BOZEMAN (AP) – Wildlife managers are considering changes to the hunting and slaughter of bison that leave Yellowstone National Park after past efforts failed to achieve population reduction goals set by a 2000 agreement.

Roughly 600 bison were killed during the past winter, including through shipments of the animals to slaughter and hunting by American Indians and state-licensed hunters.

Despite the hundreds of animals killed, officials told the Bozeman Daily Chronicle that the park’s bison population saw no significant decrease.

Montana officials and many ranchers have pushed to curb the park’s bison population, which migrate by the thousands into the state when Yellowstone has severe winters. They can compete with livestock for grazing space and many bison carry brucellosis, a disease that can cause cattle to abort.

A 2000 agreement between Montana and federal agencies requires bison kept out of areas with cattle, resulting in thousands of bison captured and slaughtered and drawing condemnation from wildlife advocates.

Last year, officials held off from capturing bison until Feb. 15 to let hunting play a more significant role in reducing the population. But the move made it tougher to capture bison, resulting in fewer sent to slaughter.

John Harrison, a staff attorney for the Confederated Salish and Kootenai Tribes, said the delayed capture date “created a little more of an urgency” as hunters tried to take all the bison they could before trapping began.

People who live close to where hunting is concentrated, near Gardiner, have raised concerns over gunfire and gut piles left behind after the hunters are done that can attract scavenging bears.

The problem got worse last winter, after tribal governments and the state agreed to suspend hunting every other week to reduce pressure.

Instead the move concentrated the hunting pressure and led to congestion and more safety problems, officials said.

There have been no recorded transmissions of brucellosis from bison to cattle. There have been numerous brucellosis transmissions to cattle from elk.

Tens of thousands of elk roam the Yellowstone area and unlike bison there are no restrictions on where they can roam. Elk are widely hunted but not captured for slaughter.

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