Twenty-Third Annual Meeting and Symposium of the
Desert Tortoise Council, April 3-5, 1998
Abstracts

As a cooperator in the multi-park Natural Resources Protection Program desert tortoise project, Lake Mead National Recreation Area has greatly expanded its tortoise management program. Since the initiation of the project in 1994, the park has been active both in surveys and monitoring of the species, and in habitat enhancement and protection. We conducted cursory habitat surveys across nearly 850,000 acres of potential tortoise habitat and found that the park has a few high-density “hot spots” with many more medium to low density areas. The Nevada portion of the park, north and west of the Colorado River, has higher tortoise densities than the Arizona side, where tortoise sign is rare. We also established 14 square-kilometer monitoring plots throughout the park. Tortoise sightings on the plots varied considerably, although actual population estimates could not be determined due to small sample sizes and low recapture rates. For plots that were visited multiple times, the continual discovery of unmarked tortoises and the low occurrence of recaptures suggests that the number of tortoises occupying a site is probably much larger than our original findings indicate, and additional surveys and monitoring would help to better define the populations. We also built a burro exclusion fence, removed feral burros, and closed and rehabilitated non-system roads in an effort to protect and enhance habitat for the species.