Influence of size, sex, and reproductive status on the thermal biology of endemic Florida scrub lizards

Does urbanization impact terrestrial vertebrate ectotherms across a biodiversity hotspot?

Urbanization is increasing at an alarming rate altering biodiversity. As urban areas sprawl, it is vital to understand the effects of urbanization on biodiversity. Florida is ideal for this research; it has many reptile species and has experienced multiple anthropogenic impacts. Herein, we aim to evaluate human impacts on registered reptile richness across an urbanization gradient in Florida. The expectation is that highly urbanized areas would harbor a lower number of species. To represent urbanization, we used Venter et al. (2016) human footprint index. We downloaded georeferenced occurrence records from the Global Biodiversity Information Facility to collate species richness. We ran generalized linear regressions controlling for spatial autocorrelation structure to test the association between urbanization and reptile records across Florida. We found a positive association between urbanization and registered reptiles across Florida for total and non-native species richness; however, a lack of association occurred for native species. We performed rarefaction curves due to an inherent bias of citizen science data. The positive association was supported for non-native reptile species richness with greater species richness located at urban centers. Interestingly, total and native species richness were largest at low as well as moderate levels of urbanization. Thus, moderately urbanized areas may have the potential to harbor a similar number of reptile species compared to areas with low urbanization. Nevertheless, a difference exists in sample completeness between the urbanization categories. Thus, a more systematic monitoring of reptile species across an urbanization gradient, not only focusing on urban and wild areas but also including moderate levels of urbanization, is needed to provide informed conservation strategies for urban development planning. Advances in environmental sensors, environmental DNA, and citizen science outreach are necessary to implement if we are to effectively monitor biodiversity at the accelerated rate of urbanization.

Season-sex interaction induces changes in the ecophysiological traits of a lizard in a high altitude cold desert, Puna region

Functional traits are those characteristics of organisms that influence the ability of a species to develop in a habitat and persist in the face of environmental changes. The traits are often affected by a multiplicity of species-dependent and external factors. Our objective was to investigate thermal biology of Liolaemus ruibali in a high altitude cold desert at the arid Puna region, Argentina. We address the following question: do sex and seasonal variations in environmental temperature induce changes in the ecophysiological traits? We measured and compared the operative temperatures between fall and spring; and between sexes and seasons, we compared the ecophysiological traits of lizards, microenvironmental temperatures and thermoregulatory behavior. Air and operative temperatures were different between seasons. We found an effect of season-sex interaction on field body temperatures, preferred temperatures, panting threshold and thermal quality. The voluntary and critical temperatures presented seasonal variation in relation to changes in environmental temperatures, suggesting thermal acclimatization. We note behavioral changes between seasons, with the substrate being the main resource for gaining heat in spring. We conclude that Liolaemus ruibali is an efficient thermoregulator; it is a eurythermic lizard and presents phenotypic plasticity in different ecophysiological and behavioral traits induced by sex and seasonality. In addition, we predict that this population could buffer the effects of projected global warming scenarios.