skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: The Relative Abundance of Desert Tortoises on the Nevada Test Site within Ecological Landform Units

Technical Report ·
DOI:https://doi.org/10.2172/901934· OSTI ID:901934

Sign-survey transects were sampled in 1996 to better determine the relative abundance of desert tortoises on the Nevada Test Site (NTS). These transects were sampled within ecological land-form units (ELUs), which are small, ecologically homogeneous units of land. Two-hundred and six ELUs were sampled by walking 332 transects totaling 889 kilometers (km) (552 miles [mi]). These ELUs covered 528 km{sup 2} (204 mi{sup 2}). Two-hundred and eighty-one sign were counted. An average of 0.32 sign was found per km walked. Seventy percent of the area sampled had a very low abundance of tortoises, 29 percent had a low abundance, and 1 percent had a moderate abundance. A revised map of the relative abundance of desert tortoise on the NTS is presented. Within the 1,330 km{sup 2} (514 mi{sup 2}) of desert tortoise habitat on the NTS, 49 percent is classified as having no tortoises or a very low abundance, 18 percent has a low or moderate abundance, 12 percent is unclassified land being used by the Yucca Mountain Site Characterization Project, and the remaining 21 percent still has an unknown abundance of desert tortoises. Based on the results of this work, the amount of tortoise habitat previously classified as having an unknown or low-moderate abundance, and on which clearance surveys and on-site monitoring was required, has been reduced by 20 percent.

Research Organization:
National Security Technologies, LLC (NSTec), Mercury, NV (United States)
Sponsoring Organization:
USDOE National Nuclear Security Administration (NNSA)
DOE Contract Number:
DE-AC52-06NA11718
OSTI ID:
901934
Report Number(s):
DOE/NV/11718-245; TRN: US200718%%371
Country of Publication:
United States
Language:
English