Greater Protections Needed in America’s Heartland
• More than 97% of the native grasslands of the U.S. have been lost, mostly because of conversion to agriculture. As a result, grassland bird populations have declined from historic levels far more than any other group of birds.
• Although only 13% of remaining grassland is publicly owned, public lands support 17% of the U.S. distribution of breeding and 20% of
wintering grassland-dependent birds, indicating the value of public grasslands to birds.
• Forty-four percent of the U.S. winter distribution of Baird’s Sparrow (a species of conservation concern) is on public land.
• More public grasslands specifically protected for birds and other wildlife are needed. Grassland bird conservation should be a higher priority on public grasslands with multiple uses.
• Acquisition and restoration of native grasslands are critical to provide larger habitat patches and movement corridors for bird population sustainability, especially in the face of climate change.
|Image: Cimarron National Grassland, Kansas, by Gerrit Vyn|
Grassland Birds on Public Lands
Grassland birds are among the most consistently declining species in the United States. Forty-eight percent of grassland-breeding bird species are of conservation concern, including four with endangered populations. More than 11% of the contiguous 48 states is native grassland, with an additional 7% in pastures and hayfields. Of these 366 million acres of native grasslands, pastures, and hayfields, only 13% is publicly owned. Of the 36 obligate grassland bird species (20 in both seasons, 9 species only during the breeding season, and 7 only
in winter), 17% of their distribution during the breeding season and 20% during winter are found on public lands, indicating the value of public grasslands to birds.
Six grassland species have more than 30% of their U.S. distribution on public lands in winter: Baird’s Sparrow, Ferruginous Hawk, Lark Bunting, Rough-legged Hawk, McCown’s Longspur, and Western Meadowlark. All except Baird’s Sparrow use BLM lands more than any other public land. All of these birds are western species, reflecting greater public ownership in the West compared with the East.
Only three grassland species have more than 30% of their
distribution on public lands during the breeding season: Long-billed
Curlew, Ferruginous Hawk, and Mountain Plover. These western birds
inhabit BLM lands more than any other lands managed by a single
Four grassland species have 5% or less of their distribution on public lands: breeding Dickcissels, Scissor-tailed Flycatchers, and Eastern Meadowlarks, and wintering Harris’s Sparrows. All of these are predominantly found in the Midwest, in states with much less public land compared with those farther west.
We have not included row-crop agricultural lands in this report because although they cover almost as much acreage as grasslands, only 3% of rowcrop land is publicly owned. In addition, rowcrop lands provide little quality habitat for birds. However, a few grassland birds breed in row-crop fields, and many more winter in them.
Ferruginous Hawk, one of three breeding species with more than 30% of its distribution on public lands, is one of the few grassland species with an increasing population trend over the past 40 years.
The Bartel Grassland Restoration Project has successfully restored grassland birds on Cook County public lands near Chicago, Illinois. Invasive trees, such as box elder and buckthorn, were removed from the site. Soon after, birds such as Grasshopper and Henslow’s sparrows, meadowlarks, Bobolink, and Short-eared Owl increased. When complete, the site will include 900 acres of restored grassland and wetlands.
|Percentage of the U.S. distribution of 29 grassland-breeding bird species on public vs. nonpublic lands (left). Breakdown of bird distribution on public lands shown for each public agency (right).|
|Western Meadowlark by Gerrit Vyn|
Only 13% of U.S. grassland is publicly owned, less than 14% of which is protected to maintain natural habitats. Thus, less than 2% is both publicly owned and managed primarily for conservation. Sixty-three percent of publicly owned grassland is protected from conversion to other uses, but is subject to multiple-use demands, and the remaining 22% is unprotected from development or conversion. Fortunately, grassland birds can coexist with other uses, such as livestock grazing, if habitat is managed with birds in mind. For example, grazing animals and grassland birds are both threatened by invasive plants that diminish the quality of grassland, so livestock owners and conservationists share an interest in combating invasive plants. Management practices such as burning, grazing, and mechanical intervention to resist invasion by woody plants can benefit both livestock and birds.
Proper siting of energy development projects on public lands is critically important to grassland birds, including gas, oil, solar, and wind, as well as roads and transmission lines required to deliver power from the source to the end-user. These projects cause habitat loss and degradation; in addition, many grassland bird species have been shown to avoid areas near tall structures in otherwise suitable habitat.
Grassland has always been undervalued as wildlife habitat. The percentage of grassland birds on public lands is low because such a small amount of U.S. grassland (less than 2%) is both publicly owned and managed primarily for conservation. More public land specifically protected for grassland birds is needed, and a higher proportion of multiple-use lands should be managed with grassland birds in mind.