Fur trade marten furs could generate in international markets spurred a "fur fever" in which many Russians moved to Siberia as independent trappers. From 1585 to 1680, tens of thousands of sable and other valuable pelts were obtained in Siberia each year. The primary way for the Muscovite state to obtain furs was by exacting a fur tribute from the Siberian natives, called a "yasak". "Yasak" was usually a fixed number of sable pelts which every male tribe member who was at least fifteen years old had to supply to Russian officials. Officials enforced "yasak" through coercion and by taking hostages, usually
American marten more vulnerable than females. American marten are particularly vulnerable to trapping mortality in industrial forests. Other sources of mortality include drowning, starvation, exposure, choking, and infections associated with injury. During live trapping, high mortality may occur if individuals become wet in cold weather. American marten host several internal and external parasites, including helminths, fleas (Siphonaptera), and ticks (Ixodida). American marten in central Ontario carried both toxoplasmosis and Aleutian disease, but neither affliction was suspected to cause significant mortality. High American marten mortality in Newfoundland was caused by encephalitis. American marten The American marten or American pine marten ("Martes americana") is