Description and Ecology: Alpine tundra habitats occur in the western United States in Arizona, California, Colorado, Idaho, Montana, Nevada, New Mexico, Oregon, Utah, Washington, and Wyoming. Alpine tundra occurs in most mountain ranges above treelimit, which lies at higher elevations at southern latitudes, and lower elevations at northern latitudes. In Colorado, treelimit varies with slope and aspect but is generally at 3500 m (11,500 ft) elevation. There are an estimated 3 million ha (7.4 million ac) of alpine tundra in the western United States, south of Canada (Brown et al. 1978). Nearly one third of that lies in Colorado, which contains approximately 970,000 ha (2.4 million ac) of alpine tundra. Nearly all of Colorado's alpine tundra occurs in Physiographic Area 62, the Southern Rocky Mountains.

Alpine tundra is comprised of a variety of vegetative communities adapted to specific soils, slope, aspect, moisture, and other environmental influences at high elevations. Tundra habitats are a complex mosaic of boulder fields, fell fields, cliff/rock, wet and dry meadows, and snowfields. Alpine tundra habitats are characterized by shallow soils, short growing seasons, low temperatures, high solar radiation, and high winds. Most precipitation in Rocky Mountain alpine areas falls as snow, often in late winter or early spring, and is distributed non-uniformly because of winds. Because of the severe climate, few vertebrate species, including birds, are able to breed in this habitat.

Importance and Conservation Status: Historically, livestock grazing, mining, reservoir development, and recreation have impacted alpine tundra habitats, and these disturbances have resulted in long-term changes in alpine vegetation. Global warming threatens to reduce the extent of alpine tundra through encroachment of forested communities. Although the avifauna of alpine tundra is small compared to other habitats, these species are typically specialized and endemic, and are not found in other habitats during the breeding season. Further, alpine habitats are fragile; disturbances may take decades or centuries to recover and have long-term impacts on these species.

Priority Species: Current monitoring programs, including BBS, do not monitor species restricted to breeding in alpine tundra habitats of Colorado. These three species are alpine tundra obligates, and indicators of quality alpine tundra vegetation and cliff/rock habitats.