The Northern Great Plains region, covering parts of South Dakota, through Montana, up to Saskatchewan and Alberta in Canada, was historically rich with grasslands and shrub steppe, and home to many large, spectacular herds of bison and pronghorn, who grazed and shaped the vegetation of this ecosystem. The Great Plains was also prime habitat for grassland birds, a set of species that today are in decline due to the past century of habitat conversion, degradation, and fragmentation. With their songs and colors, grassland birds enliven the vast Great Plains. Grassland bird species need vast treeless areas, as nearly all nest on the ground, hiding their young in the sea of grass and wildflowers. In North America, forty-two bird species depend on grasslands for breeding. Nine species (mountain plover, long-billed curlew, ferruginous hawk, McCown’s and chestnut-collared longspurs, lark bunting, Baird’s and Cassin’s sparrows, and Sprague’s pipit) are endemic, or unique, to the northern Great Plains. Grassland birds are among the most imperiled types of birds in the world.
In North America, grasslands are the most endangered ecosystem. Gone are the once vast horizons of contiguous grasslands that supported an abundance of wildlife. Over the past century, the grazing of domestic stock, both bison and cattle, has been managed to homogenize grasslands. An associated impact has been dramatic declines in grassland bird species that rely on a shifting mosaic of diverse vegetation structures, ranging from tall, ungrazed native grasses or short, nearly barren ground. As the primary herbivore in the plains, bison helped shape the ecosystem. Several bird species adapted to or co-evolved with types of grasses and vegetation structures that had been, for millennia, grazed by millions of free-ranging bison. They were part of a functioning Great Plains that included millions of prairie dogs and pronghorn as well, and healthy populations of native carnivores. Today, much of the Great Plains lack the primary forces of bison grazing, prairie dog burrowing, and seasonal, natural fires. Further, many grassland habitats are additionally degraded due to overgrazing by cattle.
WCS is investigating the best ways to conserve grassland birds by restoring their habitat through bison grazing and other activities that mimic natural bison grazing. As bison herds dot the Great Plains, both on private and public land, there is an opportunity to see how bison behavior – quite different than cattle behavior – can help keep grasslands healthy, control invasive species, and create seasonal variety in grass height. Over an area of 450,000 acres, we are working on solutions to grassland degradation with a broad range of partners, monitoring bird populations and bird-bison habitat associations, and developing science-based guidelines for how to manage grazing so that it creates more bird habitat.
- identifying grassland features that benefit birds;
- guiding management so that it provides more suitable habitat for each species;
- coordinating when, where, and how grasslands are grazed and/or burned to coincide with bird species preferences for different grass heights and density;
- assisting land managers on how to best use bison grazing to manage for wildlife;
- Studying and how, where, and when grassland birds migrate to the southern Plains;
- Identifying how grassland conservation can be best incorporated into ranching livelihoods.