Where the bison roam

LUVERNE -- Two cows and two heifer calves from Blue Mounds State Park's bison herd left Rock County Wednesday morning for their new home at the Minnesota Zoo in Apple Valley. They will be part of an existing bison and pronghorn antelope exhibit at the zoo following a 60-day mandatory quarantine.

Craig Beckman, Blue Mounds State Park manager, said the transfer of the four bison is the result of a recent agreement between the Minnesota Department of Natural Resources (DNR) and the Minnesota Zoo to work on managing a pure genetic line of bison.

It was a year ago that Blue Mounds conducted genetic testing on 26 of the bison in its herd. Through blood and hair sample collections, which were studied by researchers at Texas A&M University, it was learned just one of the bison cows tested from Blue Mounds had a trace of cattle genetics in her.

Cattle genetics are found in many of the bison herds remaining in the U.S. today, said Beckman. An ongoing bison project is working to map the bison genome.

Though staff at the Blue Mounds didn't have high expectations when they conducted the first genetic testing in the herd last year, Beckman said they were all "shocked" when the testing results came back.

At one time, North America was home to 30 to 60 million bison, but as settlers moved west and hunting took its toll, the estimated number of bison had dwindled to less than 1,000 by the late 1880s.

"To recover, they were bred with cattle," Beckman said. "Many (herds) in the U.S. today have cattle genetics mixed with them."

Blue Mounds is one of a few state parks across the country to still have what are considered mostly pure bloodlines in its bison herd.

The genetic discovery is what spurred the partnership with the Minnesota Zoo. It is also what has led to a shift in focus at the Blue Mounds in how the herd is groomed for the future.

Bison auction

The park will conduct its annual bison auction at 10 a.m. Friday, selling 25 animals from its herd.

"The animals at auction are fine," Beckman said. "We've always made educated decisions ... based on age structure. Now, it's really based more on the genetic makeup of the animal. Every animal we're selling this year is for a specific management reason to better the genetic makeup and diversity of our herd."

The auction typically draws 20 to 25 bidders, although Beckman said only about a handful of bidders end up purchasing the majority of the bison. Some will be processed for meat, while others will be added to private herds.

On the auction block are five yearling heifers, 10 yearling bulls, two adult cows (age 5 and older), five 2- to 3-year-old bulls and an 11-year-old bull that recently lost his rank as the herd bull. That particular animal weighs more than a ton.

Beckman said there are a number of bulls on the auction this year because Blue Mounds will be introducing two bulls from Oklahoma's Wichita Mountains Wildlife Refuge. Those bulls are also part of a "very pure line" of bison with lineage that isn't well represented in this area.

"When the new Oklahoma bulls come in, we want as limited competition for those bulls as we can get," he added.

Further testing

On Tuesday, Beckman was joined by three staffers from the Minnesota Zoo and a veterinarian from the Rock County Veterinary Clinic as another 40 bison were moved through the state park's corral. Hair and blood samples were taken from each animal for further genetic testing.

"We should have around 65 animals -- after this year -- that have been tested," Beckman said. "Statistically we will have a very accurate idea of the genetic makeup of our herd."

To know that the bison at Blue Mounds State Park have a genetic link to the 30 to 60 million bison that once roamed the prairies centuries ago is rather amazing.

"To recover the way it has today just speaks volumes of the strength of that species," Beckman said.

At Blue Mounds, the bison are part of the overall management program of the state park's native prairie. The park has a carrying capacity of approximately 70 grassfed bison.

Beckman said the goal is to keep the herd at a level so that the prairie doesn't look like a cattle pasture, where grasses are just inches high, but to maintain the appearance of the tall-grass prairie.

Life at the zoo

The four bison taken to the Minnesota Zoo will join two other bison already in the exhibit, along with a bull acquired from Badlands National Park. That bull also stems from a very pure line of bison.

Tony Fisher, collections manager at the Minnesota Zoo, said the bison exhibit has been in existence since the zoo opened.

"Our herd was getting old, we were down to just a couple of animals left," he said Wednesday afternoon. "It was time to start a new herd."

Offspring from the new animals will be distributed back to the Minnesota DNR, and may end up returning to Blue Mounds State Park.

"We're pretty excited to participate with the DNR in this conservation work at home," Fisher said. "We do so much with conservation (efforts) around the world, to be a part of conservation right here in Minnesota, it's really rewarding for us, and it's a nice partnership with the DNR."

Eventually, the bison on display at the Minnesota Zoo will include a graphic display highlighting their origination from Blue Mounds State Park.

Daily Globe Reporter Julie Buntjer may be reached at 376-7330.