Hart reviews and maps travelers' observations of bison during journeys across the U.S. and Canadian Great Plains in the 1700's to 1870's to examine whether bison "flash grazed", that is, grazed heavily for a short time, moved on, and did not return for months or even years. For example, Lewis and Clark observed bison near their camp at the Great Falls of the Missouri on 19 of 29 days, and traveler Charles Goodnight observed a herd in a dry year in the Texas Panhandle remain in place until thousands died of starvation, despite the availability of forage in an area 30 miles away. Further, herd numbers in the range of 10,000 head or more suggest little opportunity for movement to long-rested range, and travelers often noted severe range condition along major Great Plains rivers. Hart notes that while bison moved, it does not appear they "migrated". Often bison were found continuously in the same location for weeks or months. At other times they were absent, and neither presence nor absence followed predictable patterns. Thus, the hypothesis that migration of free-ranging wild bison was common is not supported by the recorded observations. Nor is the other hypothesis, that bison "flash grazed", supported by the observations available. Although a herd may have moved on after a few days of grazing, densities of bison appeared to be so great that another herd probably moved in a few days or weeks later and regrazed the area, provided there was anything left to eat.
Citations and enhanced abstracts for journals articles and documents focused on rangeland ecology and management. RSIS is a collaboration between Montana State University, University of Idaho, and University of Wyoming.