Microhabitat Use and Home Range Characteristics of Blunt-nosed Leopard Lizards

We used radiotelemetry to determine habitat use and home range characteristics of 16 blunt- nosed leopard lizards (Gambelia sila) at two sites on the Naval Petroleum Reserves in California. Space use parameters of eight lizards occupying an area of relatively dense vegetation in 1982 and eight lizards inhabiting a sparsely vegetated site in 1984 were compared. Home range size, core area size, and amount of overlap of ranges did not differ significantly between sites. The difference in average home range size between males (4.24 ha) and females (2.02 ha) was borderline significant (P = 0.054). Female home ranges and core areas were overlapped extensively by male ranges (x = 79.8% and 50.3%, respectively). There was no evidence of intrasexual overlap of core areas. Male home ranges overlapped the ranges of up to four other males but female ranges did not overlap one another. At the more densely vegetated site, leopard lizards used washes significantly more than grassland, floodplain, and road habitats and they used grassland significantly less than other habitats. At the sparsely vegetated site, grassland was used more than wash habitat and hills were used less than all other habitats. Our data indicate that leopard lizard activity is concentrated in washes and other open areas when herbaceous cover is dense, but they are capable of utilizing the more extensive grassland habitat if vegetation is sufficiently sparse. Creating open space within the grassland habitat may have important management implications for this species in some areas.