Image: Colin Miskelly, Te Papa

The top predator on the Poor Knights Islands is the tuatara, a large iguana-like reptile that is only distantly related to lizards. It lives in burrows, often in an uneasy truce with burrow-nesting seabirds. Our visit to the islands was focussed on one of the seabirds – the endemic Buller’s shearwater – and two of our study chicks were decapitated during our stay, almost certainly by tuatara.

Tuatara, Aorangi Island, Poor Knights Islands Nature Reserve. Image: Colin Miskelly, Te Papa

Tuatara (Sphenodon punctatus), Aorangi Island, Poor Knights Islands Nature Reserve. Image: Colin Miskelly, Te Papa

A decapitated Buller’s shearwater chick, Aorangi Island, Poor Knights Islands Nature Reserve. Image: Colin Miskelly, Te Papa

Tuatara are considered sit-and-wait predators, waiting motionless for lizards, large invertebrates, or hapless seabird chicks to venture within striking distance of their jaws. As a consequence, their diet is recognised as comprising ground fauna only. It never occurred to anyone that tuatara could catch and eat fully-flighted forest birds – but they can! Many young bellbirds were feeding on fallen karaka fruit around our camp. On the last day of our stay, I was alerted by alarm-calls from the bellbirds, and a commotion in the leaf litter, and was able to snap this remarkable image of a tuatara carrying a freshly killed bellbird.

A tuatara holding a freshly killed bellbird, Aorangi Island, Poor Knights Islands Nature Reserve. Image: Colin Miskelly, Te Papa

The second largest reptile on the Poor Knights Islands is Duvaucel’s gecko. Growing up to 30 cm long, these are New Zealand’s largest and heaviest lizards. Introduced predators have confined them to islands off northern New Zealand and in Cook Strait, where they emerge at night to forage on the forest floor and over rocks and tree trunks.

Duvaucel's gecko, Aorangi Island, Poor Knights Islands Nature Reserve. Image: Colin Miskelly, Te Papa

Duvaucel’s gecko (Hoplodactylus duvaucelii), Aorangi Island, Poor Knights Islands Nature Reserve. Image: Colin Miskelly, Te Papa

The most abundant lizard on the Poor Knights Islands is the much smaller Poor Knights gecko. This species has yet to be given a scientific name, having only recently been recognised as distinct from the widely-distributed Pacific gecko. Poor Knights geckos are extraordinarily variable in their colours and markings, as shown in the following image of 15 that were clustered under a coastal rock.

Poor Knights gecko (Dactylocnemis undescribed species), Aorangi Island, Poor Knights Islands Nature Reserve. Image: Colin Miskelly, Te Papa

A cluster of Poor Knights geckos, showing their variable colour and markings. Image: Colin Miskelly, Te Papa

The remaining six lizard species on the Poor Knights Islands are all skinks, only two of which were abundant and easy to find. The largest skink species there is the marbled skink, which also occurs on the Mercury and Alderman Island groups east of the Coromandel Peninsula. Marbled skinks are mainly nocturnal, hiding in seabird burrows and rock crevices during the day. However, we saw a few pregnant females basking in the sun, presumably to get extra warmth to increase the growth rate of their young.

Marbled skink, Aorangi Island, Poor Knights Islands Nature Reserve. Image: Colin Miskelly, Te Papa

Marbled skink (Oligosoma oliveri), Aorangi Island, Poor Knights Islands Nature Reserve. Image: Colin Miskelly, Te Papa

The as-yet unnamed Aorangi skink is much smaller than the marbled skink. It forages at night in leaf litter in areas with smaller rocks (and therefore smaller crevices), presumably to give protection from larger lizards and tuatara that might eat it. This skink is found only on the Poor Knights Islands, and has only recently been recognised as distinct from the ornate skink, which is found throughout the North Island.

Aorangi skink, Aorangi Island, Poor Knights Islands Nature Reserve. Image: Colin Miskelly, Te Papa

Aorangi skink (Oligosoma undescribed species), Aorangi Island, Poor Knights Islands Nature Reserve. Image: Colin Miskelly, Te Papa

Smaller still is another endemic species – Hardy’s skink, which is one of New Zealand’s smallest lizard species. We found Hardy’s skinks living among damp coastal vegetation, but they were secretive and hard to find.

Hardy's skink, Aorangi Island, Poor Knights Islands Nature Reserve. Image: Colin Miskelly, Te Papa

Hardy’s skink (Oligosoma hardyi), Aorangi Island, Poor Knights Islands Nature Reserve. Image: Colin Miskelly, Te Papa

The three remaining skink species present on the Poor Knights Islands are all widely distributed on northern offshore islands. Two of these (shore skink and moko skink) were ultra-wary, hiding among dense coastal vegetation, and scuttling away at the slightest disturbance.

