What Do Black Bears Eat in the Wild?

American black bears (Ursus americanus) are highly adaptable mammals found across North America. Their diet, which consists of both plant and animal matter, varies significantly with season and geographic location, reflecting their flexible eating habits.

General Dietary Habits

Black bears are opportunistic foragers, readily consuming a wide variety of food sources. Plant matter forms the largest part of their diet, often comprising 80% to 90% of what they eat. This includes grasses, roots, berries, nuts, and other vegetation. Their digestive systems are well-suited to process substantial amounts of plant material, even though they lack a cecum, common in herbivores for breaking down fibrous plant structures.

Beyond plants, black bears supplement their diet with animal proteins when available. Insects like ants, beetles, wasps, and their larvae are a common protein source, often found by tearing into logs or turning over rocks. Less frequently, they may also consume small mammals, fish, or carrion. Their powerful sense of smell, which can detect food sources from over two miles away, aids them in finding these diverse food items.

Seasonal Shifts in Food Sources

A black bear’s diet changes significantly throughout the year, primarily driven by food availability.

After emerging from winter dormancy, bears seek out emerging vegetation in spring. Tender shoots, young leaves, and early plants like clovers, dandelions, and skunk cabbage provide nutrients. They may also scavenge on carrion, and insects like ants and beetles begin to emerge, offering protein.

In summer, the diet shifts to incorporate many soft fruits and berries. Blueberries, raspberries, blackberries, and serviceberries become staple foods, providing sugars for energy. Insects continue to be a part of their diet, with bears actively foraging for grubs and larvae under rocks and logs. In some regions, if accessible, fish can also become a protein source.

Fall is an important period for black bears as they prepare for hibernation, entering a phase of increased eating known as hyperphagia. During these months, they consume high-calorie foods to build fat reserves. Acorns, hickory nuts, and beechnuts are important hard mast foods, along with late-season fruits. Bears can consume up to 20,000 calories a day, often doubling their weight in preparation for winter months, relying on stored fat.

Beyond Natural Foraging: Human Influences on Diet

Human activities can alter the natural foraging patterns and diet of black bears. Bears living near human developments often encounter easily accessible human-provided food sources. These include garbage, bird feeder contents, pet food left outdoors, and barbecue scraps. Agricultural crops such as corn, oats, and fruit from orchards can also attract bears, leading to conflicts with farmers.

Relying on human-provided food can have several negative consequences. It can lead to habituation, where bears lose their natural fear of humans and associate people with food. This increased proximity often results in more human-bear conflicts, including property damage or encounters that may lead to bear removal or lethal management. Furthermore, diets heavily reliant on human foods can lead to nutritional deficiencies and health problems, as these foods often lack balanced nutrients.