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Wildlife & Habitat

Woods Bottom 512 x 219

Ouray Refuge is one link in the chain of sparsely distributed wetlands along the Green River corridor that provide much needed habitat for migrating birds. Refuge habitats include the river, riparian woodlands, wetlands, artificial impoundments, croplands, semidesert shrublands, grasslands, and clay bluffs. This diversity of habitat types provides food and shelter for a wide variety of wildlife.  Historically, waterfowl were given management priority on the Refuge. However, Refuge management is now focused on maintaining a variety of native habitats and wildlife with emphasis on all migratory birds, threatened and endangered species, and species of special concern.

 


Riparian/Riverine Habitats

The riparian habitats found along the Green River at Ouray Refuge are made up of cottonwoods, willows, and many other plants that are restricted to floodplains or areas with permanent underground water supplies. Similarly, many wildlife species depend on riparian plants to fulfill their life needs. Thousands of migrating songbirds rely on riparian habitat for refueling as they travel north to their breeding grounds, and other songbirds stop to nest.  In the riparian woodland, cottonwoods, willows, and currant provide cover for cottontail rabbits, raccoons, mule deer, elk, bobcats, and porcupines. Raptors, including bald and golden eagles, great horned owls, and several species of hawks, also use this habitat.


Water development has caused the Refuge riparian habitats to change over time. The riparian area along the Green River has been affected by the Flaming Gorge Dam. Before construction of the dam, the Green River’s water levels responded solely to the uncertainties of nature. Flooding usually occurred in the spring, tapering off to reduced flows in summer. Spring flooding was the primary source of water for the natural wetlands bordering the river.  After construction of the dam in 1962, people began to control the river flows. Human control has resulted in a decrease in spring floods and a reduction in the amount of sediment carried by the river. This has resulted in the gradual deepening of the river channel, further reducing the likelihood of flooding. This makes it difficult for tree and willow roots to reach water and inhibits the germination of new seedlings within the riparian habitat.  

 

The river is used by four endangered fish - the Colorado pikeminnow, bonytail, razorback sucker, and humpback chub - as well as catfish, beaver, river otter, sandhill cranes, bald eagles, and waterfowl.  The four fish species became endangered because of altered flows in the Green River that interfered with their development stages, and increased numbers of invasive fish species such as northern pike and smallmouth bass that compete with the endangered fish for food and prey on their young. 


Riparian cottonwood forests are aging and not being replaced. Instead, nonnative, invasive species such as perennial pepperweed, tamarisk, and Russian olive are overtaking this habitat. These invasive species do not provide forage or appropriate nesting cover for the wildlife species that rely on this area. Refuge management activities based on research are ongoing to help determine how to increase the regeneration of new cottonwoods and willows in the riparian areas. 

Wetland Habitat

Wetlands at Ouray Refuge provide essential foraging and resting grounds for migratory waterfowl during their spring and fall migrations.   During the summer, these wetlands provide critical nesting habitat for shorebirds and waterfowl. Five bottomlands within the river flood plain - Johnson Bottom, Leota Bottom, Wyasket Lake, Sheppard Bottom, and Woods Bottom - are fed by the river as it winds through the desert. In late May, as natural flooding occurs, ponds are formed, spurring the growth of semi-aquatic plants which provide food and cover for ducks and other wildlife. In addition, these ponds serve as nurseries for the endangered fish species of the Colorado River system.  

Grassland Habitat

Grassland plants provide nesting cover for waterfowl, northern harriers, and songbirds such as the savannah sparrow. The grasslands also provide habitat for small mammals, like the montane vole, and crucial winter range for elk and mule deer. Over time, vegetation in the grasslands becomes heavily matted, and its habitat value decreases. The Refuge staff uses prescribed fire to remove the matted vegetation which restores the grassland habitat.  

Cropland 

On drier portions of the Refuge, approximately 150 acres of land is cultivated by local farmers under a cooperative agreement. Crops planted include alfalfa, grass, barley, and sorghum. A portion of the crop produced is left behind to provide supplemental food and cover for numerous wildlife species.  

Upland Habitat

Greasewood, rabbitbrush, and cacti compete for the limited water of the higher, drier semidesert shrublands. Prairie dogs, jackrabbits, and coyotes are typical residents of this upland habitat type. In May and June, the desert is painted with the colors of an amazing variety of wildflowers. These uplands are also home to the endangered Uintah Basin hookless cactus.  

Habitat Management Tools

In their continuing effort to enhance Refuge habitats, the Refuge staff use a variety of management tools, such as prescribed burning, native plant seeding, big game hunting, and control of invasive weeds. On thousands of acres, invasive plant species, such as perennial pepperweed, cheatgrass, tamarisk, and Canada thistle, have become dominant, greatly reducing the value of the habitat available to wildlife on the Refuge. Biological, mechanical, and chemical controls are used to manage these invasive plants.

 

 

 

Page Photo Credits — Woods Bottom: USFWS photo
Last Updated: Apr 11, 2014
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