Prompt surveys optimise detection of lizard mortality during prescribed fire in southern Australian eucalypt forests

Little is known of the number of vertebrates that die during prescribed fire, which has increased in frequency across south-eastern Australia. The ecological implications of changing fire regimes have received research focus, but numbers of animals killed by fire are rarely reported. Optimal timing of post-fire surveys for the detection of animal mortality is poorly known. To determine the relationship between lizard carcass detection and time since fire, we surveyed a post-fire chronosequence ranging from 0 to 20+ years since fire. Following 10 prescribed fires undertaken in stringybark woodlands of southern Australia, we detected 27 carcasses of four lizard species. Carcass detection decreased with time since fire, with carcasses only found up to 12 days post-fire. Fourteen carcasses were detected immediately (28 h) post-fire, representing 52% of all carcasses, and numbers declined rapidly thereafter, potentially because of scavenging. No carcass was found at unburnt sites. Ground cover and shelters had no effect on carcass detection at burnt sites. To estimate accurately prescribed fire-induced mortality of small reptiles, we recommend surveys immediately after fire with considerations for the behavioural ecology, season of burning, and conservation status of affected species. Such data will be essential to evaluate animal welfare and ecological implications of prescribed fire.