The moose (Alces alces) is the world’s largest extant species in the deer family. This herbivore inhabits the boreal forests of the Northern Hemisphere. Its size, height, length, and weight are results of specialized adaptations to cold environments.
Core Body Dimensions
The scale of an average adult moose is defined by its height, measured to the top of the hump at the shoulder. An adult typically stands between 1.4 and 2.1 meters (4 feet 7 inches to 6 feet 11 inches) at the shoulder, making it the tallest land mammal in North America. This stature helps the moose navigate deep snow and browse on tall shrubs. Body length ranges from 2.4 to 3.1 meters (8 to 10 feet).
Weight is the most variable metric, fluctuating based on season, age, and diet. A mature bull (male) moose generally weighs between 380 and 700 kilograms (838 to 1,543 pounds). The body is supported by long, powerful legs, with the front legs being slightly longer than the rear, aiding movement through dense terrain.
Sexual and Geographic Size Differences
Moose exhibit sexual dimorphism, with bulls (males) being considerably larger and heavier than cows (females). Bulls sometimes outweigh females by more than 40%. Female moose generally weigh between 200 and 490 kilograms (441 to 1,080 pounds). Males continue to grow until about 8 to 10 years of age, while females typically reach their full size around age four.
Size varies dramatically across the species’ vast geographic range, resulting in several recognized subspecies. The largest is the Alaskan or Yukon moose (Alces alces gigas). Bulls of this subspecies commonly stand over 2.1 meters (7 feet) at the shoulder and can weigh up to 820 kilograms (1,808 pounds). In contrast, the Shiras moose, found in the Rocky Mountains, is the smallest North American subspecies.
Antler Size and Structure
The antlers of the bull moose are a key feature, differing from other deer species because they are palmate—broad and flattened like a shovel. Antler size is influenced by the bull’s age, nutrition, and health, with maximum development occurring between five and twelve years of age.
Mature bull antlers can reach a spread of up to 1.8 meters (6 feet) from tip to tip, though confirmed spreads have exceeded 2.1 meters (83 inches). Large pairs average between 20 and 35 kilograms (45 and 75 pounds). These structures are grown and shed annually, developing rapidly in the spring under a layer of vascularized skin called velvet. The growth rate can be up to an inch of bone per day, requiring substantial resources before the autumn mating season.