(Transcript from World News Radio)

Feral cats are in the firing line, as the federal government declares war on the invasive predators.

It's part of a plan to halt the destruction of native wildlife, with populations of small mammals, birds and reptiles declining at an alarming rate.

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Australia is home to numerous small marsupials and mammals that are found nowhere else in the world.

And many are rapidly disappearing.

An estimated 1800 species of plants and animals are under threat.

Domestic animals released into the wild, such as dogs, foxes and feral cats are often to blame.

Darren Grover from enviromental group the World Wildlife Fund says cats are the biggest killers.

"Animals like numbats, bilbies, those kinds of animals that are quite iconic and recognisable to a lot of Australians, their number one killer if you like, is feral cats."

The number of feral cats in Australia is difficult to ascertain.

Some estimates put the number 20 million, killing tens of millions of marsupials and other native animals every night.

Environment Minister Greg Hunt says his new national Threatened Species Strategy will see two million fewer feral cats in Australia by 2020.

"We are drawing a line in the sand today which says on our watch, in our time, no more species extinction. It's tough and a challenge. We can do much and we can do better."

Feral cats will be trapped and baited and so-called "safe havens" provided for wildlife, under the plan.

While conservation groups welcome the attention on invasive species, they say other threats to wildlife, such as habitat loss, also need to be addressed.

The Australian Conservation Foundation's Kelly O'Shanassy says other measures are irrelevant if habitats are destroyed.

"This government is approving habitat destruction through coal mining, through logging and through land clearing and if the little animals lose their home, it really doesn't matter too much what else we do so that is a missing link."

Australia has lost more than 50 animal species since white settlement and has the highest mammal extinction rate in the world.

The Wilderness Society's Amelia Young says this loss needs to be urgently addressed.

"What people need to understand is that extinction isn't something that happens overnight, extinction is a process and what we have are many birds, plants, animals, reptiles and mammals that are on the verge of extinction and also on the spectrum towards extinction."

It's hoped the government's new plan will help halt that decline.