‘Fit and feisty’: Once extinct bandicoots are now running wild on this Australian island

A species once declared extinct on mainland Australia takes its “most significant steps towards recovery” thanks to a world-first genetic rescue programme.

This week, conservationists released up to 100 eastern barred bandicoots onto Phillip Island, a populated coastal island near Melbourne. Each one of the rabbit-sized marsupials had been carefully bred to increase their chances of survival in the wild.

The mission was led by Odonata Foundation, Cesar Australia and the Eastern Barred Bandicoot Recovery Team. Since 2004, conservationists from these groups have been carefully breeding the marsupials, growing the population to a community of over 2,000 individuals in safe havens.

Amazon’s Right Now Climate Fund invested AUD $2.5 million (around €1.52 million) to help restore populations of endangered species, including the largest-ever reintroduction of eastern barred bandicoots in the wild in Australia.

Why was the eastern barred bandicoot declared extinct?

Eastern barred bandicoots are powerful ecosystem engineers thanks to their burrowing habits, which help improve soil health, seed dispersal, water retention and nutrient cycling – all of which strengthens landscapes against floods and droughts.

However, their numbers plummeted in Australia due to a combination of natural predators such as foxes and habitat destruction. By the late 1980s, just 60 remained – found among abandoned cars in a rubbish tip.

These survivors were taken into captivity for breeding. By 1991, they were declared extinct in the wild.

Thanks to conservationists’ efforts, the number of eastern barred bandicoots jumped from 150 to an estimated 1,500 in 2021. This was mainly achieved through creating predator-free sites and moving some of the animals onto fox-free islands.

However, genetic inbreeding means many of these wild animals were unable to thrive. With fewer to mate with, a genetic fault known as ‘undershot jaw’ started to appear in the weak population – making it harder for them to dig, grasp, or chew food.

How genetic breeding is saving the bandicoot

Odonata Foundation has been breeding eastern barred bandicoots from mainland Australia with those from Tasmania – two genetically distinct populations which had been isolated from each other for more than 10,000 years.

By diversifying and strengthening their gene pool, and by selectively breeding females with larger males, Odonata and the Recovery Team has created a “fitter, healthier population of animals with greater genetic diversity, more balanced sex ratios, and increased size”.

The organisation aims to build a population of at least 500 animals across a minimum of five different locations, ensuring that as well as being genetically more resilient, they are geographically dispersed. This means they are less likely to be wiped out by a natural disaster.

“The most powerful part of this story is genetic rescue,” says Dr Andrew Weeks, director of Cesar Australia and science advisor to Odonata.

“Through a world-first gene mixing approach, we’ve built a fit, feisty bandicoot population with far greater genetic health and a much better chance of survival than their inbred predecessors.”

Over the next three years, eastern barred bandicoots released onto islands off the Victorian coast and further sites will be closely monitored through ongoing genetic testing to assess whether the population has stabilised.

“This milestone marks the culmination of many years of dedication and collaboration by the Recovery Team,” says Matt Singleton, Chief Operating Officer at the Odonata Foundation.

“We are also deeply grateful to the Eastern Maar and Bunurong Traditional Owners for their ongoing support in the recovery of this unique and highly significant species with which they have a deep connection, and for the role they have played in helping make this release possible.”

You can learn more about the Odonata Foundation here.