intensive study area (Moor and Bradley, 1974). Permanent live- trapping grids were established in the study areas. Utilizing cap- ture-recapture techniques and a system of toe-clipping to enable individual recognition of animals, data on population densities, biomass, and seasonal activities were gathered. Radioanalysis Individual animals known to be residents in the study areas for at least three months were captured, sacrificed, and taken to the CETO building in Mercury, where they were autopsied. Animals were also collected off-site for analysis following the same procedures used in NAEG study areas. Tissue samples for radioassay included pelt or skin, GI tract, and carcass. Laboratory procedures for preparation of tissue samples have been reported (Moor and Bradley, 1974) and included dipping animals in hot paraffin wax to minimize crosscontamination of respective subsamples. Levels of 241an and 2395, in the tissue samples were determined by LFE Environmental Analysis Laboratories, Richmond, California. Hematological Studies The following procedures were used to obtain base line hematological data from animals collected off-site and will be used to process resident animals collected in NAEG intensive study areas. Animals were captured alive utilizing Sherman live traps or nooses and returned to the laboratory and examined within 24 hrs of capture. Blood was obtained from rodents by a cardiac puncture using ether as an anesthetic. Blood was obtained from lizards by decapitation. In all cases, blood was, collected in heparanized (ammonium sulfate) syringes. All analyses were done in duplicate, and any test exceeding a 1% difference was repeated. All analyses were accomplished follow- ing standard methods (Helper, 1966). 55