Was the kawekaweau the world's largest gecko?

Forest and Bird, Volume 23, Issue 2, 1 May 1992, Page 44

Was the kawekaweau the world's largest gecko?

TONY

WHITAKER

A unique specimen of a gecko, discovered languishing in the basement of a French museum, may be the only tangible evidence of the large forest lizard called kawekaweau

in Maori folklore.

looks at what is

known of the kawekaweau and recent efforts to confirm that the specimen of Hoplodactylus delcourti, the world’s largest gecko, came from New Zealand.

HEN PAKEHA arrived in New Zealand Maori told them of large lizards — known as kawekaweau (sometimes kaweau or koeau) — which inhabited the dense forests of the North Island. Kawekaweau were usually described as about 60 cm long and arboreal, and were distinguished from a similar-sized reptile, the tuatara. Some accounts describe them as grounddwelling or amphibious, and it was even suggested they could fly. They reputedly ate the berries of forest trees such as tawa. Although some early pakeha settlers © are believed to have seen kawekaweau, there are no known specimens or precise descriptions. In fact, the best account, from 1870, was also the last. Gilbert Mair described how a Urewera chief had killed a kawekaweau found beneath the bark of

a rata tree in the Waimana Valley, near Whakatane. This animal was said to be "about two feet [60 cm] long, and as thick as a man’s wrist; colour brown, striped longitudinally with dull red". By the middle of this century the absence of any further sightings, and the complete lack of material to support the existence of a lizard of half a metre or longer, meant the biological reality of the kawekaweau was in doubt. It seemed that either the animal was mythical, like the taniwha and kumi, or perhaps based on grossly exaggerated accounts of a much smaller species of lizard. Then in 1979 Alain Delcourt, curator at the Museum d’Histoire Naturelle de Marseille in France, found a study skin of a huge gecko among a collection of mounted reptiles stored in the museum’s basement. Unfortunately, there was no information with the specimen or in the museum registers of where, when or by

whom it had been collected. And although it had been in the museum since at least 1902 there was no indication of when it arrived. Realising immediately the significance of his find — at 62 cm it was half as long again as the previously largest known gecko, Rhacodactylus leachianus of New Caledonia — Delcourt sent photographs of the specimen to various herpetologists hoping for identification. Finally Aaron Bauer and Tony Russell in the United States, specialists in gecko taxonomy, concluded from the external form and X-rays of its skeleton that the large gecko at Marseille was probably a species of Hoplodactylus, a genus until then found only in New Zealand. In 1986 Bauer and Russell formally named the Marseille gecko Hoplodactylus delcourti, honouring Alain Delcourt. Since then, H. delcourti has generally been regarded as part of the New Zealand fauna and has been closely linked with the kawekaweau of Maori folklore. However, doubts and questions remain about its genealogy and about how and when it got to Marseille. PROM THE BEGINNING of the «4 colonial period Marseille was the __ French base for many voyages to +. — this part of the world and most material returning from here would have passed through that port. The huge gecko may have been obtained by the museum between 1833 and 1869, a period for which all museum records have been lost, or it may have formed part of the founding collection when the museum was established in 1819. Another possibility is that it was acquired by the original director, during a visit to India and the Far East in 1819. An argument often used by those sceptical of the close link between the Marseille gecko and the kawekaweau, is the apparent absence of skeletal material of a large gecko amongst the relatively well documented sub-fossil faunal remains from New Zealand caves and dunes. Bones of tuatara and many of the larger species of lizards now extinct on the mainland occur at widely distributed sites, yet bones large enough to be from H. delcourti had never been recognised. However, two bones collected in central Otago in the 1870s could be from a gecko of this dimension. One was a reptile jaw bone, similar in size to that from a large tuatara (60 cm) but, instead of being serrations of the jaw itself, the teeth were separate as in lizards. The other was a small curved bone believed at the time to be the rib of a kumi — a large reptile in Maori folklore. The jaw bone

can no longer be found but the "rib" is still in the Canterbury Museum. Reassessment of this "rib" indicates it is probably a cloacal bone — paired bones occurring in the genitalia of male geckos — which its length (14 mm) suggests came from a gecko about 60 cm long. S PART OF the sesquicentennial celebrations in 1990 the National . Museum of New Zealand mounted a special exhibition, The Foipotien Fauna, focussing on the. remarkable New Zealand herpetofauna. After protracted negotiations with the Museum d’Histoire Naturelle de Marseille and the French government, approval was gained to bring Hoplodactylus delcourti to New Zealand as the exhibition’s centrepiece. The specimen was on display for two months before a multi-disciplinary research effort was mounted to try and work out its age and origin. This research had the makings of a real detective story. The specimen of H. delcourti is what zoologists call a "study skin". Rather than being preserved as a pickled specimen the animal has been stuffed, but instead of being mounted in a natural posture it 1s out straight and with its limbs extended. X-rays of the specimen show the skull is

intact and the limbs are present but the vertebral column and ribs are gone. The skin has been tanned and it has had artificial eyes fitted. Researchers were not allowed to open the specimen so they had to be content with what could be gleaned from the outside or from X-rays. First to check out the specimen were National Museum taxidermist Noel Hyde, and Rose Evans and Valerie Carson of the museum’s Conservation Unit. In their opinion the animal had clearly been prepared by a trained taxidermist. From his knowledge of the history of taxidermy Noel believes the mount was prepared early in the 19th century. Earlier taxidermy techniques on small animals involved leaving their skeletons more or less intact to frame up the mount. Later techniques used elaborate wire or wood frameworks for the same purpose (X-rays show there is no wire or wood in this specimen), and usually involved the removal of most of the skull and all limb bones except for the toes. The artificial eyes lack the detail of the realistic glass eyes that became common-place in taxidermy by the middle of last century. The thread is 2-ply linen that would have been widely available through the 19th century.

