The nutrient-rich plants help the mothers produce ample amounts of milk for their growing calves. Calves remain under their mother's care for about a year. They must then prepare for the upcoming winter by themselves. Cud is partially digested vegetation, previously swallowed and then regurgitated from the bison's rumen for further processing. A part of the stomach.
Bacteria here break down tough grasses and plants.
While it may look ragged, shedding helps them stay cool. In spring, birds use bison hair to line their nests. Bison roll in dust or mud to stay cool and keep insects away.