FLOURISHING SPECIES

FLOURISHING SPECIES

After the reintroduction of the gray wolf in 1995, researchers noticed drastic changes occurring. Elk, the primary prey of the gray wolf, became less abundant and changed their behavior, freeing riparian zones from constant grazing. The respite allowed willows and aspens to grow, creating habitat for beaver, moose, and scores of other species. In addition to the effects on prey species, the gray wolf’s presence also affected the park’s grizzly bear population. The bears, emerging from hibernation, chose to scavenge off wolf kills to gain needed energy and fatten up after fasting for months. Dozens of other species have been documented scavenging from wolf kills and are now flourishing.

The Yellowstone Park bison herd in Yellowstone National Park is probably the oldest and largest public bison herd in the United States. Yellowstone is known for its geothermal activity and large mammals, especially elk, wolves, American bison, bears, pronghorns, moose and bighorn sheep. The Yellowstone Park bison herd was estimated in 2015 to be 4,900 bison. The bison in the Yellowstone Park bison herd are American bison of the Plains bison subspecies. Yellowstone National Park may be the only location in the United States where free-ranging bison were never extirpated, since they continued to exist in the wild and were not re-introduced, as has been done in most other bison herd areas.