The Herpetological Journal

pp.1-11

Authors: Paulo Sá-sousa

Abstract: The geographic distributions of two forms of the Iberian wall lizard (Podarcis hispanicus) in Portugal were determined through extensive field surveys. Predictive models of probability of occurrence were developed for both forms of P. hispanicus, based on multivariate logistic regression of environmental variables. On a coarse scale, the best-fit models suggested that the distribution of the north-western form of P. hispanicus can be largely explained by environmental variables such as altitude, mean annual temperature and number of frost days per year. The distribution of the south-western form of P. hispanicus is also explained by altitude and temperature, but the type of climate also appears important. Predicted probabilities of occurrence broadly match the known distributions range of the two forms. Where predicted distributions are not confirmed by field surveys, historical and/or interspecific factors may be more important than environmental variables in influencing the distribution of the lizard.

Keywords: Podarcis, wall lizard, distribution, GIS