Why are female bears protective of their cubs around male bears?

Female bears are highly protective of their cubs in the presence of males because adult male bears are a primary threat to the survival of young bears. While young bears face risks from other carnivores such as wolves or cougars, they are most vulnerable to predation by other bears, particularly adult males.1

Because bears are generally solitary animals that do not form long-term social bonds—with males playing no role in raising their offspring—a female must remain vigilant to ensure the safety of her cubs until they are old enough to fend for themselves.1