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Living in urban environments presents many challenges to wildlife, including exposure to potentially toxic pollutants. For example, the heavy metal lead (Pb) introduces numerous health problems to all animals, including humans. The little work that has been conducted on lead toxicity in reptiles suggests that lizards may be extraordinarily resilient to very high levels of lead pollution, by either avoiding or mitigating the toxicity. To assess the impact of lead exposure, we measured field blood levels and tested for the effects on ecologically relevant performance measures in common wall lizards (Podarcis muralis) – a small reptile particularly capable of thriving in urban environments. We captured lizards from roadside and park habitats across Cincinnati, Ohio, USA, and quantified the concentration of lead in blood samples (n = 71 adult lizards). Lizards from roadside populations had higher blood lead concentrations than lizards from park populations, and females had higher blood lead concentrations than males regardless of habitat type. We then tested two aspects of lizard performance important for survival: (1) balance, a cognitively demanding task, to assess the effect of lead on cognition (N = 41), and (2) running endurance, an aerobic exercise dependent on oxygen (N = 43), to assess the impact of lead on blood oxygen-carrying capacity. We then used correlation analyses to quantify the relationship between lead levels and these ecologically-relevant performance measures. There was no effect of blood lead levels on running endurance, but contrary to our predictions there was a slight positive effect on balance performance, whereby lizards with higher blood lead concentrations slipped less often than lizards with lower blood lead concentrations. Understanding the effects of lead toxicity and resilience in a particularly resistant animal could help us better respond to public health and environmental pollution concerns. 

This is a short note describing an observation of a trifurcated tail and an analysis of tail regeneration rates of lizards among populations in Ohio. 

Many species exhibit color polymorphisms which have distinct physiological and behavioral characteristics. However, the consistency of morph trait covariation patterns across species, time, and ecological contexts remains unclear. This trait covariation is especially relevant in the context of invasion biology and urban adaptation. Specifically, physiological traits pertaining to energy maintenance are crucial to fitness, given their immediate ties to individual reproduction, growth, and population establishment. We investigated the physiological traits ofPodarcis muralis, a versatile color polymorphic species that thrives in urban environments (including invasive populations in Ohio, USA). We measured five physiological traits (plasma corticosterone and triglycerides, hematocrit, body condition, and field body temperature), which compose an integrated multivariate phenotype. We then tested variation among co‐occurring color morphs in the context of establishment in an urban environment. We found that the traits describing physiological status and strategy shifted across the active season in a morph‐dependent manner—the white and yellow morphs exhibited clearly different multivariate physiological phenotypes, characterized primarily by differences in plasma corticosterone. This suggests that morphs have different strategies in physiological regulation, the flexibility of which is crucial to urban adaptation. The white‐yellow morph exhibited an intermediate phenotype, suggesting an intermediary energy maintenance strategy. Orange morphs also exhibited distinct phenotypes, but the low prevalence of this morph in our study populations precludes clear interpretation. Our work provides insight into how differences among stable polymorphisms exist across axes of the phenotype and how this variation may aid in establishment within novel environments. 

Data files associated with Amer et al. 2023 "Physiological phenotypes differ among color morphs in introduced common wall lizards (Podarcis muralis)" Published in Integrative Zoology.