Members of the "Ursus arctos" (brown bear) species can reach masses of . The Mexican grizzly bear ("Ursus arctos nelsoni") is extinct. Brown bears ("Ursus arctos") have been found to feed on ants. The grizzly bear ("Ursus arctos horribilis") is a North American subspecies. Subsequent taxonomic work merged all North American brown bears into a single species ("Ursus arctos"). The grizzly bear ("Ursus arctos" ssp.) is the great brown bear of North America. The closest surviving brown bear is Ursus arctos middendorffi in Alaska. Martes martes, Lynx lynx, Felis sylvestris, Ursus arctos, Meles meles, Lepus, Erinaceus europaeus and Sciurus. The brown bear ("Ursus arctos") is a bear species found across Eurasia and North America. There are three populations of the Hokkaido brown bear subspecies ("Ursus arctos yesoensis"). The Atlas bear "(Ursus arctos crowtheri)" and Barbary lion "(Panthera leo leo)" are extinct. In 1963 Rausch reduced the number of North American subspecies to one, "Ursus arctos middendorffi".