American marten canadensis"), mountain lion ("Puma concolor"), fisher ("M. pennanti"), wolverine ("Gulo gulo"), grizzly bear ("Ursus arctos horribilis"), American black bear ("U. americanus"), and grey wolf ("C. lupus"). In northeastern Oregon, most predation (67%) occurred between May and August, and no predation occurred between December and February. The fur of the American marten is shiny and luxuriant, resembling that of the closely related sable. At the turn of the twentieth century, the American marten population was depleted due to the fur trade. The Hudson's Bay Company traded in pelts from this species among others. Numerous protection measures and reintroduction efforts have allowed
American marten the larger fisher. The Newfoundland subspecies of this animal ("Martes americana atrata") is considered to be threatened. The Pacific Northwest subspecies, the Humboldt marten, is even more so, with only a few hundred individuals remaining. Compared to other carnivores, American marten population density is low for their body size. One review reports population densities ranging from 0.4 to 2.5 individuals/km. Population density may vary annually or seasonally. Low population densities have been associated with low abundance of prey species. Home range size of the American marten is extremely variable, with differences attributable to sex, year, geographic area, prey availability, cover