Habitat use and microhabitat selection of two lizard species with different niche requirements in a resource availability gradient

Human alteration toward environment modifies the spatial distribution of available resources that influences habitat selection in animals. Thus, it is necessary to identify the resources that determine species occurrence in modified landscapes to provide the basis for future conservation efforts. We evaluated the habitat use and microhabitat selection of two lizard species with different niche requirements in a resource availability gradient caused by disturbance. Surveys were conducted in El Cielo Biosphere Reserve, Mexico, during 2016 and 2017. The gradient was grouped in four environmental types in the function of climatic (temperature and humidity) and structural variables (included different measures of soil, substrate, and vegetation coverage). For each lizard, 11 variables related to the microhabitat structure were recorded. Microhabitat selection for each environment type along the gradient was determined and compared via discriminant analysis. The results showed that Sceloporus variabilis, a species that uses a wide range of resources, can select different microhabitats along the gradient; while Lepidophyma sylvaticum, a species with a restricted use of resources, select microhabitats with similar specific characteristics and avoided disturbed areas with scarce canopy cover. This differential response was related to the degree of specificity in resources selection and physiological restrictions of each species.