Prairie Grasslands Photo courtesy of WGFD Table of Contents Habitat Description ................................................................................................................................................... 2 Prairie Grasslands Wildlife ....................................................................................................................................... 4 Prairie Grasslands Habitat Threats ......................................................................................................................... 6 Current Prairie Grasslands Conservation Initiatives .......................................................................................... 11 Recommended Prairie Grasslands Conservation Actions ................................................................................ 12 Prairie Grasslands Monitoring Activities ............................................................................................................. 14 Literature Cited ........................................................................................................................................................ 15 Wyoming State Wildlife Action Plan – 2017 Page III – 7 - 1 Habitat Section Wyoming Game and Fish Department Prairie Grasslands Habitat Description often shifted across the landscape through time resulting in a mosaic of habitat diversity (see In Wyoming, prairie grasslands are typically Wyoming Leading Wildlife Conservation below 7,000 feet in elevation and are Challenges – Disruption of Historic predominantly located in the eastern portions of Disturbance Regimes). In addition to the state, although they are also common in disturbances, water availability, often related to basins of south central and southwestern the location of snow drifts, influenced the local portions of Wyoming. In eastern Wyoming, composition of prairie plant communities. prairie grasslands have among the warmest and Prior to European settlement, fires on the Great longest growing seasons of Wyoming’s habitat Plains occurred at intervals of approximately 2– types, as well as relatively deep and well 25 years (Wright and Bailey 1980). Wyoming developed soils. Their location in eastern grasslands likely burned less frequently because Wyoming allows them to receive relatively high they are more arid than the mesic grasslands of summer precipitation, ultimately derived from the Great Plains and thus did not accumulate weather systems originating in the Gulf of fine fuels as quickly (Knight 1994). Mexico which are blocked by the mountains from the basins of western Wyoming. These Much of Wyoming’s prairie grasslands are factors result in grasslands having high primary unsuitable for farming; however, the abundant productivity when compared to other Wyoming grazing resource led to the establishment of habitat types. cattle and sheep ranches. Today, the majority of Wyoming’s prairie grasslands are incorporated Most of Wyoming’s grasslands are classified as within privately owned ranches. The either shortgrass prairie or mixed-grass prairie. predominance of large ranches and Wyoming’s Shortgrass prairie occurs mainly in the southeast relatively low population density have allowed corner of the state and extends south into grasslands to persist in a relatively intact state Colorado. Buffalo grass and blue grama are the when compared to other regions of the country. two predominant grass species in shortgrass Properly managed, livestock grazing can prairie. Mixed-grass prairie is common across duplicate the natural influences of native species much of eastern Wyoming. It typically receives like bison. The future of this habitat type in more moisture and has greater plant species Wyoming will be closely tied to the ability of diversity than shortgrass prairie. Common organizations to engage private landowners in mixed-grass prairie plant species include needle- conservation efforts and the persistence of and-thread, western wheatgrass, blue grama, ranching as an economically viable land use Sandberg’s bluegrass, prairie Junegrass, upland within the state. In addition to ranching, sedges, and Indian ricegrass (Knight 1994). wildlife habitat, oil and gas extraction, wind Grasslands are characterized by frequent and power, recreation, and housing development are occasionally intense natural disturbances important land uses in the grasslands habitat including drought, fire, grazing, and occasionally type. short growing seasons (Nicholoff 2003). These factors have encouraged the predominance of perennial grasses with a substantial number of sedges and herbaceous forbs. These types of plants have their buds at or just below the surface, making them less susceptible to damage by surface fire and grazing (Knight 