Why Were There So Many Bison?

When you research the topic of North American bison (buffalo), you usually come across estimates of continent-wide herds totaling between 30-60 million animals. Those numbers are pretty much ''guestimates'' based on anecdotal observations of chroniclers in the 19th century, including Lewis and Clark's Corps of Discovery in the early 1800s where Lewis estimated one herd encountered along the upper reaches of the Missouri at 20,000 animals. Similar numbers where estimated in the late 1860s. However by 1890, the total population of?Bison bison?numbered probably less than 500 and the majority of those were on a preserve in Canada. Yellowstone had only about 25 animals in the entire park. The reason for such a dramatic population implosion is most often attributed to commercial hide hunters, each of which might kill as many as 4,000 beast in a season.

Paul S. Martin in his book?Twilight of the Mammoths?argues that the number of bison Lewis and Clark encountered may have been the result of the near extermination of the native tribes of North America due to European diseases that are estimated to have taken as many as 95% of the continent's indigenous population: only one-in-twenty survived the ravages of the European disease invasion over a 400 year period. In effect, the drop in human hunting pressure may have allowed a corresponding population explosion among bison, and likely other game animals.

Martin observes (pg 179), "According to Ernest Thompson Seton, early in the nineteenth century, before market hunting began, North America harbored 60 million bison... [however] Seton's extrapolations appear to be based on the assumption that bison were in decline in the early 1800s. In fact, they were on the rise because Native American populations were declining due to exposure to European diseases."

"Even if [indigenous] depopulation were much less severe...it would have considerably diminished human predation pressure on big game...When reported by Lewis and Clark, three centuries after the crisis of [European] contact, bison where thriving as they had not for thousands of years, if ever."

Reprinted from Camp1872 Xperience "Camp Notes" #53