HOME-RANGE ECOLOGY OF AN INTRODUCED POPULATION OF THE EUROPEAN WALL LIZARD PODARCIS-MURALIS (LACERTILIA, LACERTIDAE) IN CINCINNATI, OHIO

A 2-yr field study of introduced wall lizards, Podarcis muralis, revea led a resident population which remained remarkably stable (n = 37 liz ards for each year). Slightly more than half of the 167 wall lizards o riginally captured and marked disappeared from the study sites and wer e 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 b etween males. There was no difference between the sexes with respect t o mean percentage of home range overlap in 1990, but females exhibited greater percent overlap in 1998. 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 h ierarchical 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 result s in light of recent findings regarding lizard spacing patterns, optim ality theory and predictions concerning introduced lizard populations. We also compare our data on one of the only successfully introduced l acertid lizards in North America to data from native European populati ons.