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Bison herd of Sandhill Wildlife Area

A herd of about 15 bison lives in a 260-acre enclosure along the Trumpeter Trail. Current management attempts to restore native prairie and oak savanna habitats within this enclosure. Bison were once found in southeastern Wisconsin, but early-day traders and Native Americans extirpated them from the state before the first settlers arrived in the 1830s.

In the late 1940s, the property's then-owner, Wallace Grange, acquired several bison, and their descendants thrive here today.

Bison in Wisconsin?

Although bison are usually associated with the western plains, herds once ranged from Georgia to the Hudson Bay and from the Appalachians to the Rockies. Bison were prevalent in the original prairie and savanna communities in southern and western Wisconsin. Bison likely wandered into the oak barrens of Wood County. The Sandhill bison herd that now roams two enclosed pastures on the property began when Wallace Grange acquired a heifer calf in 1946. After maturing, this heifer mated with a bull purchased in 1949. When the state purchased Sandhill Game Farm in 1962, Grange donated his herd of 12 bison.

Buffalo or bison?

The American bison is in fact not a buffalo. Our bison is related to the European bison or wisent, which migrated to North America from Asia. It is not related to the hard-working water buffalo of Asia or the ferocious Cape buffalo of Africa. Early settlers called these animals "buffalo," and they have been called buffalo by Americans ever since.

Back from the brink

The restoration of bison from near extinction is one of the most dramatic conservation stories of this century. A combination of ranching, habitat destruction and market hunting quickly reduced the bison population from 60-70 million in the late 1700s to only 800 by 1890. This destruction took less than 100 years. The last two bison east of the Mississippi River was shot in Wisconsin in 1832. Fortunately, during the time wild bison herds were being destroyed, a number of people were developing small captive herds. Bison now seen in national wildlife refuges and in parks came largely from three of these captive herds. Today, the success of that effort is reflected in over 75,000 bison now roaming both public and private lands in the United States.

Bison biology

The bison is the largest land animal in North America. It normally lives 15 to 20 years but can live up to 40 years. Both cows and bulls have sharp, curved horns. Bulls can reach a weight of 2,000 pounds or more, and cows can weigh 1,300 pounds. Bison reach maturity around 7 to 8 years of age. Despite appearances, the bison is a deceptively quick and agile animal and can gallop up to 35 miles per hour over rough terrain. The bison is quite hardy and can survive extreme weather conditions where other large animals would perish.

The breeding season for bison is in July and August. Their gestation period (pregnancy) varies from 270 to 285 days, with most calves being born in May. Normally, a cow will give birth to a single calf. Twinning is rare but possible. Calves vary in color from red to cinnamon at birth and show no sign of the characteristic hump until about 2 months of age.

The bison begin to shed their heavy winter coats in the spring. To hasten the shedding and relieve itching, they often rub against large stones and trees. Travelers in the 1880s wrote of seeing highly polished stones and trees with the bark rubbed off 6 to 7 feet above the ground. Without the protection of their coats, the animals are especially vulnerable to insect attacks in the summer. To escape their tormentors, bison wallow in dust or sand. Early travelers on the plains wrote of buffalo wallows that were often a foot or more deep and 15 feet across. Similar wallows can be seen in the Sandhill bison range.

Bison habitat at Sandhill

Frequent visitors to Sandhill have probably noticed some recent changes to the bison area. Our main management goal for the bison pasture is to restore the area to the native oak savanna. Oak savanna is an open landscape dominated by prairie plants with scattered oak trees.

Today, oak savannas and open prairie are a rare sight in Wisconsin along with the animals that use them. The endangered Karner blue butterfly is one such animal that is found in the bison pasture. Our habitat restoration efforts benefit this small blue butterfly, which depends on the wild lupine plant for nectar and a place to lay eggs. The lupine plant has purple pea-like flowers that bloom from May through July. The Karner blue butterfly requires large patches of this plant for its continued survival. Habitat restoration is very time-consuming and very costly. However, by creating an open savanna, we will increase the chance of seeing bison in their native habitat, improve range conditions, provide educational opportunities for school groups and individuals and provide a home for other rare species of wildlife, including the Karner blue butterfly.

Finally, we are undertaking this effort to conserve the bison itself, a magnificent animal so symbolic of the early frontier. We have established a gift account for the Sandhill Wildlife Area. Money donated to this account goes directly to habitat restoration efforts. This money will be used for projects like the oak savanna restoration, which might not otherwise be possible. If you would like to make a contribution, please use the donation box in our office during normal business hours or contact us at the following address: Sandhill Wildlife Area, PO Box 156, Babcock, WI 54413-0156.