Feature

Tuatara By Any Other Name

Mislabelling goods is bad, mislabelling animals can be fatal, as protectors of the tuatara have discovered.

By Vicki Hyde

Academic jealousy a century ago may have led to the loss of one tuatara species and may still threaten others that are hanging on by a claw, according to a study by Dr Charles Daugherty of Victoria University.

In the 1800s, a major export trade for many young nations was in scientific specimens. The scientific institutions of Europe vied with each other for more and better examples of new plants and animals from around the globe. New Zealand provided a rich field for naturalists. Thousands of examples of our native flora and fauna found their way to the Old World.

The specimens included hundreds of tuatara pickled in spirits and sent off to natural history institutions. In the British Museum, Dr Albert Gunther closely examined the latest arrival and discovered that it was not a lizard, but an order unto itself. He labelled the creature Rhynchocephalia, or beak head. These days it's called Sphenodontida and, to distinguish it from its fossil relatives, the full name Sphenodon punctatus is used.

Living Fossil

The discovery caused quite a stir. Tuatara were the last representatives of their kind still living. All other Sphenodontida were firmly fossilised, so the creatures were quickly dubbed the `living fossil'. It's a title well earned. Tuatara have been living in New Zealand ever since this country broke away from the huge Gondwanaland continent some 80 million years ago and began its slow drift to the South Pacific. Their lineage goes back even further, however, stretching another 140 million years to the Mesozoic period and the dawn of the Age of Reptiles.

Tuatara provide a direct link to the time of the dinosaurs. Gunther got his pickled `living fossils' from Sir Walter Buller, a New Zealand-born naturalist, ornithologist and editor. Buller had wandered the country collecting plants and animals for the British Museum. His contribution to knowledge was recognised by membership of the Royal Society and by a variety of honours from European scientific institutions.

Sphenodon Species

In 1877, Buller discovered a species of tuatara different from that held by the British Museum. In a move typical of the day, he named it after his colleague and sent an example of Sphenodon guntheri off to the museum for its collection. The specimen, floating in its preservative, is there still, with Buller's faded handwriting proclaiming it guntheri.

Buller's notes suggest that there were a number of other species or subspecies extant, and Daugherty believes that four may well once have been common.

For some reason -- perhaps professional jealousy, Daugherty suggests -- the idea of a number of separate tuatara species never caught on here. Buller's claims were dismissed and the only recognised species was that of S. punctatus.

Buller's scientific credentials may have been dismissed because of the perception of the man as just another animal collector. His personal life was colourful and a scandal associated with the collecting of bird skins from around the country tarnished his reputation.

He wasn't the only one to send New Zealand fauna overseas. In the 1880s, an Austrian naturalist, Andreas Reischek, collected 3,000 bird specimens, 2,500 plants and over 8,000 fish and reptiles for museums. Among this plethora were a number of tuatara which eventually ended up in a Viennese museum. The jars sat on the shelves there, ignored.

It wasn't until 1943, in a Vienna devastated by war, that a thoughtful zoologist realised that the specimens differed from the standard tuatara. Harking back to the discoverer, this subspecies was dubbed S. punctatus reischeki. The specimens are still in Vienna and may well be the last of their kind. S. punctatus reischeki came from Little Barrier Island and the last living representative of that population was seen 12 years ago.

Discovery Ignored

Oddly enough, two world-respected German experts on reptiles, Wermuth and Mertens, acknowledged the different species and subspecies, publishing material on guntheri et al from the 1950s until the late 70s. This research and classification is referenced even now, but the New Zealand scientific community has long ignored it.

Even the International Union for the Conservation of Nature and Natural Resources fails to note more than one species of tuatara, despite using Wermuth and Mertens's research for all other reptiles. The IUCN publishes the respected Red Data List, which provides information on endangered animals worldwide.

Daugherty finds it difficult to understand why the different species have been overlooked for so long. Perhaps it's been a case of scientists not going back to the original research, he suggests. Certainly the isolation of tuatara populations has meant that many scientists have done all their research on pickled specimens.

Misguided Management

Why should this be a problem? Taxonomy is destiny, says Daugherty. If a species isn't named, it isn't recognised as existing and cannot be protected. Bad taxonomy leads to terrible management practices, Daugherty asserts, and he points to the parlous state of a number of potentially unique tuatara populations which exemplify this.

Once found throughout the country, tuatara are now restricted to some 30 offshore islands. Of these, only seven are rat-free and sufficiently large to provide a secure base. Already this century, nine separate populations of tuatara have been wiped out, including S. punctatus reischeki on Little Barrier Island.

Over the last five years, Daugherty and his colleagues have undertaken an intensive study of the different tuatara populations. The tuatara have been inspected, photographed and measured. A comprehensive set of blood samples were taken and analysed genetically to see how closely related the populations are. The genetic tests revealed an interesting fact.

"The most exciting thing was we found that tuatara were not all the same," Daugherty says. "Walter Buller a century ago was absolutely right."

Daugherty believes that there are, or have been, four different populations of tuatara in loose island groupings. These are S. guntheri, now restored to full glory as a separate species, and three subspecies of S. punctatus. Of the latter, one is the apparently extinct Little Barrier Island tuatara, one is the common S. punctatus punctatus, and the last has yet to be given a formal name.

Conservation Implications

"This has quite strong implications for conservation, " says Daugherty. Until now, tuatara have been managed as if they are all one species. If a population on an island is wiped out, it is not thought to present a problem to the species count as a whole. Divide the population into smaller species groupings though, and there are problems.

The Brothers Island tuatara, the newly re-identified S. guntheri, has fewer than 300 individuals living on approximately 1.5 hectares. Its coloration is different from other tuatara populations, with large yellow spots and olive-yellow skin tones.

The island's lighthouse has been automated recently, and the loss of the lighthouse keeper means that the little management provided to date has now gone by the board. The tuatara will have to defend themselves against the incursions of rats, cats and people.

"For the first time in a hundred years there is no protection," Daugherty says.

Ironically, some conservation efforts have placed further pressure on tuatara, with competing bird populations being established on the best rat-free islands.

"The indigenous tuatara are being ignored while introduced birds are being managed," Daugherty says. There may be some hope for the future however. Daugherty is working with the Department of Conservation to implement a management plan for tuatara, and his team have been able to hatch 40 eggs from the Brothers Island group. They plan to raise the young and release them on rat-free islands, and would like to establish a stock in captivity to act as a gene pool.

"A hundred years from now, this will be seen as a turning point", Daugherty exults. It's a turning point that Walter Buller would probably appreciate.

Vicki Hyde is the editor of New Zealand Science Monthly.