A large Yellowstone bison population could mean an increase in hazing operations as the animals seek lower elevation winter habitat in West Yellowstone and Gardiner, Montana  this winter, according to park officials.

In August, wildlife managers counted 4,700 bison in Yellowstone, compared to 3,900 animals counted in August 2006. The bison population hit a record high of 4,900 animals in 2005.

Yellowstone spokesman Al Nash said how and when the bison move depends a lot on the weather. “With the numbers that we have, we’re going to see some animals leave the park,” said Nash. “It’s a question of what weather conditions we may have and whether that will affect bison movements.”

Nash said it’s not necessarily heavy snowfall that would prompt the bison to seek lower elevation habitat. “They are built to deal with a lot of snow,” he said. “It’s very impressive to watch them use that big shoulder muscle and that big head like a plow to clear away deep snow to get at the food underneath.”

However, freezing rain or a thaw followed by a freeze would make it more difficult for bison to get through the snow pack down to forage. “That would be one type of weather incident that certainly could prompt bison to seek forage elsewhere,” said Nash.

Nash said the bison sometimes move as early as December, but more often the animals move from February to April.

Regardless, Yellowstone wildlife managers and officials with the Montana Department of Livestock are preparing for a busy winter, according to Nash. “All the agencies realize that the potential exists this year for bison movement in some significant numbers and severe weather, if it were to occur — that certainly has the potential to increase the animals that may leave the boundaries,” he said. “[But] they are wild animals; they are unpredictable.”   

The Montana Department of Livestock is the lead agency for hazing operations, and typically handles bison that have left the west entrance of the park into West Yellowtone. Yellowstone wildlife managers often haze bison that leave the north entrance into Gardiner.

If hazing doesn’t work, the Interagency Bison Management Plan, adopted in 2000, allows the agencies to capture bison and ship them to slaughter. The State of Montana also started a bison hunt in 2005. Hunters have killed 44 bison in the hunt so far this winter.

During the 2005-06 winter, hunters and wildlife managers killed 1,016 bison in both the hunt and the slaughter combined.

Stephany Seay, media coordinator for the Buffalo Field Campaign, called the hunt and the slaughter a “sorry approach to wildlife management.”

“They are already telling us explicitly that they’re going to be really aggressive on the buffalo once the hunt is over,” she said. “It sounds like they’re intending to slaughter quite a large number [of bison]. We’re certainly not pleased.”

Seay said that conservation efforts that set aside land outside the park for bison are a better option. For instance, she said owners of the former Munn Ranch near West Yellowstone have agreed to allow bison to roam unmolested on their roughly 800-acre property.

Tim Stevens, Yellowstone program manager for the National Parks Conservation Association, agreed with Seay that management of the Yellowstone bison herd is “heavy-handed.”

Wildlife managers should, instead, make sure the bison have access the habitat that they need, he said.