Amongst the casualties were our iconic tree-dwelling koalas, with an estimated 5000 dead in New South Wales alone. They are now officially endangered in three states and territories.

In response, researchers are ramping up captive breeding to prevent extinction. Unfortunately, captive breeding faces two major challenges: it's expensive, and it can be hard to maintain genetic diversity.

To tackle both issues, our new modelling study backs the approach of biobanking (freezing koala sperm) and tailored assisted reproduction techniques. We found these techniques would result in a five-fold decrease in the costs of running captive breeding programs.

Despite their promise, these reproductive tools have not yet become widely used in conservation. With koalas facing an uncertain future, it's time to explore their full potential. If we get this right, we could use the same tools to help other species in rapid decline.