Feral – and threatened? Endangered camels, banteng and hog deer have found an unexpected refuge in Australia

JohnCarnemolla/Getty Millions of large feral animals roam Australia.

Pigs, camels, deer, horses, water buffalo, cattle and goats were introduced deliberately as transport, livestock or to hunt.

Many have since established wild populations.

Governments spend millions every year trying to keep feral animal numbers down because these animals can have strong effects on ecosystems by eating plants and trampling.

In recent decades, populations of these largely herbivorous feral species have grown.

Every Australian knows common myna birds are bad, rabbits are worse and feral cats kill native animals unchecked.

But how do we decide what makes an introduced species “good” or “bad” – and will we ever concede that some species are here to stay? Our new series on invasive species explores these questions.

Dozens of native species have gone extinct since colonisation and many others are in decline.

In response, conservationists have rightly focused on reducing threats to surviving species to stave off further extinctions.

Feral animals are thought to contribute to the problem, alongside fragmented habitats, climate change and the end of most First Nations’ fire regimes .

But there’s a paradox here.

Some feral animals are abundant in Australia – but threatened, endangered or extinct in the wild in their original regions.

For these species, Australia is acting as a last refuge.

How can a feral animal be threatened? Wild herds of dromedaries (one-humped camels) haven’t roamed the deserts of North Africa and the Middle East for about 2,000 years .