Top Questions about the Project from the Nachusa Grasslands Why are bison important to Nachusa and why are they being reintroduced at this time? Bison are the critical missing piece of a full prairie system ecology. Their selective eating of grasses will benefit our forb propagation. The building of wallows, impact of their hooves and spreading of dung will also reflect the way the natural ecosystem worked hundreds of years ago. Nachusa is one of the Eastern-most preserves where the rein- troduction of bison on our type of prairie has not occurred. Many scientists are studying the influence of bison on Nachusa at this time. You will see a series of “exclosures” – small areas that have been fenced out in the prairie. These will allow scientists to determine the bison’s impact by comparing species diversification and growth in the areas from which bison have been excluded. Where did Nachusa get its bison? All of Nachusa’s bison originated from the Wind Cave bison herd located in Wind Cave National Park in South Dakota. This herd is supported by several of The Nature Conservancy preserves, which are collectively working together to grow the overall herd to a minimum of 1,000 animals. Currently, the park has approximately 500 animals and TNC’s preserves have another 350 animals. This herd is very important for conservation of the bison as a spe- cies. Wind Cave National Park and Yellowstone National Park have the only two herds that have been shown to have the least amount of cattle introgression. In the early 1900s when bison were almost slaughtered to extinction, many of the few remaining animals were bred with cattle. Wind Cave and Yellowstone bison were protected and not inter- bred. Extensive DNA testing has proven that these herds are of significant genetic conservation value. Nachusa’s bison were obtained from the Lame Johnny Creek Preserve in South Dakota, the Broken Kettle Preserve in Iowa and the Dunn Ranch in Missouri. In the fall of 2015, 12 additional animals from Wind Cave National Park will be brought to Nachusa. How many animals do you now have, and what are their genders and age ranges? We currently have 30 bison, which have come from other TNC preserves. All of our bison originated from a single herd at the Wind Cave National Park in South Dakota. The herd consists of 18 cows, 2 mature bulls, 2 middle-aged bulls, five yearling bulls, and three calves. Our current herd’s ages range from calves that were born in June 2014 to mature bulls that are 6½ years old to 2 cows that are 11 years old. Diverse age and maternal groups are ideal in starting a bison herd, so the Nachusa staff worked very hard to secure our founding herd to meet this criteria How many total animals do you anticipate getting? We anticipate getting an additional 12 animals as part of our program next year. We will need to determine how many animals can be supported by the vegetation available. When the south unit is operational, we may be able to support between 100 and 150 bison. Can bison get through Nachusa’s fence? It is possible that, if a bison is frightened or cornered, it could break down our fence. This is the same fence that was recommended and used extensively by other preserves and has been found to be effective. It is also possible that a gate could accidentally be left open – we certainly will avoid that, and all stewards must be vigilant in clos- ing and locking gates when they enter and leave a bison unit. If bison escape, they will be carefully herded back inside the fence. Fortunately, bison desire to be with the herd, so we are anticipating that they will naturally want to get back with the herd should they escape.
January, February & March 2015 Crest Ink 23
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