page_title: Northern Rocky Mountain wolf
section_title: Dietary habits
hierarchical_section_title: Northern Rocky Mountain wolf / Physiology / Dietary habits
caption_attribution_description: Comparison between skulls of Canis lupus irremotus and Canis lupus occidentalis.
context_page_description: The northern Rocky Mountain wolf is a subspecies of gray wolf native to the northern Rocky Mountains. It is a light-colored, medium to large-sized subspecies with a narrow, flattened frontal bone. The subspecies was initially listed as Endangered on March 9, 1978, but had the classification removed in the year 2000 due to the effects of the Northern Rocky Mountain Wolf Recovery Plan. On August 6, 2010, the northern Rocky Mountain wolf was ordered to be returned under Endangered Species Act protections by U.S. District Judge Donald Molloy in a decision overturning a previous ruling by the U.S. Fish and Wildlife Service. They were later removed on August 31, 2012 from the list because of Idaho, Montana, and Wyoming meeting the population quotas for the species to be considered stable. This wolf is recognized as a subspecies of Canis lupus in the taxonomic authority Mammal Species of the World.
context_section_description: The northern Rocky Mountain wolf preys primarily on the bison, elk, the Rocky Mountain mule deer, and the beaver, though it is an opportunistic animal and will prey upon other species if the chance arises. But, for the most part, small prey animals do not make up a large part of its diet.
  When an individual or a pack is able to take down numerous prey, the amount a northern Rocky Mountain wolf eats daily will generally make up about 10–21% of its body mass, though there have been recorded instances of an individual eating up to 37% of its body mass. However, when prey is not as plentiful, northern Rocky Mountain wolves are able to survive for considerably long periods of time while eating only small amounts. Cannibalism, in times of severe food shortage, occurs, as a pack will  kill and eat an injured or weak member of the group.
caption: Two wolf subspecies that live in the northern Rocky Mountains: Canis lupus irremotus (left) and Canis lupus occidentalis (right)
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