Shore skink, Aorangi Island, Poor Knights Islands Nature Reserve. Image: Colin Miskelly, Te Papa

Shore skink (Oligosoma smithi), Aorangi Island, Poor Knights Islands Nature Reserve. Image: Colin Miskelly, Te Papa

Moko skink, Aorangi Island, Poor Knights Islands Nature Reserve. Image: Colin Miskelly, Te Papa

Moko skink (Oligosoma moco), Aorangi Island, Poor Knights Islands Nature Reserve. Image: Colin Miskelly, Te Papa

The ninth and final reptile species present on the Poor Knights Islands is Suter’s skink, which is New Zealand’s only egg-laying lizard. These sinuous skinks emerged at night to forage over coastal rocks, readily jumping into rock pools if disturbed. They are excellent swimmers, both on the water surface and along the bottom of pools.

Suter's skink, Aorangi Island, Poor Knights Islands Nature Reserve. Image: Colin Miskelly, Te Papa

Suter’s skink (Oligosoma suteri), Aorangi Island, Poor Knights Islands Nature Reserve. Image: Colin Miskelly, Te Papa

Acknowledgements: Thanks to Graeme Taylor of the Department of Conservation (DOC) for organising and leading the visit, and DOC Northland staff for logistic support. David Boyle assisted with finding some of the more elusive lizard species.

By Colin Miskelly | Also posted in Biodiversity, Field trips, Reptiles | Tagged gecko, lizards, skink, tuatara | Comments (6)

Birds of the Poor Knights Islands

16 February 2013 – 8.04pm

Te Papa’s curator of terrestrial vertebrates Dr Colin Miskelly recently visited the Poor Knights Islands Nature Reserve, off the Northland coast, as part of a research team tracking the at-sea movements of Buller’s shearwaters. The project is led by Graeme Taylor of the Department of Conservation, and is intended to identify the marine environments used by these elegant seabirds, both when raising young and when on migration. Buller’s shearwaters breed only on the Poor Knights Islands, and migrate to the North Pacific after breeding.

The Poor Knights Islands are one of New Zealand’s least modified island groups. They are best known as New Zealand’s premier diving location, with the waters around the islands protected as a marine reserve. Few people, however, get the opportunity to step ashore, as the islands are protected as nature reserves, with access by permit only.

The Poor Knights Islands looking north, with Aorangi Island in the foreground and Tawhiti Rahi beyond. Image: Colin Miskelly, Te Papa

One of the hardships of camping on the Poor Knights Islands – having to bathe in tidal pools. Image: Colin Miskelly, Te Papa

We visited Aorangi Island to study Buller’s shearwater (rako), a burrow-nesting seabird that breeds only on the Poor Knights Islands, but that migrates over much of the Pacific Ocean. Graeme Taylor and his co-workers had attached geolocation tags to the legs of about 30 shearwaters on previous visits, and our main task was to recapture these birds, so that the data could be downloaded from the tags to reveal where the birds had been. We also established permanent burrow plots on the island, as part of a project to estimate the size of the population.

Buller’s shearwater, Aorangi Island, Poor Knights Islands Nature Reserve. Image: Colin Miskelly, Te Papa

Our visit was timed to be a few days after peak hatching of the Buller’s shearwaters’ eggs, when we hoped that both adults would be making frequent night-time visits to feed their single chick. The chicks are covered with dense down, and are left alone in their burrows when only a few days old, while both adults return to the sea to feed.

Buller’s shearwater chick, Aorangi Island, Poor Knights Islands Nature Reserve. Image: Colin Miskelly, Te Papa

Several other seabird species also breed in burrows on the Poor Knights Islands, but most of these (including little penguin, fairy prion, fluttering shearwater, little shearwater and diving petrel) had finished rearing their young and had returned to sea. One exception was the rare Pycroft’s petrel, which we heard most nights. They also breed on a few other island groups off northern New Zealand, particularly in the Mercury Island group.

Pycroft’s petrel, Aorangi Island, Poor Knights Islands Nature Reserve. Image: Colin Miskelly, Te Papa

While Buller’s shearwaters dominated both the seabird and the nocturnal bird fauna, bellbirds (korimako) were by far the most common landbird, filling the forest with song from about 6 am each day. The bellbirds on the Poor Knights are considered a distinct subspecies from bellbirds elsewhere in New Zealand, differing slightly in colouration and measurements. Bellbirds are so abundant on the Poor Knights Islands that they exclude most other forest birds. We saw only a single fantail, and no tui, silvereyes, grey warblers or tomtits. It is likely that the bellbirds also prevent moreporks from establishing, as bellbirds mob moreporks, and there would be nowhere on the island for the owls to hide in the daytime.

Male bellbird, Aorangi Island, Poor Knights Islands Nature Reserve. Image: Colin Miskelly, Te Papa

Female bellbird, Aorangi Island, Poor Knights Islands Nature Reserve. Image: Colin Miskelly, Te Papa

After bellbirds, the most abundant landbirds on the island were red-crowned parakeets (kakariki), plus there were a few New Zealand pigeons (kukupa / kereru) feeding on ripe karaka fruit, and kingfishers (kotare) feeding on lizards, insects and crabs. Perhaps the most interesting of the landbirds was the secretive spotless crake (puweto). These small rails live in dense wetlands on the mainland, and so are rarely seen. In the absence of predators they venture into more open habitats, occurring under open forest on the Poor Knights Islands.

