A buffalo has a shaggy, long, dark-brown winter coat, and a lighter-weight, lighter-brown summer coat. The male bison is slightly larger than the female and, in some cases, can be considerably heavier. Bison areĀ herbivores, grazing on the grasses andĀ sedges. Their daily schedule involves two-hour periods of grazing, resting, and cud chewing, then moving to a new location to graze again.