Bison Ecology & Management education module - Page 7

Next page or back to Table of Contents

Project Activity. Part 1: Bison Population Counts & Management Policies
Bison leaving Yellowstone National Park in certain winters & the related multi-agency Culling Policy.
•How has bison population size changed over the past century?
•What factors have influenced changes in population size over the past century? (natural & human)
Part A. The Yellowstone National Park Bison Population from 1900-2000 (80 pts)
  • Use the “Bison Counts” excel file (on Blackboard) to graph the following:
    • Northern Herd Bison Count from 1900 – 2000
    • Central Herd Bison Count from 1900 – 2000
    • Total Park Bison Count from 1900 – 2000
  • Use the “Bison Removal” excel file to graph the following:
    • Northern Herd Bison Removals from 1900 – 2000
    • Central Herd Bison Removals from 1900 – 2000
    • Total Park Bison Count Removals from 1900 – 2000
  • When were the periods of culling for the Northern Herd? For the Central Herd? (Can indicate by “no culling”, “low culling”, “high culling”).
  • Research the Yellowstone National Park culling policy during this 100 year time period for both the Northern Herd and the Central Herd. What policies were in effect for each herd during what years in the past century? Check documents on the NPS website under “bison” for details:
  • Combine this information with population count information to indicate periods of “No Culling”, “Low Culling”, or “High Culling” on each of your graphs in #1
  • Describe, in ecological terms, the population growth pattern of each herd over the past century with respect to Park culling policies.
Part B: Background Info on Forest and Rangeland Management policies (20 pts)

Public land in the GYE is managed by the National Park Service, the USDA Forest Service, the US Fish and Wildlife Service (National Wildlife Refuges) and the Bureau of Land Management. The remaining land in the GYE is privately owned.

Browse the United States Forest Service (, Bureau of Land Management (, and National Park Service ( websites and answer the questions below.

  • Using the websites listed above, find the mission statement of each government agency. Be sure to read the entire mission statement carefully. How do they differ? How might any differences affect how public lands are managed?
  • What are the rules for livestock production and grazing under these different land management organizations?
  • The U.S. government has kept timber sale prices and grazing leases low to maintain low prices of lumber and meat for consumers and to help support rural communities and traditional ways of life. How would you weigh those human interests against the ecological values of forests and rangelands?

Data Files (#1 and #2)










29 Nov 2006 Webmaster