Toxic toads on the rampage

2001-03-14 12:25

Sydney, Australia - Giant crocodiles and lizards beware: Toxic toads are muscling in on your territory, with potentially disastrous consequences for the world famous Kakadu wetlands.

Sparking fears they will devastate local wildlife, poisonous cane toads have completed their march to World Heritage-listed Kakadu National Park in far northern Australia, scientists said on Wednesday. The toads, imported decades ago from South America to eat beetles in sugar cane fields on the east coast, have been expanding inexorably.

Among animals at threat from the toads, which grow up to 23 centimetres (nine inches), are saltwater crocodiles, which can reach lengths of up to seven metres (21 feet).

Crocodiles have been killed in other areas by eating cane toads, which secrete a powerful toxin if attacked.

Adelaide University amphibian specialist Associate Professor Mike Tyler predicted the toads' impact on Kakadu would be disastrous.

"Cane toads will become the most prevalent and obvious species in a part of Australia renowned for its biodiversity," he said.

The toad is expected to flourish in the Kakadu wetlands, which are recognised as the most outstanding example of biodiversity in northern Australia.

The picturesque park, used as the backdrop for parts of the first "Crocodile Dundee" movie, are a tourist magnet and home to hundreds of species of birds, fish, amphibians and reptiles.

As of this week, cane toads were calling it home too.

Two adult and dozens of juvenile toads were found in a tributary of the Katherine River on the park's southern edge, National Parks director Peter Cochrane said.

Cochrane played down the impact of the unwanted immigrants.

"There will be ecological consequences of their arrival but we do not consider that the park's World Heritage values will be adversely effected," he said in a statement.

Cochrane said quolls, a small catlike marsupial, and water monitor lizards were among the species most at risk from the toads' invasion and their populations would be monitored.

"Some species will suffer some adverse effects, that's the experience elsewhere," he said. "But we're not expecting species-level effects."

Cochrane said the toads' arrival was not all bad news.

"The upside of course is that some feral animals eat them and suffer the consequences as well, so we're expecting a decline in feral pigs and cats. So to that extent we expect there'll be some recovery of some species that have been adversely affected by pigs and cats."

Cochrane said surveys of tourists and tour operators suggested the damage to Kakadu's biodiversity would not affect visitor numbers.

"It really doesn't figure very large on their radar screens as an issue of great concern," he said.

Cochrane said nobody knew what species in Kakadu would be worst affected.

"That's the 64 000 dollar question; ask me again in six or 12 months time," he said. - Sapa-AP

- SAPA