Bird Conservation in America’s Heartland
Robert P. Ford
Ever hear of the Interior Low Plateau Region? If not, you may be surprised that it covers over 30 million acres (12.1 million hectares), spread across a wide swath of the south-central United States from southern Illinois, Indiana and Ohio, through Kentucky and Tennessee, and into northern Alabama. It is a haven for hundreds of species of wild birds and a region of progressive bird conservation activities.
The marked diversity of habitats in the Interior Low Plateau reflect a long and varied history of climatic and geological influences. Grassland and oak savanna communities characteristic of the Great Plains are found here. Extensive western mesophytic (oak-hickory) forests and forested wetlands also occur throughout the region. The rare barren and glade habitat types–recognized as communities of global ecological importance–are scattered in pockets among the taller, dominant forests. Geographers have done their part by coining colorful names for the corresponding physiographic subdivisions: the Bluegrass and Pennyroyal Regions of Kentucky, the Western Highland Rim of Tennessee, and the Tennessee Valley of northern Alabama.
This is a place where rich American folklore originated. It’s also a place where new ways of approaching bird conservation are springing to life. While few threatened or endangered bird species occur within the Interior Low Plateau, many bird species in many different habitats within this region are experiencing long-term declines.
For example, the cerulean warbler (Dendroica cerulea), considered a common species throughout the region only 30 years ago, is now uncommon in some parts and rare in many others. Cerulean warblers occur in large tracts of mature hardwoods during the summer and in the Peruvian montane forests of South America during the winter. Why it is declining at rates exceeding 3 percent per year is not known for sure, but other species that share its breeding habitat, like the wood thrush (Hylocichla mustelina), yellow-billed cuckoo (Coccyzus americanus), and Louisiana waterthrush (Seiurus motacilla), are declining as well.
Bewick’s wren (Thryomanes bewickii), still fairly common in the western United States, has almost disappeared from the East. This wren’s favorite haunts include slash piles in forest industry clearcuts, areas of natural disturbance, rural areas, and old farms. It, too, is not alone in its population decline: the Bachman’s sparrow (Aimophila aestivalis), northern bobwhite (Colinus virginianus), and field sparrow (Spizella pusilla) also are disappearing from rural landscapes.
The Henslow’s sparrow (Ammodramus henslowii) occurs in large grasslands, and although it is expanding its range in the Interior Low Plateau Region, overall population numbers are very low. The grassland-dwelling dickcissel (Spiza americana) and grasshopper sparrow (Ammodramus savannarum) are declining, too. Although no species are entirely dependent on barrens and glade habitats, two declining species, the prairie and blue-winged warbler (Dendroica discolor and Vermivora pinus, respectively), are regularly found there.
How have we responded to these declines? Under the umbrella of the Partners in Flight program, diverse, and some historically unusual, partnerships have formed to halt and reverse declining populations through better habitat management and research. A team comprised of the forest products industry (Westvaco Corporation, Champion International, Willamette Industries), State fish and wildlife agencies, U.S. Fish and Wildlife Service, Tennessee Valley Authority, Tennessee Conservation League, The Nature Conservancy, and numerous other businesses, universities, and private landowners are bringing their collective resources to bear on these populations and habitats.
A Partners in Flight Bird Conservation Plan has been drafted for the Interior Low Plateau Region. This novel plan promotes landscape-level habitat conservation and management that encourages not only biological sustainability, but economic sustainability as well. Scientific research plays a major role in this plan. For example, analysis of Breeding Bird Atlas data has provided locations of important areas for entire suites of species, such as cerulean warblers and wood thrush, that depend upon mature hardwoods. Current field work is building upon those data to determine which of these areas have the best chance of sustaining these populations. Combining solid scientific information with open communication among partners is proving to be a strong force for future management of critically important habitats. Traditional adversaries are now working together for common goals.
The forest products industry has been an important partner in sustaining mature hardwoods within a managed forested landscape. Industry is now considering ways to improve habitat conditions on clearcuts to provide habitat for Bewick’s wren and Bachman’s sparrow. In grassland habitats, Partners in Flight objectives have been linked with State agency small game objectives for warm season grass restoration and management. All of the animals benefit. Finally, in barrens and glade habitats, bird population objectives established by Partners in Flight are closely tied to experimental management efforts that are aimed at restoring the natural features of these barrens. As research determines bird responses to different restoration techniques, further population and management objectives will be set across the Interior Low Plateau.
Many management questions remain in the region. For example, how much acreage in mature forest do cerulean warblers need to maintain healthy populations? How does the nesting productivity of Bewick’s wren and Bachman’s sparrow in clearcuts compare to productivity in more stable early-succession habitats, such as barrens and glades? How large do grasslands need to be in the Interior Low Plateau in order to sustain Henslow’s sparrow populations? These are all critical parts of the conservation puzzle yet to be solved.
Conservation and management of wild birds within the Interior Low Plateau will move forward with advances in research and monitoring. This strategy is in step with the progressive new way of thinking in this otherwise traditional region.
Bob Ford works for the Tennessee Conservation League, an affiliate of the National Wildlife Federation, and is the Director of the Lucius Burch Center for Conservation Planning.
COPYRIGHT 1998 U.S. Fish & Wildlife Service
COPYRIGHT 2004 Gale Group