Home Range Ecology of an Introduced Population of the European Wall Lizard Podarcis muralis (Lacertilia; Lacertidae) in Cincinnati, Ohio

Abstract

-A 2-yr field study of introduced wall lizards, Podarcis muralis, revealed a resident population which remained remarkably stable (n = 37 lizards for each year). Slightly more than half of the 167 wall lizards originally captured and marked disappeared from the study sites and were classified as nonresidents. Males occupied significantly larger home ranges than females and, in 1991, had higher instances of intersexual home range overlap than did females. Instances of female-female home range overlaps in 1991 were more numerous than corresponding overlap between males. There was no difference between the sexes with respect to mean percentage of home range overlap in 1990, but females exhibited greater percent overlap in 1991. Small home range size and high home range overlap suggest that the Cincinnati population may have switched from territorial behavior (reported for European populations) to a hierarchical dominance system, possibly in response to unique pressures (high lizard densities, high predation pressures and low availability of preferred habitat) in the Cincinnati area. We interpret our results in light of recent findings regarding lizard spacing patterns, optimality theory and predictions concerning introduced lizard populations. We also compare our data on one of the only successfully introduced lacertid lizards in North America to data from native European populations.