Grand Valley Audubon Society
2924 Ronda Lee
Grand Junction, CO 81503
* Riparian Habitats encompass a small percentage of the surface area of the west, but a disproportionate number of bird species depend on it for nesting, wintering, and migration.
* High elevation riparian zones are dominated by several species of willow that are inhabited by Lincoln Sparrows, Wilson's Warblers, Fox Sparrows, Dusky Flycatchers, and several other species.
* At mid elevations, narrowleaf cottonwood and willows host Yellow and MacGillivray's Warblers, Warbling and Solitary Vireos. Many species from the adjacent upland habitats also use the narrow riparian corridors, contributing to the richness of this zone.
* Below 6500 feet, the Fremont Cottonwood/Sandbar Willow complex historically provided rich nesting habitat for a wide variety of birds in its canopy, cavities, and undergrowth. Bullock's Orioles, Western Kingbirds, American and Lesser goldfinches, Western Screech-Owls, Yellow-billed Cuckoos, and Willow Flycatchers all depend on this habitat.
* Human activities have greatly altered the natural history of western riparian corridors, especially those at lower elevations.
* Introduced plants--especially saltcedar and Russian olive--now occupy thousands of acres formerly dominated by a cottonwood/willow riparian woodlands.
* Irrigated agriculture in effect broadens the riparian zone, probably benefitting some riparian bird species by expanding the available habitat. Others--especially those like Yellow-billed Cuckoos and Willow Flycatchers that are pecularly associated with cottonwood/willow--have declined.
* Some birds freely use the introduced saltcedar and Russian olive, but the avifauna supported by them is not as rich and varied as that supported by the native cottonwood/willow habitats.