Hematological Studies Base line hematological data obtained from 50 rodents (3 species) and 22 lizards (5 species) from off-site areas of southern Nevada have geen gathered. Blood cell counts and blood composition values for some rodents are presented in Tables 3 and 4. These and additional data from off-site areas will be used as a basis for evaluating blood values obtained from resident animals of NAEG intensive study areas. These animals will be sacrificed in the summer of this year, at which time they will have been residents in Pu-contaminated areas for at least three months. FUTURE PLANS After nearly three years of ecological study, the small vertebrate composition of seven NAEG intensive study areas is reasonably well known. Over 350 vertebrate tissue samples have been collected and shipped for radioanalysis. Based on preliminary data, certain prob- lems and trends are apparent: 1. Access to certain NAEG study areas is limited and unpredictable due to other ERDA activities. 2, Climatic conditions strongly influence small vertebrate activities and population estimates. 3. Pu tissue burdens of animals collected from the same strata and sampling sites are not consistent and vary widely. 4, Pu/Am ratios vary between species, between individuals of the same species, and between tissues of individuals. Some data suggest that there is a preferential uptake of Am in at least certain species. To facilitate a better understanding of population densities and trophic relationships as they relate to Pu and Am availability, uptake, and deposition, the following is proposed: 60 ,