Black bears are highly adaptable omnivores, meaning their diet includes both plant and animal matter. Their food choices are heavily influenced by what is available in their environment, changing throughout the year. This adaptability allows them to thrive in diverse North American habitats.
Primary Food Sources
The bulk of a black bear’s diet primarily consists of plant-based foods, often making up 80% to 90% of their intake. They consume a wide variety of vegetation, including berries like blueberries, raspberries, and blackberries, along with nuts such as acorns, hickory nuts, and beechnuts. Black bears also forage for roots, tubers, grasses, leaves, and buds, adapting their consumption to the specific plant life in their region.
Insects are another important food source for black bears, providing essential protein and fats. They commonly eat ants, bees, wasps, grubs, and larvae, often found by tearing apart rotting logs or digging into the ground. Bears may also seek out honey from beehives. While capable of hunting, animal matter typically forms a smaller portion of their overall diet.
Meat consumption is less frequent for black bears compared to plants and insects. They may prey on small mammals like rodents or fawns, and occasionally consume fish, birds, or eggs. Black bears also scavenge on carrion. This preference for calorie-dense plant foods is evident during periods of hyperphagia.
Seasonal Dietary Shifts
A black bear’s diet undergoes significant changes throughout the year, driven by seasonal food availability. In spring, as bears emerge from hibernation, their diet shifts to new growth such as grasses, forbs, and emerging insects. They also scavenge on carrion, providing a protein boost. This helps them regain strength after months of dormancy.
During summer, the diet transitions to an abundance of ripe fruits and berries. Black bears consume large quantities of these sugary foods, along with an increased intake of insects. This period allows them to build energy reserves.
Fall is a period known as hyperphagia, where black bears consume vast amounts of food to build fat reserves for winter hibernation. Their focus shifts to high-calorie foods like nuts and late-season berries, which are rich in fats and carbohydrates. During this time, a bear can consume over 20,000 calories per day and may gain 20% to 30% or more of their body weight. This intense foraging is important for their survival through winter.
Opportunistic Foraging
Black bears are highly opportunistic foragers, exploiting readily available food sources, especially when natural foods are scarce. They seek out human-associated foods, which are often calorie-dense and easily accessible. Common examples include garbage, birdseed, pet food left outdoors, and compost piles. Agricultural crops, such as cornfields and fruit orchards, also become attractive food sources.
This foraging behavior is not necessarily a preference for human food over natural sources, but a result of their acute sense of smell, which can detect food from over two miles away. Bears are driven to consume as many calories as possible, particularly during hyperphagia. Securing attractants, such as properly storing garbage and pet food, is important to prevent bears from becoming reliant on human-provided food and to minimize potential human-bear conflicts.