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Habitats

Springtime view down Elk Creek, with Arrowleaf Balsamroot blooming throughout grassland.Knowing what habitat an animal prefers – what it likes to eat, where it likes to rest, safety to bear young, a place to find a cool drink of water – provides visitors with an advantage for seeing wildlife. Animals will move between areas to get food in one area, cover in another, and water in yet another. The National Bison Range has some wonderful native habitat within its boundaries. Since the refuge is over 100 years old, the area was never cultivated and much remains as it was. Today, refuge managers and biologists look at the best way to maintain the native habitats by using tools such as prescribed burns and integrated pest management to control non-native invasive weeds and keep native plants healthy.

 Pronghorn herd in open grassland at Bison Range.  Photo by Ryan Hagerty/ USFWS  Intermountain Grassland  

The National Bison Range has one of the largest remaining tracks of intermountain grassland within its boundaries. Grasslands and prairies in general are some of the rarest habitats in North America, since this is where people primarily live and work, grow food and put roads. Up to 75% of the refuge is covered in prairie grasses, particularly important to maintain our largest grazer, the bison. Pronghorn antelope and elk also utilize the grassland ecosystem along with a variety of other mammals, insects, and birds. 

Similar to the Palouse prairie found in Idaho and eastern Washington, the main grasses found at the Bison Range are Idaho fescue, rough fescue and bluebunch wheatgrass although many others can be found. Native bunch grasses grow in clumps and are specially adapted to dry land conditions, receiving about 13 inches of precipitation a year here at the refuge. Intermountain grasslands also contain other broader leaved plants called forbs. The flowering displays occur early in the season (April through June) to avoid the dry summer heat.

Western turtle covered in duck week sunning on log in pond.  Photo by Dave Fitzpatrick/USFWS  Wetland and Riparian Habitat

The open water of ponds, lakes, rivers and creeks provide rich habitat for plants and animals. The larger vegetation, including juniper and large cottonwood trees, provides more shade and higher humidity. Covering only about 3% of the Bison Range, wetlands and riparian areas produce the greatest food biomass of any environment. A wide variety of birds and other wildlife, especially deer and small mammals such as mink, live along wet areas because of the excellent protective cover and wide variation of food sources to be found there. 

Black Bear eating berries in Hawthorn bush.  Photo by Pat Jamieson/USFWS  Shrublands

The shrublands of the Bison Range can be found in hillsides and draws, along small watercourses, and in the forest understory. These areas do not dominate any one area and are scattered over only 3% of the refuge. Many of the dominant bushes produce edible berries - chokecherry, hawthorn, serviceberry, snowberry, elderberry, and wild rose.  

Many bushes are kept low due to browsing by deer but some can reach tree-like heights. This is especially true of the hawthorns whose thorns make it difficult for deer to eat it leaves and buds. This defensive mechanism does not stop numerous birds from eating its berries, though. Watch for cedar waxwings, gray catbirds and bullock’s orioles in the bushes, feeding and nesting. Black bears, which come in all colors, including tan, brown, cinnamon, and of course, black, also enjoy the ripening berries in July and August.

View across grassland looking towards forest at High Point.  Photo by BOW  Forest 

Mountain forest of Douglas fir and Ponderosa pine covers the tops of the hills of about 14% of the Bison Range. Forests typically develop where there is an average temperature greater than 50 degrees in the warmest months and where there is an annual rainfall of about 13 inches. The Refuge has places that meet these requirements, although just barely. Moisture levels have created the natural tree patterns you see on the surrounding hills with trees taking hold at higher elevations where it is cooler and moister, on the cooler north slopes, or where there are depressions to hold the moisture. 

Forest provides cover for deer and elk, which come out to feed in the grassland and shrublands of the refuge. Birds of the conifer forest are adapted to food sources found here. They eat pine nuts from cones, new tree buds, seeds and berries plus insects that live in bark or burrow into the wood. Since most of these things are available all year, many forest birds such as chickadees, jays, grouse, and woodpeckers do not migrate.

Page Photo Credits — Forest at High Point by Liz Lodman/MT FWP.
Last Updated: Mar 21, 2013
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