Australia is in the grip of its worst wildfire season on record. The human death toll stands at 28, and thousands of homes have been destroyed across more than 10 million hectares of land - an area larger than Portugal. An estimated 1 billion wild mammals, birds and reptiles have perished. Michael Clarke, an ecologist at La Trobe University in Bundoora, Melbourne, has been studying the effect of fires on native ecosystems - and how they recover ever since a fire tore through his field site 15 years ago. Clarke spoke to Nature about how animals fare in the wake of wildfires, and why this season's fires could prove particularly devastating.