Adult spotless crake, Aorangi Island, Poor Knights Islands Nature Reserve. Image: Colin Miskelly, Te Papa

Juvenile spotless crake, Aorangi Island, Poor Knights Islands Nature Reserve. Image: Colin Miskelly, Te Papa

By Colin Miskelly | Also posted in Biodiversity, Birds, Field trips | Tagged bellbird, Buller's shearwater, Pycroft's petrel, spotless crake | Comments (7)

Life through a burrowscope lens (Part 2) – subterranean Poor Knights Islands

16 February 2013 – 8.03pm

Te Papa’s curator of terrestrial vertebrates Dr Colin Miskelly recently visited the Poor Knights Islands Nature Reserve, off the Northland coast, as part of a research team tracking the at-sea movements of Buller’s shearwaters. The project is led by Graeme Taylor of the Department of Conservation, and is intended to identify the marine environments used by these elegant seabirds, both when raising young and when on migration. Buller’s shearwaters breed only on the Poor Knights Islands, and migrate to the North Pacific after breeding. They breed in rock crevices or in burrows that they excavate in soil. Here, Colin describes some of the wildlife they share their subterranean homes with.

An adult Buller’s shearwater on Aorangi Island, Poor Knights Islands Nature Reserve. Image: Colin Miskelly, Te Papa

A burrowscope is a field-hardened endoscope on steroids, used to view the interior of burrows. It can be used to determine whether a burrow is occupied or vacant, to identify what species is in a burrow, and to provide information on breeding success. At least seven species of seabirds excavate or breed in burrows and rock crevices on the Poor Knights Islands, and many other animals also inhabit the thousands of burrows there.

Buller’s shearwater burrows on Oneho hill, Aorangi Island, Poor Knights Islands Nature Reserve. Image: Colin Miskelly, Te Papa

The following images show some of the secrets of underground life on this pest-free nature reserve. During our visit (late January to early February), most of the breeding seabird species had finished breeding, but the Buller’s shearwaters had recently hatched their eggs.

An adult Buller’s shearwater inside its burrow, viewed through a burrowscope. Image: Colin Miskelly, Te Papa

Buller’s shearwater egg viewed through a burrowscope. Image: Colin Miskelly, Te Papa

Buller’s shearwater chick inside its burrow, viewed through a burrowscope. Image: Colin Miskelly, Te Papa

Several species of reptiles live in burrows on the Poor Knights Islands, including tuatara, which occasionally kill and eat shearwater chicks. The smaller skinks and geckos usually move rapidly away from the light cast by the burrowscope, and rarely pose long enough for a photograph to be taken.

Tuatara inside a shearwater burrow on Aorangi Island, as viewed through a burrowscope. Image: Colin Miskelly, Te Papa

A marbled skink (the dark shape on the right) inside a shearwater burrow on Aorangi Island, as viewed through a burrowscope. Image: Colin Miskelly, Te Papa

Duvaucel’s gecko inside a shearwater burrow on Aorangi Island, as viewed through a burrowscope. Image: Colin Miskelly, Te Papa

Flax snails hide in seabird burrows and under rocks during the day, emerging on damp nights to graze on fallen leaves.

Flax snail (Placostylus hongii) inside a shearwater burrow on Aorangi Island, as viewed through a burrowscope. Image: Colin Miskelly, Te Papa

In addition to many seabird species, some landbirds also nest in burrows. We found a kingfisher nest in a low bank, with the entrance only 20 cm above the forest floor. The two large chicks inside froze statue-like when the burrowscope was inserted into their hole.

Kingfisher burrow entrance, Aorangi Island, Poor Knights Islands Nature Reserve. Image: Colin Miskelly, Te Papa

Two fully-grown kingfisher chicks inside their burrow on Aorangi Island, viewed through a burrowscope. Image: Colin Miskelly, Te Papa

By Colin Miskelly | Also posted in Biodiversity, Birds, Bugs, insects and spiders, Field trips, Reptiles | Tagged Buller's shearwater, burrowscope, gecko, kingfisher, lizards, skink, snails, tuatara | Comments (4)

Critters of Titi Island Nature Reserve, Marlborough Sounds

16 January 2013 – 4.28pm

Titi Island is a 32-ha reserve administered by the Department of Conservation and situated in the outer Marlborough Sounds. The island’s fauna was impacted by introduced Norway rats until these were eradicated in the early 1970s. The island has since been free of all introduced predators. Two species of large flightless insects plus tuatara were introduced to the island between 1995 & 2001 (see below). Te Papa researchers visited the island in January 2013 to attach tracking devices to breeding flesh-footed shearwaters, and to estimate the breeding population of these threatened birds. Our 3-day visit also provided an opportunity to encounter some of the island’s more cryptic wildlife.

