Wolves, bears, and cougars are the three main predators that actively hunt moose. Each targets different age groups and uses different strategies, and a healthy adult moose is one of the most dangerous prey animals in North America. Understanding which predators take moose, and how, reveals a lot about why moose populations rise and fall across the continent.
Wolves: The Primary Moose Predator
Gray wolves are the most significant predator of moose across most of their shared range. They hunt in packs and are one of the few predators capable of regularly killing full-grown adults, though success is far from guaranteed. Studies using snow tracking in Scandinavia estimated wolf hunting success on moose at roughly 27% to 64%, depending on how success was measured. The wide range reflects how difficult moose are to bring down. Many hunts end with the wolves giving up after a brief chase.
The age and experience of wolves matters more than pack size. Research found that the age of the breeding male was the strongest predictor of whether a hunt succeeded, with peak effectiveness around 4.5 to 5.5 years old. Younger or older wolves led less successful hunts regardless of how many packmates joined in.
The relationship between wolves and moose is one of the best-studied predator-prey dynamics in ecology. Isle Royale National Park in Lake Superior has been a natural laboratory for decades. As of 2024, the island held an estimated 30 wolves and 840 moose. That moose population has declined nearly 60% since peaking at just over 2,000 in 2019, driven partly by wolf predation after new wolves were introduced to the island. The ratio shifts constantly: when moose are abundant, wolves thrive and reproduce; as moose decline, wolf numbers eventually follow.
Bears Target Calves in Spring
Both grizzly bears and black bears are major moose predators, but they operate very differently from wolves. Bears focus heavily on newborn calves during the spring calving season, when young moose are small, slow, and vulnerable. A grizzly or black bear patrolling calving areas in May and June can kill multiple calves in a short period. Adult moose are far riskier targets, and bears generally avoid healthy adults unless the animal is already weakened by injury, deep snow, or starvation.
Grizzlies are more effective moose predators than black bears simply because of their size and aggression, but black bears kill a surprising number of calves in regions where they overlap with moose. In parts of Alaska and northern Canada, bear predation on calves can be a major factor limiting moose population growth, sometimes rivaling wolves in total impact during calving season.
Cougars: A Newer Threat to Moose
Cougars were not historically considered significant moose predators, but research over the past few decades has changed that picture. In southwestern Alberta, a detailed study found that cougars killed moose regularly in winter, but almost exclusively targeted young animals. Of 50 moose killed by cougars in the study, 88% were calves between 7 and 12 months old, and the rest were yearlings under 20 months. No adult moose were confirmed killed by cougars, suggesting that adults are simply too large and dangerous for a solitary cat to tackle.
Male cougars were far more likely to hunt moose than females. Males killed moose at a rate of about 4.4 per 100 winter days, and moose made up an estimated 92% of the biomass they consumed in winter. Female cougars killed moose at roughly one-tenth that rate, with moose comprising only about 12% of their winter diet. The size difference between male and female cougars likely explains the gap: taking down even a young moose requires considerable strength.
As cougar populations expand northward into moose habitat in parts of western Canada and the northern U.S., their role as moose predators is expected to grow.
How Moose Defend Themselves
Moose are not passive prey. An adult moose stands six to seven feet tall at the shoulder, weighs around 1,000 pounds, and can kick in virtually any direction with lethal force. Unlike bears, moose don’t bite. They kick, stomp, and charge.
Their hind legs deliver fast, powerful strikes. Alaska Department of Fish and Game biologists have described hearing tendons and ligaments snap from the sheer force of a moose’s hind kick at full extension. They can also rear up on their hind legs and stomp downward, or box with their front hooves. When standing on hind legs, a moose reaches nine feet tall, placing its hooves above a person’s head. One biologist examined a dead wolf in Denali National Park that had its ribs smashed inward, almost certainly from a moose kick.
Even grizzly bears aren’t safe. In one documented encounter, a cow moose defending her calf sent a 300-plus-pound grizzly tumbling backward with a single strike from her front hooves. The force and balance required for a 1,000-pound animal to flip a running bear is remarkable. In another observation, a cow moose fended off wolves by charging and kicking with both front and back legs, stomping ferociously enough that a single connected blow would have been fatal.
This defensive ability is exactly why predators overwhelmingly target calves and weakened adults. A healthy adult moose that stands its ground is one of the most dangerous animals a wolf pack or bear can confront.
Winter Ticks: A Hidden Killer
Not all moose mortality comes from teeth and claws. Winter ticks have become the leading cause of death for moose under one year old in parts of their eastern range. In sections of Maine’s core moose habitat, calf mortality from winter ticks has exceeded 50%. A single moose can carry tens of thousands of ticks, which feed on blood throughout the winter and early spring. Heavily infested moose rub off large patches of their insulating fur trying to rid themselves of ticks, earning them the name “ghost moose” for their pale, hairless appearance. The combination of blood loss and exposure during cold months is often fatal, especially for young animals that lack the body reserves to survive both parasites and winter.
In the northeastern United States and eastern Canada, where wolf and grizzly populations are absent or very low, winter ticks have effectively filled the role of top predator in regulating moose numbers. Shorter winters driven by climate change allow more ticks to survive into spring, worsening the problem.
Orcas: Extremely Rare but Documented
Moose occasionally swim between islands and across coastal waterways, which puts them in contact with a predator no one would expect. In June 1992 near Pleasant Island, Alaska, killer whales seized, killed, and consumed a moose that was swimming between land masses. This remains the only well-documented case. A global review of killer whale prey noted that the interaction has never been reported again, even with the rise of social media and citizen science, making it an ecological curiosity rather than a meaningful source of moose mortality.