BILLINGS, Mont. — Roughly 500 to 600 bison that migrated out of Yellowstone National Park last winter are back on their summer feeding grounds, after being hazed into the park by state and federal personnel.
Only one migrating bison was killed this winter, by a Montana hunter. The prior winter 1,601 bison were killed, most of them captured and slaughtered to prevent the spread of the disease brucellosis to cattle.
The disease causes pregnant cattle, elk and bison to miscarry.
About half of Yellowstone bison carry the disease, but there have been no known bison-to-cattle transmissions in the wild.
With Yellowstone’s bison population down sharply — about 3,000 from 4,700 two years ago — this winter’s migration in search of food at lower elevations was smaller than in recent years.
Christian Mackay, the head of the Montana Department of Livestock, said the hazing program lasted about 10 days and pushed the bison into an area about 15 miles inside the park in northwestern Wyoming.
“In a very staged manner, we moved a total of probably between 500 and 600 animals,” he said. “At any given time, we were moving 50 to 100 to 250” bison.
Conservation and bison advocacy groups wanted the animals left outside the park, where some private landowners have welcomed the animals on their property.
But the Montana Stockgrowers Association and Yellowstone-area ranch owners have held officials to a policy of returning bison to the park before cattle are shipped into the area for summer feeding.
This year, most bison were back in the park by the stockgrower group’s preferred date of May 15.