The most well-known of Titi Island’s inhabitants are the tuatara introduced from North Brother Island and from captivity in 1995. At the time, tuatara from the Brothers Islands were considered to be a separate species from other tuatara. More recent genetic research has resulted in all tuatara being lumped back together as a single variable species. We encountered several tuatara inside shearwater burrows that we checked with a burrowscope.

Tuatara (Sphenodon punctatus) on Titi Island. Image: Colin Miskelly, Te Papa

Three lizard species are known from Titi Island. We found all three species to be present, but were surprised how few individuals we found. Rodent-free islands typically have abundant lizard populations.

Spotted skink (Oligosoma lineoocellatum) among iceplant on Titi Island. Image: Colin Miskelly, Te Papa

The two spotted skinks seen were among low coastal vegetation, as was the single common gecko found. Spotted skinks occur from Hawke’s Bay south to South Canterbury, but are most abundant on islands in the Marlborough Sounds and Wellington Harbour. They are a sun-loving species, and are most often noticed as they move back under cover when they detect someone approaching. Common geckos occur from Northland to Marlborough and Nelson, and are extremely abundant on many islands in the Marlborough Sounds and around Wellington. They are nocturnal, hiding during the day and emerging to forage at night.

Common gecko (Woodworthia maculata) on dead coastal flax/wharariki on Titi Island. Image: Colin Miskelly, Te Papa

The single brown skink seen was among a rock outcrop under forest. This species occurs from Taranaki south to north Westland, again being most abundant on rodent-free islands. It does not require as much access to sunlight as the larger spotted skink, and can be found under open forest as well as among grass and shrubland.

Brown skink (Oligosoma zelandicum) on Titi Island. Image: Colin Miskelly, Te Papa

Weevils are a group of beetles with a bad name, as some species are major pests of crops and stored food products. But they are an extraordinarily diverse group, with the weevil family containing more species than any other family of organisms on the planet. New Zealand has several large flightless weevil species that are mainly or entirely confined to sites that lack introduced rodents. These include the flax weevils introduced to Titi Island from nearby Maud Island in 2001. We found their characteristic feeding sign on flax plants all over the island, but the 2 cm-long animals were only visible at night when they emerged to feed.

Flax weevil (Anagotus fairburni) and its characteristic ragged feeding sign on a coastal flax/wharariki leaf on Titi Island. Image: Colin Miskelly, Te Papa

The most frequently encountered large beetle on Titi Island was a species of darkling beetle (genus Mimopeus). These also emerged at night, but were often found under rocks and in bird burrows during the day, and their larvae were common in the soil. Darkling beetles are a staple diet item for tuatara on many islands, though tuatara are partial to weta when they can catch them.

Darkling beetle (Mimopeus sp.) on a tree trunk on Titi Island. Image: Colin Miskelly, Te Papa

We failed to find any sign of the Cook Strait giant weta introduced to Titi Island from Maud Island in 2001, but did not have an opportunity to search the right habitats at night. The similarly-sized Wellington tree weta were very common, emerging at night and mainly staying in the trees out of reach of hungry tuatara.

Female Wellington tree weta (Hemideina crassidens) on Titi Island. Image: Colin Miskelly, Te Papa

We had been warned of tent-eating ground weta before our arrival. These voracious little (2.5 cm-long) weta live in tunnels in the soil and emerge at night to find other insects to eat. If anything is placed over their tunnel entrances, they simply chew through it. Rather than having our tent groundsheets wrecked, we devised the cunning plan of placing snow-foam bedrolls under the groundsheets. This was to little avail – the ground weta still chewed through them!

Ground weta (Hemiandrus sp.) on Titi Island. Image: Colin Miskelly, Te Papa

Sarah Jamieson eyeballing one of several holes chewed through her bedroll by ground weta on Titi Island. Image: Colin Miskelly, Te Papa

We also found several shells and one live animal of the medium-sized native landsnail Rhytida stephenensis. This carnivorous snail grows up to 34 mm across and is found on islands in the Marlborough Sounds and south to Kaikoura, with subfossil records from Takaka Hill.

The carnivorous snail Rhytida stephenensis on Titi Island. Image: Colin Miskelly, Te Papa

By Colin Miskelly | Also posted in Biodiversity, Bugs, insects and spiders, Field trips, Reptiles | Tagged gecko, lizards, skink, snail, tuatara, weevil, weta | Comments (3)

Life through a burrowscope lens – subterranean Titi Island

16 January 2013 – 4.27pm

By Sarah Jamieson & Colin Miskelly

Over the past two (southern hemisphere) summers, Te Papa seabird researchers have been investigating population trends and foraging behaviour of flesh-footed shearwaters. These all-dark seabirds are well known to recreational fishers around the North Island and in Cook Strait, as the birds have the annoying habit of sitting behind boats and diving after bait. This behaviour puts the birds at risk of being hooked and drowning on both commercial and recreational fishing lines. There is also evidence that some birds are deliberately killed by fishers, presumably after they become angry with the birds interfering with fishing. Added to this is the alarming revelation that some New Zealand flesh-footed shearwaters tracked on migration were found to have foraged within a few kilometres of the damaged Fukushima Daiichi nuclear power plant on the east coast of Japan. All this means bad news for flesh-footed shearwaters, which appear to be declining throughout their range.

