Yellowstone's Summer 2009 Bison Population Estimate Released
Contact: Al Nash, 307-344-2015
National Park Service
Yellowstone National Park
Yellowstone National Park has completed a bison population abundance estimate.
The population is estimated to be 3,300 bison. The estimate is based on a series of aerial surveys conducted in June and July.
The population now includes 2,800 adult and yearling bison, and 500 calves of the year. The population is about equally distributed between the Central Interior and Northern Range herds.
The population was estimated at 3,000 bison last summer; and at 2,900 adult and yearling bison in late winter. The peak population estimate of 4,900 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. The rate at which wildlife populations increase in abundance is a reflection of the combined effects of reproduction and mortality, and is heavily influenced by age structure of the population, and habitat conditions encountered over the course of time.
The five 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, and the Montana Department of Fish, Wildlife and Parks.
- www.nps.gov/yell -
Did You Know?
The 1988 fires affected 793,880 acres or 36 percent of the park. Five fires burned into the park that year from adjacent public lands. The largest, the North Fork Fire, started from a discarded cigarette. It burned more than 410,000 acres.