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The bison herd at The Nature Conservancy’s Broken Kettle Grasslands Preserve in the globally rare Loess Hills in Western Iowa is a little larger today thanks to the arrival of its first calf. This is the first time that a bison has been born on native prairie in Iowa in more than a century and a half within a herd established exclusively for conservation.

“It’s really exciting and it tells me a lot about the condition of both the prairie and the herd,” said Scott Moats, manager of the Conservancy’s Broken Kettle Grasslands Preserve. “We moved them from South Dakota last year and we had a pretty tough winter here in Iowa. That they’re able to calve tells me the forage is adequate and everything they need is here. They should be able to thrive and do what we want them to do ecologically.”

Moats said that the calf was first observed on Saturday but that its precise date of birth was unclear. “We had a cow disappear on Friday. They typically take off and calve on their own. She returned to the herd Saturday afternoon with her calf.”

Moats said the calf’s gender will not be known until fall when the herd will be rounded up at Broken Kettle for the first time; however, the calf appears to be in excellent health. “It’s a pretty thick little calf and it’s really mobile. It’s moving around the pasture and following the herd. The cow is nursing. We’ll let them do their thing.”

Sean McMahon, director of The Nature Conservancy in Iowa, said that by establishing a genetically valuable herd at Broken Kettle, the Conservancy is helping conserve an iconic species of wildlife and improving the state’s largest contiguous native prairie.

“Bison provide a crucial grazing ‘disturbance’ that creates a healthier and more diverse prairie,” McMahon said. “Now that we’ve returned this rare population of bison to Iowa’s premier prairie we expect our native grasses and wildflowers will do even better.”

Moats expects more calves to be born 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.

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 the preserve 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 800million 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 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.