Short- and long-term effects of fire and vegetation cover on four lizard species in Amazonian savannas

Abstract

Ecological succession in tropical savannas is limited by seasonal fire, which affects habitat quality. Although fire may cause negligible or positive effects on animals occupying savannas, most short-term studies (months to a few years) are based on a single temporal sampling snapshot, and long-term studies (decades) are rare. We sampled four lizard species (Rainbow Whiptail, Cnemidophorus lemniscatus (Linnaeus, 1758); Striped Whiptail, Kentropyx striata (Daudin, 1802); Grass Anole, Norops auratus Duméril and Bibron, 1837 = Anolis auratus Daudin, 1802; Amazon Racerunner, Ameiva ameiva (Linnaeus, 1758)) in Amazonian savannas to test the effects of fire and vegetation cover on lizard densities at two temporal scales. In the short term, we use three sampling snapshots to test the effects of fire and vegetation cover on estimated lizard densities over the subsequent 1–5 years. In the long term, we test the effects of fire and changes in vegetation cover over 21 years on current lizard density differences. In the short term, species responses were usually consistent with foraging and thermoregulation modes. However, the results were not consistent among species and years, although the variances in species density explained by year as a random factor were generally low. In the long term, the main effects of fire and vegetation cover show that lizard densities may change spatially, but not necessarily temporarily. Wildfire is a natural resource of savannas and apparently have little impact on resident lizards of that ecosystem.