Britannica
Sources used in this answer
Why did American bison migrate across the Great Plains?
Created from Britannica articles
using AI.
AI can make mistakes, so verify using Britannica articles.
Migration
A herd of common wildebeest (Connochaetes taurinus) migrating across a dusty savanna in Africa. The animal is a keystone species (i.e., a species with a disproportionately large effect on its biological community) in plains and acacia savanna ecosystems from southeastern Africa to central Kenya.
American bison migrated across the Great Plains primarily in response to seasonal changes in climate and the availability of food. These herds undertook regular, circular migrations, moving southward in the fall to spend the winter in areas 320 to 640 kilometers (200 to 400 miles) away from their summer range.1
When warmer weather returned in the spring, the bison moved back north, following the growth of fresh grass triggered by spring rains. These seasonal movements allowed the animals to access optimal grazing conditions throughout the year, as they relied on grass and herbs as their primary food sources.21