Flesh-footed shearwater extracted from its burrow in order to be fitted with a tracking device. Image: Colin Miskelly, Te Papa

Our study has two main parts – estimating numbers on land, and tracking where the birds go at sea. Flesh-footed shearwaters nest in deep burrows that they excavate in soft soil, and both parts of the study require a means to see what is under the ground. Other animals also live underground on the islands where flesh-footed shearwaters nest, and so estimating numbers requires both counts (or estimates) of the number of burrows, and measurements of occupancy rates, i.e. what percentage of burrows is occupied by flesh-footed shearwaters. In addition, to track the birds at sea, we need to not only attach tracking devices to the birds, but to re-catch the same birds some weeks later to remove the device and down-load the data. This requires selecting birds that are incubating eggs, and will have a high motivation to return to the same site after having a tracking device taped to their back feathers.

A burrow on Titi Island – but what lies within? Image: Colin Miskelly, Te Papa

In order to see what species is in a burrow, and whether it is sitting on an egg, we use a device called a burrowscope. This is similar in principle to a surgeon’s endoscope, though of rather more robust design to cope with use in the field. A small camera lens surrounded by a cluster of lights is mounted on the end of a long flexible tube, which is carefully inserted into the burrow. An image from the camera is transmitted to a small video monitor screen, which allows the researcher to see what is in the burrow.

Te Papa researcher Dr Sarah Jamieson using a burrowscope on Titi Island. Image: Colin Miskelly, Te Papa

Flesh-footed shearwater egg inside a burrow on Titi Island, as seen on the burrowscope monitor. Image: Colin Miskelly, Te Papa

On Titi Island in the outer Marlborough Sounds we found three bird species and one large reptile species living in the burrows. The accompanying images show some of the views we had on the burrowscope screen. Our target species (flesh-footed shearwater) looks very similar to its cousin the sooty shearwater, which also nests on Titi Island. The main distinguishing character through the burrowscope is whether the bird has a slender dark bill (sooty shearwater) or a large pale bill with a dark tip (flesh-footed shearwater).

Flesh-footed shearwater inside a burrow on Titi Island. Image: Colin Miskelly, Te Papa

Sooty shearwater inside a burrow on Titi Island. Image: Colin Miskelly, Te Papa

Several burrows were found to contain little penguins, which had climbed up the steep slopes from the rocky shore below. These birds had finished breeding for the year, and had returned to shore for their annual moult. The presence of a moulting penguin in a burrow was usually evident from shed feathers at the burrow entrance even before the burrowscope was inserted.

Little penguin inside a burrow on Titi Island. Image: Colin Miskelly, Te Papa

The rarest of the burrow inhabitants was the tuatara – an iguana-like reptile unique to New Zealand, and with no close living relatives anywhere else on earth. Tuatara mainly eat large insects and also lizards, but occasionally take small seabirds and their chicks. They seemed to have an uneasy truce with the two large shearwater species, and we found some burrows occupied by both a tuatara and a shearwater.

Tuatara inside a burrow on Titi Island. Image: Colin Miskelly, Te Papa

Information on the Sextant Technology Ltd ‘Taupe’ burrowscope used

By Colin Miskelly | Also posted in Biodiversity, Birds, Field trips, Penguins, Reptiles | Tagged flesh-footed shearwater, little penguin, sooty shearwaters, tuatara | Comments (5)

Green Island (Papatea) – 1941 and 2012 – In the footsteps of Edgar Stead (Part 8)

8 January 2013 – 11.19am

Te Papa’s curator of terrestrial vertebrates Dr Colin Miskelly is researching the life and work of the Canterbury naturalist Edgar Stead (1881-1949). This includes re-taking Stead’s photos from the same photo-point, taking other images to illustrate his diaries, and describing how the ecology and wildlife of each of 10 islands has changed since Stead’s visits.

Of all the islands that Edgar Stead visited, and for which his diaries exist, Green Island in eastern Foveaux Strait is the least well known. Green Island lies to the east of Ruapuke Island, and should not be confused with the much smaller homonymous Green Island near Dunedin. All the Ruapuke Island group are privately owned, mainly by descendants of the Kai Tahu chief Tuhawaiki. Some of the owners have huts on Green Island and harvest muttonbirds / titi (chicks of the sooty shearwater) each year. We were privileged to be granted access to the island, and were accompanied by two of the island’s owners during our 10 hours ashore.

