American bison. Native to the grasslands of North America, it is now found in native populations in the United States and Canada. Large males can reach about 900 kg and females about 400 kg; both sexes develop horns. It is a primarily grass-eating ruminant that spends much of the day feeding. Herds live in female-led and male-led groups, and fierce fights between males occur during the breeding season. The species was drastically reduced in the early 20th century; many individuals are now under management, and its conservation status is Near Threatened.