NZ scientists in global fight for native frogs

Move over kiwis – if zoologists have their way, the famous New Zealand flightless bird will have to share its national icon status with the country’s native frogs.

Move over kiwis - if zoologists have their way, the famous New Zealand flightless bird will have to share its national icon status with the country’s native frogs.

New Zealand has extremely rare frogs that are among the most endangered in the world. So elevating their image and saving them from extinction should be a major priority, according to zoologist Dr Phil Bishop of Otago University in the South Island.

Dr Bishop is a key driver of the New Zealand Frog Research Group which coordinates conservation strategies for saving the frogs from extinction. The plight of the frog population is so dire that herpetologists worldwide have declared 2008 the International Year of the Frog.

Archey''s frog
Dr Bishop and fellow Otago University scientist, molecular geneticist Associate Professor Russell Poulter are at the forefront of global efforts to save frogs. The two scientists have made a major breakthrough in treating frogs infected with the fungal disease that’s wiped out dozens of species in the last decade.

Three of New Zealand’s seven native frog species have already disappeared and the remaining four are seriously threatened. Among them is the ‘guinea pig’ at the centre of Drs Bishop and Poulter’s discovery - Archey’s frog which is New Zealand’s smallest indigenous species and thought to be the most archaic in the world.

Scientific breakthrough
The scientists have developed a protocol for treating captive frogs infected with the fungus that causes amphibian chytrid disease or chytridiomycosis. Although there are a number of known causes for the current decline in amphibian populations, chytridiomycosis is thought to be the most immediate threat.

Drs Bishop and Poulter have discovered that chloramphenicol, an antibiotic once used widely by humans and still prescribed as an eye ointment, kills the lethal fungus. And their breakthrough is causing a stir among frog enthusiasts worldwide.

Frogs collected from the wild and kept in quarantine have been treated with the antibiotic and found to be completely clear of infection after 63 days. Further testing on other frog species introduced to New Zealand also showed the treatment to be effective.

The protocol is now being tested on six more frog species at Taronga Zoo in Sydney, and there is also interest from scientists as far afield as Honduras, Panama, Puerto Rico and Spain.

EDGE amphibians
Dr Bishop, who has been conducting a lecture series throughout New Zealand, says he wants people to know that all New Zealand frogs are in the top 60 Evolutionarily Distinct and Globally Endangered (EDGE) amphibians.

New Zealand''s native frogs (pepeketua) belong to the genus Leiopelma, an ancient frog group that has changed very little in the last 70 million years. These frogs are found only in New Zealand and three species are already extinct.

It’s estimated that a third of the word’s 6000 or so amphibian species has gone, and that’s happened in the last 15 years.

If frogs continue to be wiped out at the current rate, the earth will see the single largest extinction since the disappearance of dinosaurs.

Dr Bishop says the reason humans should care is that frogs are one of the chief predators of insects and, as well as prey to other animals, amphibians are a vital link in the food chain. Frogs also give excellent early warning signals if the health of the ecosystem is failing.

More information:

Tiny New Zealand frog leaps into conservation history