Green Island from the south-west. Image: Colin Miskelly

It is not clear what motivated Stead to visit Green Island, other than the hope of finding rare birds on a ‘new’ island. He and his companions (Robert Wilson and Percy Elworthy) discovered that the island was free of introduced predators apart from weka, and this remains the case today. Birdlife was and is abundant, but there have been some notable changes over the ensuing 71 years.

Muttonbirding hut in Ruapuke Island, with Ruapuke Island in the background. Upper image taken by Edgar Stead in 1941 (courtesy of Canterbury Museum 2001_59_319); lower image by Colin Miskelly

Muttonbirding hut on Green Island, with Ruapuke Island in the background. Upper image taken by Edgar Stead in 1941 (courtesy of Canterbury Museum 2001_59_319); lower image by Colin Miskelly

Stead and Wilson estimated there to be 1.5 million pairs of fairy prions / titiwainui and broad-billed prions / parara breeding on the island in 1941, but we saw little evidence of them in 2012. They are both still present, but clearly in much reduced numbers. It is not clear why the population has crashed, as the weka population does not appear large enough to have caused such a massive decline. Perhaps the decline has been driven by at-sea conditions, rather than by conditions on the island.

Dark morph weka on Green Island, December 2012. Image: Colin Miskelly

Another species that has declined or disappeared on the island since 1941 is the southern skua, which should be the top predator on the island. About 10 pairs were present and breeding in 1941, but we saw none and found none of their distinctive middens of seabird remains.

Flowering southern rata and Stewart Island tree-groundsel (Brachyglottis stewartiae) on Green Island, December 2012. Images: Colin Miskelly

The landbirds on the island were much as Stead found them, with the brown creeper the most abundant species, and bellbird, tomtit and robin all being common. We also found tui to be numerous, probably attracted by the spectacular flowering of southern rata.

Brown creeper on Green Island, December 2012. Image: Colin Miskelly

We recorded over 20 New Zealand pigeons / kereru – a species not recorded by Stead. They are strong flyers and could easily cross the 2 km from Ruapuke Island. More surprising was that we found fernbirds to be common, when Stead specifically noted their absence. In 1941, fernbirds were found only on Bird island 3 km west of Ruapuke Island. Usually considered poor flyers and unlikely to cross water gaps, these furtive birds have apparently colonised both Ruapuke and Green Islands since Stead’s visit.

Fernbird photographed on Ruapuke Island, December 2012. Image: Colin Miskelly

One feature of the island that has not changed since Stead’s time was the abundance of geckos around the dwellings. We also saw several common skinks, but failed to find the green geckos reported from the island.

Geckos (Woodworthia ‘Otago large’) on Green Island, December 2012. Image: Colin Miskelly

The only seal species that Stead and his companions noted in 1941 was a single male sea lion. We did not see any sea lions, but there are now several hundred fur seals breeding on the island.

New Zealand fur seal cows and pups on Green Island, December 2012. Image: Colin Miskelly

By Colin Miskelly | Also posted in Biodiversity, Birds, Field trips, Mammals, Reptiles | Tagged brown creeper, edgar stead, fernbird, fur seal, weka | Comments (8)

Getting into our uniforms: A behind the scenes look

18 October 2012 – 9.13am

Hopefully many of you have seen or plan to see our newest Eyelights gallery exhibition that opened on the 24^th of September. Uniformity: Cracking the Dress Code features uniforms worn in various contexts—school, church, battlefield, rugby field, and even those worn on the street. A previous post about Uniformity talked about the role that outside organisations had in ensuring that the uniforms on display were presented correctly. In this exhibition we worked with not just the New Zealand Special Air Service Defense Group (SAS) , but the office of the Governor General and a private firearms collector; we also had a staff member who had worn one of the school uniforms on display. Curators worked to find archival images, such as one of Adele Howlson, Wellington Technical College student, to make sure that our approach to display of the garments was as informed as possible. As the conservator assigned to the exhibition, I was responsible for translating these images (and video footage) into a correct and effective final “look”. So once we had a good idea of what a uniform should look like on display, what was done to achieve that?

A highlight of the Uniformity exhibition is Corporal Willie Apiata, VC’s combat uniform from Afghanistan. Corporal Apiata became the first recipient of the Victoria Cross for New Zealand in 2007. The Victoria Cross is the highest military award for an act of bravery, and Corporal Apiata received it for his actions in Afghanistan in 2004, in which he carried a wounded soldier across a battlefield, under fire, to safety. For the display of Corporal Willie Apiata, VC’s uniform, the choice of a full body fibreglass fashion mannequin (rather than a dressmaker’s dummy) was dictated primarily by the existence of several components like shemagh (headscarf), boots, gloves, and weaponry, that all called for a sturdy and lifelike display form with hands, feet and head. However, a great deal of modification of the form was required. When Corporal Apiata consulted with us about the display, we talked with him about various details like what he would have carried in his pockets, how he would have rolled his sleeves, worn his hunting knife and the firearms. Corporal Apiata also showed us how to tie the headscarf. At the end of our meeting, I measured across Corporal Apiata’s back, and found that the mannequin was 10 cm narrower from shoulder to shoulder than Corporal Apiata.

