Bison Return to the Native Prairie at Broken Kettle Grasslands

By Guest Contributor

First posted on 11-04-2008

The Nature Conservancy in Iowa announces that 28 bison have arrived at Broken Kettle Grassland Preserve in the globally rare Loess Hills in western Iowa late Monday afternoon. Of the 28 bison, seven are calves, five are bulls and 16 are cows. Broken Kettle Grasslands is the largest contiguous native prairie in the state.

These bison came from the Conservancy’s Lame Johnny Creek Ranch, in South Dakota. The herd originated from the Wind Cave National Park herd and is historically and genetically valuable. They have to date shown no evidence of cattle introgression or cattle genes as determined by current DNA testing techniques. This starter herd is a maternal grouping — bison that have group dynamics figured out and stick together.

More than 150 years ago, bison were a natural and integral part of the prairie ecosystem before Europeans settled the vast central tallgrass 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.

“Bison provide a different effect on the ground. We expect a more wide-spread disturbance pattern with better pasture utilization,” said Scott Moats, the Conservancy’s Broken Kettle Grasslands preserve manager. “With bison, we’ll see a change in the plant community. Our prairie is ready for them.”

And while the bison will benefit the prairie, the Conservancy is working closely with Texas A&M University to determine the best course of action to conserve the genetic integrity of these unique bison at Broken Kettle Grasslands.

The herd arrived at Broken Kettle Grasslands at 5:30 p.m. on Monday, October 20. Moats and his crew immediately unloaded the 28 bison from the specifically designed bison transport truck. The bison will be held until next Monday, October 27, in the corral with native prairie hay and water provided until they acclimate to their current environment. From there, they will be released into the west half of the trap pasture. They will have access to the entire 125-acre trap pasture for winter. In the trap pasture, supplemental feed and water will be provided. Once the bison are released in the spring, natural water sources and native prairie will support the needs of the bison.

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. Today, less than one percent of the original tallgrass prairie remains; making it one of North America’s most endangered ecosystems.