ECOLOGICAL STUDIES OF SMALL VERTEBRATES IN PU-CONTAMINATED STUDY AREAS OF NEVADA TEST SITE AND TONOPAH TEST RANGE W. Glen Bradley and Kenneth S. Moor University of Nevada, Las Vegas ABSTRACT Various standard census methods were employed during the period March, 1972-May, 1975, to obtain a qualitative and quantitative inventory of the vertebrate biota in seven Nevada Applied Ecology Group (NAEG) intensive study areas of the Nevada Test Site (NTS) and Tonopah Test Range (TTR). In general, vertebrate populations in NAEG study areas correspond with earlier investigations of populations in uncontaminated study areas, | Animals known to be residents in the study areas for at least three months were sacrified and autopsied. Tissue samples for radioanalysis included pelt or skin, GI tract, and carcass. Over 300 tissue samples have been collected and shipped to laboratories for 239Duy and 24han determinations. However, many of these data are forthcoming. Exami- nation and discussion of many aspects of Pu and Am uptake await completion and receipt of laboratory analyses. Data are presented on Pu and Am tissue burdens in Dipodomys mtecrops, a granivorous rodent, from three study areas of NTS and TTR. Ratios of Pu/Am were significantly lower in the carcass than in the pelt or GI tract in this rodent, whereas ratios in tissue of lizards were uniform. A general trend of preferential Am uptake is suggested in certain rodents. It is suggested that the food habits and burrowing behavior of these rodents may be contributing factors to this apparent trend. 53