Siberian fur trade to overhunting. Instead of one sable pelt, the following was accepted as its equivalent: one fox, glutton (relative of the marten), or otter pelt; two blue-fox pelts; sixteen polar-fox pelts; or one hundred squirrel pelts. The Russian government decided the amount of other pelts that were equivalent to the sable pelt. Within forty years, almost all Siberian natives were forced into paying fur tribute to the Russians. Russian traders, hunters, and explorers reached the Pacific coastline by 1650 and were collecting fur tribute from most natives along the coast. Beyond the yasuk, the Russians had two principal ways of obtaining
American marten martes"). Specific predators vary by geographic region. In Newfoundland, red foxes ("Vulpes vulpes") were the most frequent predator, though coyote ("Canis latrans") and other American marten were also responsible for some deaths. In deciduous forests in northeastern British Columbia, most predation was attributed to raptors. Of 18 American marten killed by predators in northeastern Oregon, 8 were killed by bobcats ("Lynx rufus"), 4 by raptors, 4 by other American marten, and 2 by coyotes. Throughout the distribution of American marten, other predators include the great horned owl ("Bubo virginianus"), bald eagle ("Haliaeetus leucocephalus"), golden eagle ("Aquila chrysaetos"), Canada lynx ("L.