DENVER, Aug. 12 (UPI) -- Descendants of genetically pure Yellowstone National Park bison, part of a herd in northern Colorado, will make their way back to Montana tribal lands by way of the Oakland Zoo.
A small herd that started in 2015 with 10 cows at Colorado State University has grown to 77 animals.
In July, two Colorado-bred bulls were shipped to the zoo's new 13-acre bison habitat overlooking the ocean. Animal scientists hope the bulls will breed with cows from an 1800s herd from Elk Island National Park in Alberta, Canada, said Erin Dogan Harrison, the zoos's communications director.
The plan is part of a program to return heritage bison to tribal lands, specifically the Blackfeet Nation in northwest Montana.
The Blackfeet Nation's Iinnii Initiative brought a herd of 89 Elk Island Park bison back to tribal lands in 2018. Four Canadian and U.S. tribes comprising the Blackfeet Confederacy, the Siksika, the Kainai, the Piegan and Blackfeet, worked together to bring bison back to tribal property near Browning, Mont.
The herd is like a living inspiration for members of the Blackfeet Nation, said Teri Loring Dahle, who helped coordinate the project.
"Iinnii is a Blackfeet word that means 'taking hardships away.' When we see the buffalo, it means the Creator gave us everything we need in the form of this animal," she said.
"These animals are culturally and spiritually connected to our people, and I believe their homecoming will begin a healing of historical trauma to the Blackfeet people," Ervin Carlson, president of the Intertribal Buffalo Council, said in a press release.
"These buffalo will begin the longstanding efforts to restore buffalo to their historical mountain-front rangelands."
The Colorado buffalo are descendants of a wild herd that survived at Yellowstone in the early 1900s with help of conservationists and at the urging of President Theodore Roosevelt.
After being almost slaughtered to extinction in the late 1800s and early 1900s, about 500,000 bison now roam the United States. But most have been interbred with cattle and are being raised as livestock. The Yellowstone herd has no cattle DNA, scientists say.
The bison is North America's largest land mammal. Male bulls can reach weights of 2,000 pounds, and adult cows can weigh half that. They live in matriarchal societies and cows may give birth to a single calf every year.
Bison, who in 2016 were designated the national mammal of the United States, are considered a keystone species of the prairie because they grazed and fertilized the grasslands, helping to spread seeds of grasses and other prairie plants. Birds and other grassland animals co-evolved with the bison, scientists say.
The Oakland Zoo also received 20 pregnant females from the Elk Island herd. These bison are descended from animals captured on Blackfeet land in 1873, the zoo's Harrison said.
Breeding the Canadian bison with Yellowstone bison at the zoo will expand the genetic diversity of the tribal herds, she said.
Historically, Yellowstone Park bison were the only surviving U.S. buffalo that never were domesticated, and they have roamed free in the manner they did in prehistoric times.
But the Yellowstone herd has another problem -- up to half of the animals are infected with brucellosis, a livestock disease that causes cows to abort their calves. The disease can spread to cattle, as well as elk.
Ranchers who graze animals on public land nearby fear brucellosis will affect their herds.
For this reason, Yellowstone Park bison have traditionally been culled yearly when they leave the park in winter by the U.S. Department of Agriculture's Wildlife Services Division, a process that has been controversial.
The Colorado bison were raised brucellosis-free, said Jennifer Barfield, assistant professor of veterinary science who is the lead scientist on the project. Some of the Colorado State University bison were bred with animal husbandry techniques and one calf was born through in vitro fertilization.
"It's been a challenge to breed the animals with the Yellowstone genetics who don't have brucellosis," said Barfield, who is a reproductive physiologist. The herd has grown faster than expected on a 2,700-acre parcel at a nearby open space, she said.
The northern Colorado project has also partnered to provide heritage animals to the Pueblo of Pojoaque tribe in New Mexico, which manages bison on the Rio Mora National Wildlife Refuge, in partnership with the Denver Zoo and to the Minnesota Zoo.
In Montana, the Iinnii Initiative herd is a source of pride and a chance to promote eco-tourism at a 9.000-acre buffalo preserve on the Two Medicine River, Dahle said. The program hosts an interpretation center and sponsors school field trips to visit the bison on the range.
"Our whole culture was erased for many generations, and so was the buffalo," Dahle said. "Now we are bringing that spirituality back. My grandmother will be 100 years old in September and she never got to see a buffalo free on the prairie, but her mother did. This herd gives us something to look forward to."
In June, the Blackfeet Nation released a video shot via a drone of the herd after bison wranglers riding horses and all-terrain vehicles moved the animalsto their summer grazing area.
"We're going to keep trucking those offspring and their mothers up to Montana in perpetuity," the Oakland Zoo's Harrison said. "That is the entire idea behind this collaboration, to keep growing these genetically pure healthy herds on tribal land."