The importance of biological surveys in managing public lands in the western United States

Despite previous studies, incomplete knowledge of the mammalian fauna of many national parks hinders our ability to understand the consequences of either management actions of natural disasters to such preserves. Faunal losses have occurred and can be expected to continue (Newmark 1986a, 1986b). our studies in and near Dinosaur National Monument, one of the parks studied by Newmark (1986a, 1986b), have added 11 species to the known fauna. Some species have increased with human impact; other species have either disappeared or are declining. Finally, many species, which are uncommon and poorly known, may have rather specific habitat needs.