The Nature Conservanay's Bison Herd Expands Onto New Prairie and Soon With New Calves

Published on Wed, 03/11/2009 - 9:54am

DES MOINES, Iowa – The historically and genetically valuable bison at The Nature Conservancy’s Broken Kettle Grasslands Preserve will graze another 275 acres as one more gate is opened for the new herd on Iowa’s largest contiguous native prairie. The 28 bison, moved to Broken Kettle in October 2008, has spent most of the winter on more than 150 acres. Opening the gate will give the small herd access to 500 acres and less viewing possibilities by the public as they are able to go farther back on the Conservancy property.

“We have had snow on the ground since mid-December and they have done really well. We stopped breaking up ice when it became obvious that they were not using the water provided but eating the snow. The calves from the fall look great and the cows are fat. We expect new calves in mid to late April,” said Scott Moats, the Conservancy’s Broken Kettle Grasslands preserve manager. “I have been surprised at how content this herd has been with very little management. We have only provided mineral supplement.

Acclimating bison to new pastures is accomplished by opening new sections and then removing interior fencing. The capacity of bison at Broken Kettle will be 250 adult bison on 2,500 acres. The Conservancy expects to reach that goal by October 2014.

“We expect that the herd will cover every corner of their current pasture, creating an interesting mosaic of grazing pattern, which will result in good ecological benefits. Unfortunately for our neighbors and the interested public, the larger pasture will mean that for now, they’ll be more difficult to see from the road,” said Moats. “Eventually, the herd will have access to areas that will be easily seen from the scenic overlook on Butcher Road.

Moats expects 8-10 calves this spring. The bison herd has 12 mature cows, with an expectation that 70-75 percent are bred. The herd came from the Conservancy’s Lame Johnny Creek Ranch in South Dakota but originated from the Wind Cave National Park herd. They are considered historically and genetically valuable because they have shown no evidence of cattle introgression or cattle genes as determined by current DNA testing techniques. Almost all bison herds, except those at Wind Cave National Park and Yellowstone National Park contain evidence of cattle genes. The Conservancy is working closely with Texas A&M University to determine the best course of action to conserve the genetic integrity and diversity of these unique bison at Broken Kettle Grasslands.

And while the Conservancy conserves and protects the bison, the bison will benefit the prairie. Bison grazing provides a “disturbance” which allows for a more diverse mix of prairie species and a diverse structure critical for the survival of the animals dependent on prairie habitat.

Large-scale prairie restoration efforts are working in Iowa. The arrival of these big, native grass-eaters is an exciting step in the long term goals for Iowa’s largest remaining prairie.

Broken Kettle Grasslands is located in the northern portion of the Loess Hills, which rise 200 feet above the Missouri River Valley, snaking in a narrow band of wrinkled bluffs that cover some 650,000 acres along the state’s western border. It is 25 minutes northwest of Sioux City, Iowa. This region supports some of Iowa’s best examples of tallgrass prairie.

The extensive prairie ridgetops at Broken Kettle Grasslands feature a variety of plants and animals typically found further west in the Great Plains, like the yucca plant and the prairie rattlesnake. Broken Kettle also harbors many plant species, including lead plant, big bluestem, silky aster, ground plum, side-oats gramma, downy painted cup, purple coneflower, snow-on-the-mountain, scarlet gaura, dotted blazing star, purple locoweed, pasque flower, bur oak, little bluestem, buffalo berry and scarlet globe mallow. Animal life includes the black-billed magpie, bobolink, grasshopper sparrow, western kingbird and the Great Plains toad.

Grasslands of all kinds once covered 40 percent of the Earth’s land masses. But today, they are the least protected, most threatened terrestrial habitat on Earth. In fact, almost half of grasslands worldwide have been altered and the remaining landscapes face new and unprecedented threats. More than 800 million people live in the world’s grasslands, and most of them have a serious stake in the future of these places. With so many lives dependent on healthy, productive grasslands, their protection is integral to maintaining human well-being and biodiversity around the world.

The Nature Conservancy is the leading conservation organization working to protect the most ecologically important lands and waters around the world for nature and people. To date, the Conservancy and its more than one million members have been responsible for the protection of more than 15 million acres in the United States and have helped preserve more than 102 million acres in Latin America, the Caribbean, Asia and the Pacific. Visit The Nature Conservancy on the Web at

The Nature Conservancy in Iowa has more than 7,500 members and manages 33 preserves totaling over 6,000 acres. Since the Chapter began in 1963, with the aid of volunteers it has been involved in the protection of nearly 20,000 acres in the state, including native prairies, wetlands and woodland communities.

If you would rather not receive future email messages from The Nature Conservancy, let us know by clicking here.
The Nature Conservancy, 4245 Fairfax Dr, Arlington, VA 22203 United States