occurs (regularly, as a native taxon) in multiple nations
Regularity: Regularly occurring
Type of Residency: Year-round
National NatureServe Conservation Status
Rounded National Status Rank: N4 - Apparently Secure
Mackenzie Valley wolf
The northwestern wolf (Canis lupus occidentalis), also known as the Mackenzie Valley wolf, British Columbia wolf or northern timber wolf is a subspecies of gray wolf which ranges from the upper Mackenzie River Valley, southward into central Alberta. It is one of the largest wolves in North America, and varies greatly in color from black to pure white.
The American Wolf of the northern districts is covered with long and comparatively fine fur, mixed with a large quantity of shorter woolly hair, and it has a more robust form than the European Wolf. Its muzzle is thicker and more obtuse, its head larger and rounder, and there is a sensible depression at the union of the nose and forehead. Its more arched forehead is comparatively broad, the space between the ears being greater than their height. The ears are shorter, wider at the base, and more acute, and have, consequently, a more conical form, whilst the greater length of the hair on the side of the neck of this Wolf makes them appear even shorter than they are. Its neck, covered with a bushy fur, appears short and thick. Its legs are rather short, its feet broad, with thick toes, and its tail is bushy, like the brush of a fox.
He chose to give it the name occidentalis in reference to its geographic location rather than label it by its color, as it was too variable to warrant such.
Phylogenetic analyses of North American gray wolves show that there are three clades corresponding to C. l. occidentalis, C. l. nubilus and C. l. baileyi, each one representing a separate invasion into North America from distinct Eurasian ancestors. C. l. occidentalis, the most northwestern subspecies, is descended from the last gray wolves to colonize North America. It likely crossed into North America through the Bering land bridge after the last ice age, displacing C. l. nubilus populations as it advanced, a process which has continued till present times.
The northwestern wolf is one of the largest gray wolves in North America. The average weight of 147 wolves captured in Denali National park between 1986 and 1994 was 40 kilograms (88 lb) for females and 47 kilograms (104 lb) for males. The heaviest recorded specimen was killed on 70 Mile River in east-central Alaska on July 12, 1939 and weighed 79.4 kilograms (175 lb).
Current status and history
The northwestern wolf was the subspecies used in the Yellowstone introduction effort, where it has become a successful apex predator much as it is in its vast northern range. In Yellowstone, it has been crucial in restoring environmental balance in that it has clamped down on the less fit members of the herds on which it feeds, thereby keeping large ungulate numbers in check and allowing certain floral and faunal species to recover, promoting biodiversity. Wolves were also introduced in central Idaho and entered northwest Montana from Canada. The wolf population in the Northern Rockies has since grown to an estimated 1,300 animals. The wolf population in Alaska is estimated at 7,500–11,000.
The protection given to the northwestern wolf has allowed its population to rise dramatically, causing several young animals to leave the boundraries of Yellowstone and establish territories in areas where they may enter conflict with humans. In Wyoming and Idaho, 90 wolves have been killed to date because of livestock run-ins. In Montana, 32 wolves were killed in 2007 by federal agents. The Montana figure does not include an unknown number of wolves killed by ranchers defending their livestock. The death toll hit a record figure of 142 wolves in 2006. Federal officials plan to remove gray wolves in the Northern Rocky Mountains from the endangered species list in February 2008, although court challenges are considered inevitable and could delay a final delisting. In the Rocky mountains, non-lethal responses to livestock kills, such as hazing wolves away from a ranch, are used when they can be pushed into an area without livestock.
Since its reintroduction to Yellowstone, the northwestern wolf's possible involvement in the decline of elk populations has been a subject of controversy. On one hand, Yellowstone officials have stated that computer analysis indicates that there is greater justification for believing that the human hunting rate and severe climate account for the majority of the decline, with wolf predation amounting to very little. Others state that the decline is an inevitable result of an exploded wolf population.
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