9412159 IVES Although diseases are common in many natural animal populations, it is very difficult to document their effects on population abundances because their effects are often subtle and they often act in concert with other processes controlling population densities. This study will investigate the sublethal effects of two types of disease on populations of mountain spiny lizards (Sceloperus jarrovii). Animals in the natural populations will be medically treated to cure them of intestinal worm parasites, malaria, or both with an additional group of lizards left as controls. Subsequently, their growth rate, survival, and fecundity will be measured. Additional studies will be conducted on the physiological performances of infected versus uninfected lizards. Studying the effects of disease in natural populations is important, because disease could be a major impediment to the survival of numerous endangered species.
