ursus

Ursus is a genus in the bear family, Ursidae. It comprises the four extant species commonly recognized as bears: brown bear (Ursus arctos), polar bear (Ursus maritimus), American black bear (Ursus americanus), and Asian black bear (Ursus thibetanus). The name ursus comes from Latin for bear. The genus also includes several extinct species, such as the cave bear (Ursus spelaeus) and Ursus etruscus, known from Pliocene and Pleistocene deposits.

Members of Ursus occur across North America, Europe, and much of northern Asia, occupying forests, mountains, tundra, and, for the polar bear, Arctic sea ice. They are generally solitary, with females caring for cubs for two to three years. Diets are opportunistic and vary by species and season, ranging from berries, roots, and fish to ungulates and carrion. They are strong swimmers and can cover large distances.

The genus arose in the Miocene to Pliocene and diversified during the Pleistocene. Within conservation, statuses vary: polar bear and some populations of Asiatic black bear are listed as Vulnerable; American black bear and brown bear populations are generally listed as Least Concern, though regional declines occur. Taxonomy within Ursus has been subject to revision with molecular data; some authorities question whether the brown and polar bears should be placed in a separate genus or retain Ursus, and some black bears have been treated as separate genera in the past. Overall, Ursus represents the most widely distributed bears, but local populations face threats from habitat loss, climate change, and human-wildlife conflict.