Density and Composition of Fenced Populations of Leopard Lizards (Crotaphytus wislizenii) in Southern Nevada

Leopard lizards exist in Rock Valley, Nevada, at low densities (1-2/acre) sustained by good adult survival (roughly 50% per annum) and maximal life-spans of at least 7-8 years. Among individuals more than 8 months of age, male survivorship appears to be superior to that of females. Thus, although the sex ratio among hatchlings is about even, there appear to be more adult males than females in our areas. Biomass estimates over a period of 5 years in three 20-acre areas ranged from 17.6 g/acre to 47.8 g/acre. Females do not ordinarily reproduce until 21-23 months of age, but in 1966 a few females reproduced when 9-11 months old. One clutch of eggs per year is typical, but occasionally two clutches may be laid (1965), and in 1964 there was no reproduction.