Walking through the Bogandyera Nature Reserve, Luke Pearce, a fisheries manager for the Australian state of New South Wales, gestured down a steep hillside and described the scene three days after a wildfire roared through the area on January 11. “There were dead animals all through here,” he said, recalling the carcasses of kangaroos, feral deer, wallabies, wombats, possums, and birds of numerous species strewn across the charred landscape.

Pearce and I were hiking down to a section of the Mannus Creek, a small, high-altitude stream that runs into the Murray River system, Australia’s longest. The Green Valley-Talmal