1994). Historically, regular disturbances created patches of vegetation in various stages of recovery. The size and location of patches Wyoming State Wildlife Action Plan - 2017 Page III – 7 - 2 Habitat Section Wyoming Game and Fish Department Prairie Grasslands FIGURE 13. Wyoming Prairie Grasslands TABLE 13. Wyoming Prairie Grasslands NatureServe Ecological Systems1 1. Inter-Mountain Basins Semi-Desert Grassland 2. Northern Rocky Mountain Lower Montane, Foothill and Valley Grassland 3. Northwestern Great Plains Mixed-grass Prairie 4. Western Great Plains Foothill and Piedmont Grassland 5. Western Great Plains Sand Prairie 6. Western Great Plains Shortgrass Prairie 7. Introduced Upland Vegetation – Forbland 8. Introduced Upland Vegetation – Annual Grassland 9. Introduced Upland Vegetation – Perennial Grassland 10. Recently burned grassland 1 Descriptions of NatureServe Ecological Systems which make up this habitat type can be found at: NatureServe Explorer: an online encyclopedia of life [web application]. Version 7.1. NatureServe, Arlington, VA. http://www.natureserve.org/explorer. Wyoming State Wildlife Action Plan - 2017 Page III – 7 - 3 Habitat Section Wyoming Game and Fish Department Prairie Grasslands TABLE 14. Wyoming Prairie Grasslands sometimes described as decomposer systems, Species of Greatest Conservation Need where solar energy is directed towards wood production, which is digestible only by Mammals specialized fungi, microbes, and insects. Black-footed Ferret Black-tailed Prairie Dog Historically, a number of animal species had a Hispid Pocket Mouse significant influence on shaping the plant and Olive-backed Pocket Mouse animal composition of prairie grassland habitats. Plains Harvest Mouse Estimated bison numbers prior to European Plains Pocket Mouse Sand Hills Pocket Gopher settlement vary considerably, from 15–20 Silky Pocket Mouse million (Cushman and Jones 1988, Shaw 1995) Spotted Ground Squirrel to 30–60 million (Samson et. al 1996). Swift Fox Certainly, large numbers of bison altered White-tailed Prairie Dog grasslands by grazing some areas intensively, which contributed to patches of open habitat Birds and reduced encroachment by trees. Baird’s Sparrow Bobolink Prairie dogs, often thriving in areas recently Burrowing Owl grazed by bison, lived in large colonies, digging Chestnut-collared Longspur burrows and cropping vegetation. These Dickcissel burrows and the open patches of ground Ferruginous Hawk Grasshopper Sparrow resulting from the colonies create habitat for Long-billed Curlew other wildlife species, including the black-footed McCown’s Longspur ferret, burrowing owls, long-tailed weasel, Mountain Plover mountain plover, and swift fox (Kotliar et al. Short-eared Owl 1999, Kotliar 2000). Prairie dogs also provide a Swainson’s Hawk prey base for carnivores including black-footed Upland Sandpiper ferrets, ferruginous hawks, and golden eagles. Reptiles Burrowing mammals, such as prairie dogs, Great Plains Earless Lizard increase the structural diversity of grassland Greater Short-horned Lizard habitats by providing subterranean cover from Northern Many-lined Skink Ornate Box Turtle the elements. Soil burrows are warmer in Plains Black-headed Snake winter, cooler in summer, more humid year- Plains Hog-nosed Snake round, and essentially windless compared to the Prairie Lizard ground surface. This burrowing activity is Prairie Racerunner parallel to the function that primary cavity excavators such as woodpeckers provide in Amphibians forest habitats. Most Wyoming prairie Great Plains Spadefoot grasslands have a strong shrub component in Great Plains Toad addition to grasses. Shrubs also contribute to Plains Spadefoot the structural diversity of prairie grasslands habitat by providing sites for perches, snow- Prairie Grasslands Wildlife capture structures, wind breaks, nest cover, and an additional forage base for ungulates. Key Grasslands are known to support large numbers habitat components, such as high structural of wildlife. They are sometimes described as diversity of grasslands, high diversity of grazer systems, because photosynthesis entrains invertebrates, and diversity of seed crops, will solar energy into grass, which is digestible by a increase the value of these habitats for these wide range of animals. In contrast, forests are mammals, especially pocket mice. Wyoming State Wildlife Action Plan - 2017 Page III – 7 - 4 Habitat Section Wyoming Game and Fish Department Prairie Grasslands Prairie grasslands are home to some of with human encroachment. In some areas of Wyoming’s best known wildlife species Wyoming this trend is now reversing. including the pronghorn and the western meadowlark, Wyoming’s state bird. Prairie Wyoming once represented the western sharp-tailed grouse are a