Moose and caribou are both members of the deer family, but they differ dramatically in size, behavior, habitat, and physical design. A bull moose can weigh over 1,200 pounds, while a bull caribou averages 350 to 400 pounds. That size gap is just the starting point. These two animals occupy different ecological niches, eat different foods, and have evolved strikingly different strategies for surviving northern winters.
Size and Build
Moose are the largest members of the deer family. Adult bulls typically stand about 6 feet tall at the shoulder and weigh between 1,200 and 1,500 pounds, though Alaskan moose can exceed 1,600 pounds. Cows are smaller but still imposing, generally weighing 800 to 1,300 pounds. The moose body plan is built for wading through deep snow and dense brush: long legs, a humped shoulder, and a distinctive drooping snout.
Caribou are considerably leaner and more compact. Bulls average 350 to 400 pounds, and mature cows weigh 175 to 225 pounds. Their build reflects a different survival strategy. Rather than muscling through obstacles, caribou are designed for endurance travel across open tundra and boreal landscapes. They carry less bulk but move with remarkable efficiency over enormous distances.
Antler Differences
Both species grow antlers, but the shape is completely different. Moose antlers grow in a broad, flat “palmate” pattern, forming wide paddle-like plates that can span more than 5 feet across. This shape is unique among deer species and makes moose instantly recognizable.
Caribou antlers are long and branching, sweeping backward and upward with multiple tines. They lack the flat paddle structure of moose antlers. But the most notable difference is who grows them: caribou are the only deer species in which females regularly grow antlers too. Bull caribou shed theirs in late fall or early winter, while cows keep theirs through the winter, likely giving pregnant females an advantage when competing for food at snow craters.
Hooves Built for Different Terrain
Caribou have proportionally larger, more crescent-shaped, and more flexible hooves than moose or any of their other deer relatives. These hooves serve multiple purposes. In winter, they work like shovels, scooping away snow so caribou can reach the lichens buried underneath. On soft snow, their broad surface area acts like a snowshoe, distributing weight to prevent sinking. In summer, the hoof pads get spongier for better traction on wet tundra, and they even function as paddles during river crossings.
Moose hooves are large and pointed, well suited for walking on soft ground in marshes and bogs, but they don’t have the same specialized snow-digging design. Moose rely more on their sheer leg length to navigate deep snow.
What They Eat
The two species have almost entirely different diets, which is a big reason they can share the same landscape without directly competing for food. Moose are browsers. They feed on the leaves, twigs, and bark of deciduous trees and shrubs, especially willows, birch, and aspen. In summer, moose are famous for wading into lakes and rivers to eat aquatic vegetation, submerging their heads to pull up pondweed and water lilies.
Caribou are lichen specialists, particularly in winter. Lichens are slow-growing organisms found on the forest floor and on rocks in mature conifer forests and tundra. Research in northwest Alaska found that lichen abundance was more than three times greater at locations caribou chose to overwinter compared to random spots in the landscape. This reliance on lichens makes caribou vulnerable to wildfires: unburned areas had more than four times the lichen cover of recently burned zones. In summer, caribou shift to grasses, sedges, and the leaves of low shrubs.
Solitary vs. Herd Animals
Moose are solitary by nature. Outside of mating season and the bond between a cow and her calves, you’ll rarely see moose traveling together. They don’t migrate long distances and tend to stay within a relatively small home range, moving between seasonal feeding areas.
Caribou are the opposite. They’re intensely social, forming herds that can exceed 10,000 animals. These massive groups undertake the longest migration of any land mammal, traveling up to 3,000 miles per year between their winter feeding grounds in the boreal forest and summer calving areas on the open tundra. This constant movement allows them to find fresh lichen pastures and escape the worst concentrations of biting insects in summer.
Habitat Preferences
Even where moose and caribou share the same general region, they select very different types of forest. Moose thrive in early successional habitat: young forests regrowing after logging or fire, with abundant deciduous shrubs, fertile soils, and high plant diversity. Large-scale timber harvesting tends to create ideal moose habitat by opening the canopy and encouraging willow and birch growth.
Caribou need the opposite. Woodland caribou depend on late-successional, mature conifer forests with low productivity and thick lichen cover on the ground. Some populations also use muskeg, fens, and bogs in northern Alberta, Saskatchewan, and parts of Quebec. This creates an unfortunate dynamic: forestry practices that benefit moose often destroy caribou habitat. As moose populations expand into logged areas, wolves follow, and those wolves then prey on nearby caribou as well. This cascading effect has contributed to caribou disappearing from much of their southern historical range, including all of Canada’s Maritime Provinces and the New England and Great Lakes states.
How They Handle Predators
Wolves are the primary predator for both species, but moose and caribou defend themselves differently. A full-grown moose can stand its ground. With powerful front hooves capable of killing a wolf and a body mass ten times that of its attacker, a healthy adult moose is a dangerous target. Moose tend to face threats head-on or move into dense cover.
Caribou rely on numbers, distance, and space. Herd living dilutes each individual’s risk, and their migratory lifestyle means they’re often far from established wolf territories. When wolves do pass through caribou range, both caribou and moose adjust their behavior. Research tracking radio-collared animals found that caribou increased their use of lichen-rich conifer stands for nearly 10 days after a wolf passed through, likely because those dense stands offer better concealment. Moose, meanwhile, avoided open conifer stands that wolves favored, instead shifting to denser forest cover.
Naming Confusion Across Continents
The common names for these animals get confusing once you cross the Atlantic. In North America, wild members of the species Rangifer tarandus are called caribou. In Europe and Asia, the same species is called reindeer, whether wild or domesticated. Only in North America does the word “caribou” exist for wild populations.
Moose cause a different naming problem. In North America, “moose” is unambiguous. But in Europe, the same animal is called “elk.” Meanwhile, the animal North Americans call “elk” (the large deer of the Rocky Mountains) is an entirely different species. If someone from Scandinavia mentions seeing an elk, they’re talking about what you’d call a moose. Keeping the scientific names straight helps: moose are Alces, caribou and reindeer are Rangifer, and North American elk are Cervus canadensis.