Uniform of Colonel Willie Apiata, VC dressed on its mannequin without any modifications. The mannequin was about 10 cm narrower between the shoulders than Colonel Apiata, and slightly taller than him. Image copyright Te Papa.

Uniform of Corporal Willie Apiata, VC dressed on its mannequin without any modifications. The mannequin was about 10 cm narrower between the shoulders than Corporal Apiata, and slightly taller than him. Image copyright Te Papa.

Based on that consultation and further collaboration with the SAS, the display mannequin was modified to achieve a more correct presentation. Dacron polyester wadding was layered between two undershirts on top and between black tights and thermal underwear on the bottom of the mannequin, using anatomical drawings of muscles to shape and position the Dacron. The mannequin had to then be adapted to fit Corporal Apiata’s gloves, which could not be put on to the hands of the form because its fingers were fused. Object Support Mountmaker Penny Angrick cut the fingers off the fibreglass form and constructed new ones using armature wire, foam and cotton gloves.

Mannequin hands with rebuilt fingers constructed of armature wire and archival foam. Image copyright Te Papa.

The new hands not only enable the gloves to be displayed on the mannequin, but they also enable the fingers to be articulated into more lifelike positions, making the display a little more dynamic.

Detail of the glove after the modification of the display mannequin. Image copyright Te Papa.

Finally, the mannequin required modifications to accomodate mounts for the M4 rifle and replica P226 pistol. Because of the weight of the firearms, and security concerns (even though neither is a functional weapon), these were to be displayed on the body form supported and secured in place with locking mounts. These mounts consisted of welded metal parts attached to the mannequin itself. So Penny made large cavities in the mannequin to accomodate them, as well as making the mounts themselves (she also had to get a firearms license).

The display mannequin with a cavity cut out, to accomodate the required locking mounts for the firearms and to enable the mannequin to be screwed to the back wall of the case. Image copyright Te Papa.

There was actually very little conservation that was done on Corporal Apiata’s uniform. The shirt has a large hole in it at the front, but it was decided to treat that as historically important evidence of the battlefield conditions, and I did not patch or stabilise the hole. Many other aspects of the uniform’s condition, such as creases and thinning fabric and the knees, were similarly handled with care but not treated, for the same reason.

Desert Disruptive Pattern Material uniform, early 2000s, New Zealand. New Zealand Defence Force, Whitehead Productions. Gift of Corporal B.H. Apiata, VC, 2012. Te Papa

The uniform dressed on the modified mannequin. Desert Disruptive Pattern Material uniform, early 2000s, New Zealand. New Zealand Defence Force, Whitehead Productions. Gift of Corporal B.H. Apiata, VC, 2012. Te Papa

By peranne | Also posted in Exhibitions, History, Textiles | Tagged Corporal Willie Apiata, Uniformity: Cracking the Dress Code | Comments (3)

Behind the Scenes of Angels and Aristocrats

8 October 2012 – 5.06pm

Te Papa’s latest art exhibition, Angels & Aristocrats, opens on the 20^th October in the Level 5 galleries. The exhibition draws on a number of collections from around New Zealand including artworks from Te Papa’s collection which you will see on display. Some of these paintings required attention in the conservation lab before the exhibition began, to allow them to be fully appreciated on display. As paintings age they begin to deteriorate and changes occur in their appearance and condition. Both deterioration and change are a result of the interaction of all the materials which make up a painting and the environment around them. Therefore, as conservators we sometimes have to intervene and carry out treatment to repair and stabilise the art work.

Mrs Humphrey Devereux; 1771; Copley, John Singleton. Ultra-violet examination of the painting during cleaning. The varnish fluoresces a bright blue colour which indicates a synthetic varnish layer. The painting is partially cleaned at this point hence the patchy nature of the fluorescence. You can also clearly see the test cleaning spots and two areas of damage which appear as white marks in the image, 2012, Photograph by Katherine Campbell. © Te Papa

Conservation procedures aimed at preventing or slowing deterioration include repair of tears, correction of canvas distortions and consolidation of flaking paint. Restorations may also be performed when the aesthetic appearance of the painting and the intention of the artist have been compromised, and can include the removal of discoloured surface coatings and the filling and retouching of loss.

The rectangular shape on the subject’s face is a cleaning test which reveals the original colour of the composition beneath, 2012, Photograph by Katherine Campbell. © Te Papa

One of the paintings that underwent conservation before the exhibition was Mrs Humphrey Devereux painted by John Singleton Copley in 1771. The varnish layer on this portrait, applied in the 1960’s during a previous conservation treatment, had diminished the tonal ranges of the work as it became very degraded and matte over time, therefore requiring removal. The varnish removed from the portrait was very dark yellow and quite thick and it took several weeks to complete the removal using a solvent mixture arrived at through a testing regime to ensure its effectiveness without any damage to the underlying paint.

