Hundreds of bison migrating from America’s Yellowstone National Park are set to be killed because of fears they could spread disease.
Montana governor Steve Bullock had blocked the plan to cull up to 1,300 of the park’s 5,500 bison this winter.
But after two weeks of intensive negotiations a deal has been struck between Montana, Yellowstone and the Department of Agriculture.
Officials say it is necessary to stop them spreading brucellosis to cattle as they head out on their annual migration.
The disease can cause animals to abort their young and has been eradicated in the US, apart from in Yellowstone.
However, researchers and livestock officials say no transmissions of the disease from bison to cattle have been recorded.
That is partly because more than 5,000 have been killed of captured trying to leave the park since 1985.
Wildlife campaigners strongly oppose the periodic culls.
“Stop the slaughter, let them roam and manage them just like we do with elk, just like we do with deer, just like we do with other wildlife,” said Stephany Seay from the Buffalo Field Campaign.
Some 25 bison will be spared so that Native American tribes can start new herds elsewhere.
They will be kept for a year in quarantine just north of the park in Corwin Springs, before being moved to Fort Peck, home of the Assiniboine and Sioux tribes.
Wildlife officials say hunters have killed more than 300 bison so far this winter as they left the park to search for food.
About 400 have also been captured trying to migrate and will be slaughtered. Meat from the animals is given to Native American tribes in the region.
An agreement in 2000 set a population goal of 3,000 bison in the park.
Yellowstone is renowned for its wildlife and spurting geysers such as Old Faithful, and spans nearly 3,500 square miles across Montana, Wyoming and Idaho.