Fire transforms the structure of natural habitats and, consequently, modifies microclimates affecting ectotherm organisms that are particularly susceptible to changes in the thermal environment. Nevertheless, the effects of fire-induced microclimatic shifts upon natural populations have been neglected. We measured the central tendency and variation of habitat structural and microclimatic variables in experimental plots of Neotropical savanna vegetation subjected to different fire regimes (control, biennial/early dry season, biennial/mid dry season, biennial/late dry season, quadrennial/mid dry season; one 10 ha replicate of each) and assessed their effects upon lizard community structure (15 species). In addition, we evaluated the underlying mechanisms linking fire-induced environmental changes to community structure, by comparing lizard body condition and survival between different fire regimes. A guided regularized random forest (GRRF) analysis indicated that fire suppression promoted increased tree density, canopy cover and leaflitter weight, whereas burning had the opposite effects, reducing the habitat structural complexity. A redundancy analysis (RDA) indicated that (1) the best predictors of fire regimes were means of structural variables, but variances of microclimatic variables and (2) the reduced structural complexity of burned plots both increased and decreased the variation of microclimatic variables. A canonical correspondence analysis (CCA) revealed that lizard community structure was chiefly influenced by a gradient of decreasing tree density, canopy cover and leaf litter weight with increasing fire severity. About half of the lizard species were favored in the fire-protected plot, while the other half was favored in the burned plots, with most of the variation being explained by structural variables. Lizard body condition and survival rates were not affected by fire regimes, suggesting a dominant role of thermoregulation opportunities afforded by habitat structure-instead of food availability or predation rates-upon community structure. Our findings indicate that even sporadic fires can have profound effects upon lizard communities and that protecting some habitat patches from burning is essential to maximize lizard diversity in Cerrado landscapes.

Disturbance caused by anthropogenic fires are increasingly affecting the biodiversity of fire-prone ecosystems worldwide. The Cerrado biodiversity hotspot suffers higher deforestation rates than Amazonia and concentrates most of the burned areas in South America. To support adequate fire-management decisions in Cerrado, knowledge on the effects of altered fire regimes upon its animal populations is necessary. Based on a long-term, large-scale fire experiment, we investigated the effects of different fire regimes on the demography of the gymnophthalmid Micrablepharus atticolus, an endemic lizard of the Cerrado. Because M. atticolus is more abundant in open habitats, we predicted that frequent burns should favor its populations. Over eight years, we conducted a mark-recapture study using pitfall trap arrays in five 10 ha plots of cerrado sensu stricto, subjected to prescribed burns. Using generalized linear mixed-models of time series data and an information theoretic approach to select demographic models, we describe the life history of M. atticolus and assess the response of apparent survival, detectability, and recruitment to burn regimes and climate variation. Micrablepharus atticolus has an annual life cycle, with complete annual population turnover; breeding takes place during the dry season, when activity is higher, and hatchlings appear in the wet season. Apparent survival, detectability, and recruitment increased in the short-run after the passage of fire in all experimental plots. In the long run, however, both fire-suppression and more severe fire regimes were seemingly detrimental, presumably by affecting microclimatic conditions and food availability. Short-term studies may not adequately describe the effects of fire on the demography of lizard populations. Adequate fire management is warranted for biodiversity conservation in Cerrado, both inside and outside protected areas, including a reduction in the frequency and severity of burns in open physiognomies and controlled, patch mosaic fires to prevent excessive fuel accumulation in denser physiognomies. Fire Regimes and the Demography of the Lizard Micrablepharus atticolus (Squamata, Gymnophthalmidae) in a . 2012. Adaptive responses and disruptive effects: how major wildfire influences kinship-based social interactions in a forest marsupial. Molecular Ecology 21:673-684. : Multi-model inference. Available from: http://CRAN.R-project.org/package=MuMIn. Bates D., Maechler M., Bolker B., Walker S. 2014. lme4: Linear mixed-effects models using Eigen and S4. Available from: http:// CRAN.R-project.org/package=lme4.

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Tail autotomy and regeneration are perhaps the most dramatic adaptations to enhance survival among lizards. In spite of much work on the subject, the ecological significance of tail autotomy rates in natural populations remains elusive, due to difficulties in controlling several confounding factors and the paucity of accurate demographic data. On the basis of a capture-recapture study, we investigate the ecological determinants of tail autotomy rates in Micrablepharus atticolus, a bluetailed lizard from the South American Cerrado. We tested whether habitat (as a proxy of predation intensity), seasonality (as a proxy of intensity of social interactions), ontogeny and sex affected autotomy rates, and also whether autotomy rates affected body condition. We found that tail autotomy rates in M. atticolus are lower than in many other species with brightly colored tails, likely resulting from a small body size and fossorial habits. Autotomy rates were lower than expected by chance in the plot with lower mortality rates, suggesting a more prominent role of predation intensity instead of predator efficiency, and increased with age, suggesting cumulative effects of predation attempts along the ontogeny or age-specific differences in predation intensity. We also found no intersexual differences or any effect of breeding activity on autotomy rates. Our results indicate that energetic costs of tail autotomy are low, or that animals compensate tail loss with increased foraging rates. These characteristics of M. atticolus seem tightly associated with its small body size, fossorial lifestyle and very short life span, and suggest that the costs of tail regeneration should be low.