Selecting and Grouping Species of Concern

Using a variety of screening criteria, (e.g., habitat association, estimated risk of extirpation), Wisdom and others (2005a) compiled a comprehensive list of more than 350 sagebrush-associated species of concern. Species of concern were defined as those with populations or habitats that are rare or declining, or both. This list was dominated by vascular plants (68 percent), but also included terrestrial invertebrates (7 percent) and vertebrates (25 percent). For the Great Basin study, this list was narrowed by selecting species suitable for broad-scale assessment in the study area. The screening process yielded 40 species of concern, including 1 amphibian, 9 reptiles, 17 birds, and 13 mammals. Among those selected, greater sage-grouse (Centrocercus urophasianus) and pygmy rabbit (Brachylagus idahoensis) are of particular concern due to recent petitions to list these species under the U.S. Endangered Species Act (USDI Fish and Wildlife Service 2005a, 2005b).

Species groups

The 40 species of concern were assigned to 1 of 5 groups according to similarities in habitat associations and amount of habitat in the ecoregion (Figure on the right; see Table: Composite habitat condition for Great Basin watersheds for a list of species groups). The use of species groups, in combination with individual species, allows managers to:

1. Address either single- or multispecies needs,
2. Identify regional patterns of habitats, especially habitats at risk, that affect multiple species similarly,
3. Address the needs of many species efficiently and holistically,
4. Determine how well regional strategies for groups of species meet the needs of individual species.