TRA biologists regularly conduct special-status species surveys, vegetation and habitat surveys, and prepare biological assessments and management plans. Staff is familiar with all of the research methods and databases that the resource agencies expect to see in biological site assessments, including the California Natural Diversity Database, the Wildlife Habitat Relationships Database, the Manual of California Vegetation, state and federal survey protocols, California Native Plant Society protocols, and the usual field guides and floras. We have expertise in assessing the potential occurrence of many special-status species, including California red-legged frog, California tiger salamander, many butterfly species, birds such as burrowing owl, and mammals such at San Joaquin kit fox, dusky- footed wood rat, and bats.

When needed, TRA works with a network of subcontractors with special expertise in particular endangered species. Such individuals are selected based on their demonstrated ability and knowledge with particular species, as well as possession of U.S. Fish and Wildlife Service permits and California Department of Fish and Game authorizations where required. The number of these permits is very limited, and if the species must be handled in order to do a survey, an individual or firm with the required permit must be used in the study.