Coastal peninsulas around Australia are becoming fortresses against the final extermination of the continent's most endangered animals.

Scientists and local communities are fencing-off coastal peninsulas to re-introduce animals which have already become largely or totally extinct on the mainland, a National Science Briefing heard in Canberra today.

The development has made Australia a leader in the global battle to save the estimated 25 per cent of the world's mammal species now under threat.

Burrowing bettongs, western barred bandicoots and the pale field rat are today breeding successfully on a Western Australian peninsula, shielded from foxes, cats and competitors like the rabbit which drove them from the mainland decades ago.

CSIRO's Dr Denis Saunders told the Briefing that rare animal species are now being reintroduced to the mainland on protected peninsulas in WA, SA and NSW.

"Using peninsulas gives us a good chance of setting up protection against predators. At Heirisson Prong at Shark Bay in WA, we fenced in a 12 square kilometre area with a buffer zone where we tracked, trapped and poisoned foxes and feral cats.

"The burrowing bettong population now on the peninsula is the first wild population on the mainland in 50 years."

CSIRO's Dr Judy West said that so far 249 recovery plans for endangered native plant and animal species were being implemented and many more were on the way under the nation's "Back From the Brink" recovery program.

Australia presently has 1106 species listed as endangered or vulnerable ­ including 886 plants, 82 birds, 52 reptiles and 50 mammals. Recovery plans for about one third of these have either been prepared or are in preparation.

Australia is also among the world leaders in the artificial breeding and preservation of critically endangered species from all round the world, the director of the Animal Gene Storage and Resource Centre of Australia, Dr Ian Gunn, said.

Established by Australian zoos and universities the AGSRCA has set out to preserve the breeding material from animals such as the greater bilby, the northern hairy-nosed wombat, the dingo, the brush-tailed wallaby, the arctic golden cat and the snow leopard.

"A national program has now been established to salvage and preserve reproductive tissues from these populations in an attempt to maintain their genetic diversity ­ or, as the last resort, the genetic foundation of the species," Dr Gunn explained.

The work mainly focuses on the freezing of sperm, eggs, embryos, ovaries, testes and body tissues of the target animals. Kept at temperatures between -80 degrees Celsius and -196, they can remain viable for future breeding use for many years.

Work is under way on a new technique which will enable a common species to give birth to a related but extremely rare species, by implanting the nucleus of the endangered animal's egg within the egg casing of the common species and then implanting it in a female of the common species.

In this way a common animal, such as the southern hairy-nosed wombat, could become a surrogate parent to a rare one, the northern hairy nosed wombat, Dr Gunn said.

But the ultimate technology for saving very endangered animals is expected to be cloning ­ the exact copying of a living individual from the genes in its body cells, as demonstrated recently by British scientists in the case of "Dolly" the sheep.

Dr Gunn said freezing and artificial breeding methods were not a substitute for preserving the habitat of endangered animals and the maintenance of wild populations ­ but, faced with complete extinction, they could play a role of last resort and guarantee their survival.

More information:
Dr Denis Saunders, CSIRO 02 6242 1661
Dr Judy West, CSIRO 02 6246 5113
Dr Ian Gunn, AGSRCA 03 9550 5470