POPULATION METRICS AND USE OF SALTCEDAR (TAMARIX) HABITATS BY COMMON SIDE-BLOTCHED LIZARDS (UTA STANSBURIANA)

During 2009 and 2010, we observed common side-blotched lizards (Uta stansburiana) in two types of vegetation along the Virgin River in Nevada and Arizona: monotypic stands of nonnative saltcedars (Tamarix) and mixed stands of cottonwoods (Populus fremontii), willows (Salix gooddingii), mesquites (Prosopis), and saltcedar trees. Using mark-recapture techniques, parameters were recorded from 233 individual lizards. We detected no significant difference in parameters between monotypic stands of nonnative saltcedars and mixed vegetation. However, lizards selected habitats having a more open vegetative structure and parameters were correlated negatively with canopy cover. Greatest canopy cover occurred in sites having > 65% stem counts for saltcedar trees. Our results suggest that common side-blotched lizards use habitats with similar structural characteristics in both mixed and nonnative vegetation, and that they avoid sites with dense canopy cover as in the densest stands of saltcedars.