Fire‐disturbed landscapes induce phenotypic plasticity in lizard locomotor performance

Phenotypic plasticity can occur in response to environmental fluctuation and can bring about pronounced changes in behavioral, physiological, or morphological traits. Anthropogenic habitat modifications, such as prescribed fire, can provide insight on the phenotypic response of ectotherms to structural habitat change. Our objective was to quantify the effect of fire‐altered landscapes on the locomotor performance of the eastern fence lizard (Sceloporus undulatus). Lizard sprint performance was compared among three habitats with different fire histories: a control habitat, which had not experienced fire in more than 60 years, a recovering habitat that had not experienced fire in 4 years, and a recent burn habitat that burned less than 6 months prior to the study. There were significant differences in locomotor performance among lizards from the different habitats (indicative of phenotypic plasticity), and lizards in the recent burn habitat had significantly higher maximum sprint speeds than lizards in recovering and control habitats. To measure the consistency of locomotor performance within individuals, lizards were captured and raced during the field seasons of 2014 and again in 2015. Locomotor performance was significantly repeatable across years, suggesting lizard populations contain considerable individual variation, despite this trait being closely tied to fitness. To the best of our knowledge, this is the first study to observe individual between‐year repeatability in performance of free‐ranging S. undulatus. Lizards had similar body condition among habitats suggesting that nutritional status did not play a role in performance plasticity. Habitats differed both structurally and thermally, and less restrictive thermal regimes in recently burned habitats appear to be the underlying mechanism permitting increased lizard locomotor performance. We found differences in locomotor performance among eastern fence lizards from contrasting habitats with different burn histories (indicative of phenotypic plasticity). Lizards in recently burn habitat had significantly higher maximum sprint speeds than lizards in recovering and control habitats. Locomotor performance was significantly repeatable across years, suggesting considerable individual variation, despite this trait being closely tied to fitness.