Feral cats, rats, land clearing, and population growth are all contributing to species extinction around Australia, even in remote places like Christmas Island.

Hundreds of feral cats have wreaked havoc on the island directly contributing to the disappearance or demise of up to 19 species of animals.

But locals and rangers are fighting back with traps, desexing initiatives and poisoned sausages.

In five years it's hoped the island will be entirely feral cat free.

Dion Maple is the Invasive Species Project Officer on Christmas Island.

He says the feral cat problem on the island is very serious.

'The species that are found here are found nowhere else on earth. A lot of them, the remoteness of having evolved here over thousands of years, they are somewhat naive so if a predator arrives that they are not exposed to, they don't know how to respond to them,' Mr Maple said.

Just recently the last of a species of forest skink, named Gump, died. Gump was being kept in captivity.

'(She) died of old age. Gump was quite an ancient species, and it was quite a sad event for us but we feared it was inevitable,' Mr Maple said.

As part of the eradication program, all domestic cats are being desexed, stray cats have been caught and removed, and feral cats are being trapped, shot and baited.

Poisoned sausages are being strung up from branches on the town's edge and in dense forests.

But they're positioned high enough off the ground so that crabs can't reach them.

Already 500 cats have been removed from the island.

Areas where the cats have been removed have witnessed a significant return of coastal nesting birds. In just one year, the birds numbers have almost doubled.

Islands around Australia are increasingly being used as safe havens for threatened species.

These include Tasmania's Maria Island, several islands off the NT coast, and islands off the WA coast have been used as wildlife insurance policies.

John Woinarski is Professor of Conservation Biology at Charles Darwin University.

He says islands serve as important refuges for Australian fauna where threats from introduced species including foxes, cats and rats do not exist.

'It's a short term security operation... The long term objective is to bring them back to the mainland.'

'Ideally we'd like to get rid of the threats across the mainland,' Prof. Woinarski said.

He says community attitudes towards our native animals are changing and he is hopeful all species currently under threat will be saved.