VARIATION IN HOME RANGE OF THE SIDE-BLOTCHED LIZARD,UTA STEJNEGERI, IN COAHUILA, MEXICO

Abstract

We studied seasonal variation in size and fidelity of home range in a population of eastern side-blotched lizards, Uta stejnegeri, in southern Coahuila, Mexico. Field work was carried out during the active seasons of 2002–2004. Home ranges during breeding and non-breeding seasons were larger for males than females and were reduced in both sexes during non-breeding months (autumn). There was greater intersexual overlap of home range during summer and less in autumn. Intrasexually, males had more overlap in home range than females (particularly during summer), which could be related to their large home ranges during that season. Fidelity to home range from one season to the next in a given year was similar in males and females. Although males had greater length and mass than females, neither measure correlated with size of home range. Density of adult lizards was negatively correlated with size of home range during the reproductive period. During non-reproductive months, density of all age classes combined was negatively correlated with size of home range. Our results indicate that home range sizes of U. stejnegeri vary considerably over the year and diverse factors are involved.