Removal of the old varnish had a dramatic effect on the overall colour, balance and depth of the painting, 2012, Photograph by Katherine Campbell. © Te Papa

The painting was re-varnished with a clear, synthetic resin to emulate the original surface. The varnish selected is one that has been developed specifically for the conservation profession and is known to be stable and reversible which ensures that any future cleaning will not need to be repeated for a long time and if it does eventually become necessary, it can be done with the least possible intervention. The final part of the treatment was to carry out inpainting or retouching over the areas of old damage and then a final layer of varnish was sprayed onto the painting before it was refitted into its frame.

By Katherine Campbell | Also posted in Art, History | Tagged Art, collections, conservation, Exhibitions | Comments (1)

Xray Vision, part I

11 July 2012 – 4.36pm

As an art conservation student, I was frequently encouraged by my tutors to think of my profession as a three-legged stool—a platform supported by the three disciplines of connoisseurship, fine arts, and science. Understanding the science of how materials age is critical for being able to slow down deterioration. In addition, scientific methods of analysis can inform our understanding of how an object was made, when it was made, or where it came from. For me, this kind of investigation is one of the most fun and interesting parts of my job. This past week I used Xray energy, produced by two different pieces of equipment in different ways, to find out more about objects in Te Papa’s collection. This post describes the use of a non-invasive scanner to study a taiaha (long club fighting staff). In a subsequent post I will talk about a new piece of equipment in our lab called XRF.

Taiaha (long club fighting staff), 1800, Taranaki. Maker unknown. Purchased 1905. Te Papa

The taiaha was purchased by the museum in 1905, and is thought to be about 200 years old. It has a decorative band (tauri) of red wool textile stitched at the top, but it’s evident from the shape and bulk of the tauri that the wool is covering other soft material. When I first examined the taiaha, I was intrigued. Other textile wrappings that I’ve seen on taiaha aren’t stitched, they’re wrapped, and examples with dog hair tassels often have feather adornment as well. Was the wool covering feathers, or many layers of other wrappings? Proceeding with the assumption that the red wool was an historically important part of the object and not a restoration treatment, I did not strip it off to satisfy my curiosity! Instead, I investigated the possibility of having the object Xrayed. Te Papa does not (yet!) have digital Xray capability, and tikanga (cultural protocol) considerations ruled out Wellington Hospital. So, it was off to the National Isotope Laboratory at GNS, in Lower Hutt.

Te Papa’s Kaitiaki Taonga Māori Shane James and Objects Conservator Nirmala Balram working with Karyne Rogers and John West at the GNS Isotope Centre. Image by Anne Peranteau, copyright Te Papa.

At GNS, we worked with Karyne Rogers and John West to obtain an Xray image of the taiaha using a non-invasive Xray scanner, of the type that is commonly used in airports. The scanner provides an image that indicates the relative density of the materials being scanned—orange for low density organic material, green for medium density material, and blue for high density material. Have you ever wondered what the airport security personnel see on their screen when your bag goes on the belt? This gives you some idea.

Image of taiaha ME001310 produced by non-invasive Xray scanner. The arrows indicate the wrappings beneath the red wool. Image by Anne Peranteau. Copyright Te Papa.

From the image we were able to conclude that the material below the red wool is a higher density material, applied in two wide bands. Raupo or muka were two possibilities put forward by Objects Conservator Nirmala Balram and Kaitiaki Taonga Māori Shane James. The wrappings below the red wool are not woven cloth, nor are feathers present.

The taiaha will be included in an upcoming Te Papa exhibition called Uniformity: Cracking the Dress Code, scheduled to open in September. Shane will be working with GNS to do more scanning of putorino (flutes) and other musical instruments, to learn more about the construction of these objects, and particularly their interior dimensions in relationship to the sounds they make.

By peranne | Also posted in Māori | Tagged GNS Science, materials, scanner, taiaha, textile, Uniformity: Cracking the Dress Code, wrappings, xray | Comments (0)

Te Papa's Blog

Category Archives: Conservation

Critters of the Poor Knights Islands

Reptiles of the Poor Knights Islands

Birds of the Poor Knights Islands

Life through a burrowscope lens (Part 2) – subterranean Poor Knights Islands

Critters of Titi Island Nature Reserve, Marlborough Sounds

Life through a burrowscope lens – subterranean Titi Island

Green Island (Papatea) – 1941 and 2012 – In the footsteps of Edgar Stead (Part 8)

Getting into our uniforms: A behind the scenes look

Behind the Scenes of Angels and Aristocrats

Xray Vision, part I

Pages

Recent posts

Categories

Search blog

Join the discussion

Follow us by email

Other blogs

Use of images

Te Papa Links

Te Papa Home - Fingerprint

Te Papa Homepage - Text

What's on

Plan your visit

Education

Collections

Shop

Venues

Follow “Te Papa's Blog”