In late summer, male northern corroboree frogs call for a female mate. It’s a good time to survey their numbers: simply call out “Hey, frog!” in a low, deep voice and the males call back. This year, the survey was vital. Bushfires had torn through the habitat of the critically endangered species. We urgently needed to know how many survived. In late February we trekked into Kosciuszko National Park, through a landscape left charred by the ferocious Dunns Road fire. We surveyed the scene, calling out: “Hey, frog!”. At ponds not severely burnt, reasonable numbers of northern corroboree frogs responded. At badly burnt sites where frogs had been found for 20 years, we were met with silence. The adults there had likely died. After completing our surveys we collected melted cameras we’d deployed eight months earlier to monitor water levels in the ponds. Some weeks later, these would reveal just what the frogs had endured.