May 19, 2010
Contact: Georgia Parham
812-334-4261 x 1203
ENDANGERED SPECIES DAY: MAY 21, 2010
Conserving an Endangered Ecosystem: The Northern Tallgrass Prairie National Wildlife Refuge
By Kim Mitchell and Alice Hanley
U.S. Fish and Wildlife Service
Five years ago, the U.S. Senate designated the third Friday in May as Endangered Species Day. This year, Endangered Species Day is May 21, an opportunity to raise awareness about imperiled plants, animals, and habitats, and to demonstrate ways that others can help conserve these resources. The following is an example of the U.S. Fish and Wildlife Service working with others to recover endangered plants, animals and habitats.
Northern tallgrass prairie, once one of the Midwest’s largest and most biologically productive ecosystems, has been reduced to less than one-tenth of one percent of its original expanse and has become almost functionally extinct due to fire control and extirpation of keystone species. Estimates place the original northern tallgrass prairie in Minnesota and Iowa at approximately 25 million acres. Fewer than 300,000 acres remain, most of it scattered in small parcels that often have little or no wildlife value.
Grassland nesting birds, such as dickcissels, bobolinks, and upland plovers, are some of the most imperiled species found in northern tallgrass prairies. They have shown more dramatic, consistent, and widespread declines than any other group of birds in North America. Not surprisingly, their declines mirror declines in quantity and quality of our native grasslands. Besides simply having few areas available for nesting, predation and competition further reduce the chance for grassland nesting birds to survive and have young. Large predators (wolves, cougar, and bear) have been replaced by smaller predators (fox, skunk, and raccoon) that prey extensively on birds, their eggs, and their young.
Grassland birds that nest in prairie fragments are forced to concentrate their nests in small, scattered parcels of habitat characterized by large amounts of edge (the area where prairie meets farmland, lawns, or other types of habitats). The problem with edge, from a bird’s perspective, is that it provides corridors along which red fox, striped skunk, and raccoon hunt, making it easy for them to find ground nests near edges. The more edge and less interior grasslands, the more nests lost to predators. Further, fire control and woody plantings have allowed forest-edge birds to expand from the Midwest oak and Eastern deciduous forests, westward into prairies areas, adding to competition for the small amount of remaining habitat.
The Northern Tallgrass Prairie National Wildlife Refuge was established in 2000 to address the loss of these American grasslands and the declining species that depend on them. Refuge management focuses on connecting scattered remnant prairies in western Minnesota and Iowa and restoring ecosystem functions. The refuge provides a place for groups with similar goals to work together to conserve and restore northern tallgrass prairie.
Lands proposed for inclusion in the refuge contain native grasslands that, in many cases, are the only remaining cover available to wildlife in a predominantly agricultural landscape. Incredibly, these remnant tracts support more than 300 plant species and 1,500 insect species. Wildlife associated with these small, scattered tracts include upland sandpiper, marbled godwit, sandhill crane, and prairie chicken. Approximately 243 species of birds are known to regularly use the northern tallgrass prairie area at some time of the year, with 152 species breeding here.
Although limited to small, scattered tracts of remnant prairie, the Northern Tallgrass Prairie National Wildlife Refuge supports a surprising diversity of life. Four plant species and seven wildlife species found in the refuge are federally endangered or threatened, including two of the world’s largest populations of the threatened prairie bush clover, as well as the federally threatened western prairie fringed orchid and piping plover. The refuge contains indispensable habitat for waterfowl such as mallards, pintail, canvasback and blue-winged teal.
Several globally rare species can be found here, including some of the last remaining populations of the rare Dakota skipper, powesheik skipperling, and regal fritillary butterflies.
Remaining tallgrass prairie in Minnesota and Iowa is continually threatened by lack of fire, intensive grazing systems, gravel mining, conversion to agricultural row crops, and invasive nonnative species. Protection through acquisition or easement prevents conversion and allows management in the form of prescribed fire, rotational grazing where appropriate, and restoration of old cropland using local ecotype grass and forb seed.
In the long term, refuge staff hope to reconstruct tallgrass prairie using native plant species to buffer or connect remnant native prairie tracts, which are severely threatened by fragmentation. During poor economies, financially stressed farmers often consider dividing and selling portions of their land. Easements can provide financial assistance to help them keep their property and prevent further subdivision. Prairies are a well-documented store of terrestrial carbon. Preventing conversion with grassland easements ensures this carbon will be maintained.
The Northern Tallgrass Prairie National Wildlife Refuge, by preserving and restoring remnant prairie, is preventing the extinction of an ecosystem and helping to conserve and recover many rare and declining species.
For information on endangered species work in the Midwest, visit www.fws.gov/midwest/endangered