Three airplane surveys were conducted with a high count of the population at 4,230 bison. There are approximately 2,600 bison in the Northern herd and 1,600 in the Central herd this summer. There were about 600 calves-of-the-year observed in a June aerial survey.
This year’s observations represent an increase of nearly 14% over last year’s count. The peak population estimate of 5,000 bison was recorded in the summer 2005.
The observed rate of population change this past year is within the natural range of expectation for wild bison.
This population estimate is used to inform adaptive management strategies under the Interagency Bison Management Plan (IBMP). The IBMP is a cooperative plan designed to conserve a viable, wild bison population while minimizing the risk of brucellosis transmission between bison and cattle.