Chuckwalla Habitat in Nevada
Final Report 7 March 2003 Submitted to: Division of Wildlife, Department of Conservation and Natural Resources, State of Nevada STATUS OF DISTRIBUTION, POPULATIONS, AND HABITAT RELATIONSHIPS OF THE COMMON CHUCKWALLA, Sauromalus obesus, IN NEVADA Principal Investigator, Edmund D. Brodie, Jr., Department of Biology, Utah State University, Logan, UT 84322-5305 (435)797-2485 Co-Principal Investigator, Thomas C. Edwards, Jr., Utah Cooperative Fish and Wildlife Research Unit and Department of Fisheries and Wildlife, Utah State University, Logan, UT 84322-5210 (435)797-2509 Research Associate, Paul C. Ustach, Department of Biology, Utah State University, Logan, UT 84322-5305 (435)797-2450 1 INTRODUCTION As a primary consumer of vegetation in the desert, the common chuckwalla, Sauromalus obesus (=ater; Hollingsworth, 1998), is capable of attaining high population density and biomass (Fitch et al., 1982). The 21 November 1991 Federal Register (Vol. 56, No. 225, pages 58804-58835) listed the status of chuckwalla populations in Nevada as a Category 2 candidate for protection. Large size, open habitat and tendency to perch in conspicuous places have rendered chuckwallas particularly vulnerable to commercial and non-commercial collecting (Fitch et al., 1982). Past field and laboratory studies of the common chuckwalla have revealed an animal with a life history shaped by the fluctuating but predictable desert climate (Johnson, 1965; Nagy, 1973; Berry, 1974; Case, 1976; Prieto and Ryan, 1978; Smits, 1985a; Abts, 1987; Tracy, 1999; and Kwiatkowski and Sullivan, 2002a, b). Life history traits such as annual reproductive frequency, adult survivorships, and population density have all varied, particular to the population of chuckwallas studied. Past studies are mostly from populations well within the interior of chuckwalla range in the Sonoran Desert.
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