*KAWEKAWEAU*

The material used to stuff zoological specimens can often indicate their origin. This was examined in the hope that the big gecko might contain plant fibre peculiar to New Zealand such as flax. Instead, the stuffing almost certainly contains sisal, a fibre commonly used in taxidermy last century. An expert on the New Zealand geckos, Rod Hitchmough at Victoria

University, re-assessed the external form of the gecko, counting and measuring scales and checking body proportions. He confirmed Bauer and Russell’s placement of the big gecko in Hoplodactylus. X-rays of the specimen were able to provide sufficient detail of the skull and limb bones to also show that its placement in Hoplodactylus is probably correct on the basis of its bone structure. The H. delcourti specimen is a male and fortunately one of its cloacal bones is still in position, adhering to the inside of the skin at the base of the tail. The X-ray images are remarkably similar in shape to the kumi "rib" in Canterbury Museum and it is virtually identical in size. Next came Victoria University parasitologist Ruth Ainsworth who thoroughly examined the whole exterior surface of the H. delcourti specimen in the hope of finding New Zealand parasitic mites still adhering to it. Unfortunately this was not to be. After the parasitologist came the geneticist. Laboratory techniques with DNA now allow genetic "finger-print-ing" to identify the relationships between species or even between individuals. Geoff Chambers, from Victoria University, hoped that minute tissue samples scraped from the inside surface of the skin would show how H. delcourti is related to other geckos and prove it is correctly placed in the New Zealand genus Hoplodactylus. Sadly however, the samples yielded no DNA, perhaps because of the tanning process used on the skin. The final effort to prove a New Zealand origin for H. delcourti involved DSIR/’s forensic palynologist (a person

who studies plant pollen), Dallas Mildenhall. If the pollen adhering to the specimen turned out to be predominantly of New Zealand plant species it would show that if not actually collected here the animal had, at the very least, been in this country at some time in the past. No luck. The pollen Dallas was able to collect from the skin surface and the stuffing proved to be all from European plants —

mostly pines, spruces and hops. Although nothing was discovered that would tie the Marseille specimen to a New Zealand origin, neither was anything found that is inconsistent with it having come from here. The most likely scenario — common to many zoological specimens taken to Europe from New Zealand — is that the gecko went to Europe pickled in alcohol and was later prepared as a study skin by a professional taxidermist. HERE TO FROM HERE? Because the Museum d’Histoire Naturelle de Marseille made it quite clear that the loan of H. delcourti was an exception to their general policy, the New Zealang# research was carefully recorded on film, X-rays and transparencies. Because the most convincing proof of a huge gecko in the New Zealand fauna will probably come from the discovery of skeletal remains in cave or dune deposits, the Xrays of the specimen will be used to prepare a reference atlas for palaeontologists working on sub-fossil fauna. Closer to home there might be leads in some lost papers of Frederick Manning or Gilbert Mair both of whom supposedly saw or held specimens of kawekaweau. And finally there is the mysterious story of Jean Aubin and Andreas Reischek. In 1882 when Reischek was in the King Country searching for Maori artifacts he left his cases of specimens reputedly containing some very large stuffed lizards in the care of Jean Aubin, storekeeper at the border town now known as Pirongia.

Maybe somewhere amongst the papers of Reischek or Aubin there is more detail on what these animals were. The negotiations to borrow the H. delcourti specimen, and its subsequent arrival and display, created widespread publicity and the National Museum received a number of fresh reports of very large lizards. Most of the sightings seemed to involve unwitting exaggeration of size or misidentification but a few, particularly one near Gisborne, could not be explained away so easily. There are several, albeit remote, possibilities. Perhaps one of the bigger lizard species that were formerly widespread on the mainland (e.g. Duvaucel’s gecko Hoplodactylus duvaucelii or robust skink Cyclodina alani) or the tuatara still survives on the East Coast or maybe tuatara from offshore islands have been released in the area. Maybe a large species of lizard from Australia has been liberated there. Or, just perhaps, the kawekaweau still lingers on in some remote corner of the country. If it can eventually be proven that the specimen of Hoplodactylus delcourti is indeed from New Zealand, it is almost certainly the animal the Maori people

knew as kawekaweau. Sadly, the lack of confirmed sightings since the 1870s suggest the kawekaweau is now extinct and must join the long list of species that have succumbed to habitat destruction and the impact of introduced predators since humans arrived in this country.

Tony Whitaker is one of New Zealand’s foremost herpetologists. Formerly with DSIR he now works as a freelance ecologist specialising in lizards.