Direct fire-induced reptile mortality in the Sierra Morelos natural protected area (Mexico)

Abstract

Little is known about fire as an agent of direct animal mortality, and specifically, there is controversy regarding the effects of fire on reptiles. In the Sierra Morelos natural protected area in Mexico, both unplanned (e.g., man-made illegal and accidental burns) and prescribed burns occur during the dry season. In this study, we assessed direct fire-induced reptile mortality in the Sierra Morelos natural protected area by comparing live and dead individuals. Of the 14 reptile species reported in the area, seven were found dead due to fire. One-third of the individuals found in 2021 (34% of 169 ind.) and 2022 (33% of 33 ind.) were killed by fire. The mean density of detected dead individuals was 1.60 ± 2.99 individuals/ha in 2021 and 0.31 ± 0.27 individuals/ha in 2022. Mortality densities were similar in areas subjected to prescribed burns and in areas affected by unplanned burns (W= 37.5, p = 0.4383). Since our survey likely underestimated the actual mortality caused by fire, our findings show the important direct impact of fire on the reptile community of the Sierra Morelos natural protected area and support the notion that anthropogenic fire can represent a serious risk for reptiles in fragile ecosystems.