The US Interior Department is asking a federal judge in Montana not to intervene in the impending slaughter of potentially hundreds of wild bison that were captured after migrating out of Yellowstone National Park.
In a court document, lawyers for the agency said stopping the slaughter would allow bison to enter parts of Montana, where they could spread the disease brucellosis to livestock.
They agency also says the "massive wild animals" could cause property damage, compete with livestock for grazing and destroy crops.
Almost 400 bison are being held in corrals along the park's northern border. Animals testing positive for exposure to brucellosis face shipment to slaughter.
Wildlife advocates last week asked US District Judge Charles Lovell to block those shipments, saying bison could be safely managed outside the park.