Re: Yellowstone Releases Summer 2013 Bison Population Estimate

Yellowstone National Park has completed its annual summer bison population abundance monitoring. The population is estimated to be 4,600 bison. The estimate is based on a series of aerial surveys. There are approximately 3,200 bison in the Northern herd and 1,400 in the Central herd this summer. There were about 700 calves-of-the-year observed in a June aerial survey.

This year’s observations represent an increase of 8.75% 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. The cooperating agencies operating under the IBMP are the National Park Service, the U.S. Forest Service, the Animal and Plant Health Inspection Service, the Montana Department of Livestock, the Montana Department of Fish, Wildlife and Parks, the InterTribal Buffalo Council, the Confederated Salish Kootenai Tribes, and the Nez Perce Tribe. More information on the IBMP can be found at http://ibmp.info.

When I accepted employment in Yellowstone in 1974, I read a 1972 game survey that reported 750 bison in Yellowstone. In recent years, I have grown a bit skeptical of game surveys.

Interesting to note: The first case of brucellosis in Yellowstone bison was in 1917. Interesting enough the bison caught the brucellosis from cattle that were grazed in the park and held in confinement with the bison. There has never been a documented case of transmission of brucellosis from bison to cattle under normal circumstances.

Yer talkin like one o' them sheep farmers.

---

Old Dude