Fur trade the "yasak" (or iasak) tax on natives and the 10% "Sovereign Tithing Tax" imposed on both the catch and sale of fur pelts. Fur was in great demand in Western Europe, especially sable and marten, since European forest resources had been over-hunted and furs had become extremely scarce. Fur trading allowed Russia to purchase from Europe goods that it lacked, like lead, tin, precious metals, textiles, firearms, and sulphur. Russia also traded furs with Ottoman Turkey and other countries in the Middle East in exchange for silk, textiles, spices, and dried fruit. The high prices that sable, black fox, and
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