Effects of repeated fire events on the body condition of the cricetid rodent Rhipidomys macrurus in the Brazilian Cerrado

Abstract Environmental disturbances may cause physiological, behavioral and demographic changes in wildlife populations, which may translate into changes in community structure and ecosystem functioning. Little is known about fire effects on physiological parameters, and their consequences for population dynamics and persistence. Due to ongoing climate change and anthropogenic pressures, fire has become more intense and frequent in several Brazilian biomes, including the Cerrado. This suggests an urgent need to assess fire’s impact on organism physiology, especially nutritional indicators. We used a longitudinal database (9 years) to test the effects of fire on the body condition of the long-tailed climbing mouse Rhipidomys macrurus at the Panga Ecological Station (Uberlândia/Brazil). The effects of sex and climatic season were also tested. Overall, we failed to corroborate our hypothesis, as body condition was not significantly affected by repeated fires. Several mechanisms may account for this result: (1) reduced intraspecific competition after repeated fire events, due to abrupt density changes, (2) fire acting as a selective agent, increasing mortality of individuals with lower body condition and nutritional reserves, and (3) behavioral strategies that may compensate for energy loss and reduce negative fire impacts on body condition. Furthermore, we cannot discard the possibility of a false negative, due to reduced statistical power resulting from low sample size after fire events. Finally, other fitness metrics may be more affected by fire than body condition. Our results support the theory that body condition may be an unreliable indicator of habitat quality, disturbance, and individual or population health.