More than 600 bison are being held in capture facilities north of Yellowstone National Park, including 62 that were captured Wednesday.
For a month, the bison have been devouring as much as 5 to 6 tons of hay a day, Yellowstone spokesman Al Nash said.
The hay comes from the park’s stockpile of 310 tons that is used for stock during the summer. Park officials are concerned that feeding the animals may habituate them to return to the area in future winters.
“We certainly have those concerns,” Nash said. “Our preference is not to manage wildlife any more than is necessary, whether it’s bison or any other species in the park, unless it’s an issue involving an experimental population, an endangered species or a non-native species.”
In 2008, more than 1,400 bison were killed, with the meat distributed to tribes and food banks. The bison tend to migrate when the herd tops 3,000 animals.
This year, the park’s bison population was estimated at 3,900.
The slaughter option was taken off the table this year when Gov. Brian Schweitzer issued a 90-day moratorium on shipment of bison to slaughter in Montana.
There is no other route for the Park Service to move the bison, since commercial trucking is not allowed inside the park.
The moratorium won’t expire until May.
Before then, park officials could haze bison back into the park if there is sufficient natural food, which is dependent on the weather.
Nash said it’s still undecided whether the 40 percent of the more than 600 bison that tested positive for exposure to brucellosis would be allowed to return to the park.
“We haven’t made any decisions,” he said.