Why do we see more black bears in the Fall?
American black bear
American black bears are one of three species of bears found in North America. The largest is the polar bear, followed by the brown bear, and finally the black bear. The name black bear is a bit of a misnomer since the species can be found in several different colorations. While black is most common, they also occur in cinnamon, brown, blue/gray, blonde, and occasionally even white.
The black bear is the most abundant and widely distributed of the bear species in North America, occurring throughout most of the United States, Canada, and in the northern half of Mexico. As such, people interact with this species most often. Black bears are opportunistic feeders, and their diets consist of leaves, grasses, crops, roots, fruits, insects, and fish. Being opportunistic, though, they will feed on carrion and other food sources, and occasionally kill other animals for food. This opportunistic behavior can result in bears becoming conditioned to readily available human food sources such as trash and food around campgrounds and houses, resulting in frequent visitation of bears to these areas. When bears become conditioned to a readily available human food source, there is a greater opportunity for negative interactions with people.
Black bear approaches screen door of house adjacent to woodland. Photo Credit: Alyssa DeLiberto
Most human-black bear interactions occur in spring through fall. Encounters can happen in winter if bears are disturbed in their dens in the North and in the southern United States and Mexico where long periods of hibernation are less frequent. In late summer and fall, prior to hibernation, bears enter a physiologic state called hyperphagia characterized by a dramatic increase in the search for and consumption of food. During this time, bears can eat 15,000-20,000 calories per day. This high caloric need can result in increased visitation to readily available, high energy, food sources such as fruit trees, berry bushes, bird food, beehives, pet food, and trash commonly found around houses. Eliminating such food sources will decrease the attractiveness of a property to bears.
Black Bears eating food scraps.
After hyperphagia and prior to hibernation, bears enter a transition period when they become increasingly lethargic, sleeping up to 22 hours per day, and their metabolism gradually slows in preparation for hibernation. In more northern regions, bears generally enter the den upon arrival of the first snow and when the temperature reaches 32°F. However, in western arid areas, where food resources are traditionally scarce in the fall, bears may enter hibernation early in the season regardless of food supply. Alternatively, in eastern North America where food resources such as acorns and nuts can remain throughout the winter, bears begin hibernation in late November or December. The first group of bears to start hibernating are pregnant females, followed by females with older dependent offspring and subadult bears. Adult males enter dens and start hibernating the latest.
Although aggressive behavior to humans by black bears is not common, habituation to food sources around human dwellings increases the likelihood of defensive or offensive aggressive behavior towards people. Most encounters with bears near houses result in an animal fleeing or climbing a tree for safety. In the latter instance, simply bringing family members and pets indoors and allowing the bear time to safely leave the tree and property, resolves the conflict.
Many of us are empathetic to wildlife and want to help them, often by providing food. Unfortunately, doing so acclimates them to our presence and encourages unsafe interactions. The best way to help bears and other wildlife is to keep them wild. When bears do come into towns and onto our properties, remove bird feeders, secure trash, and do not provide them with other food sources. Respect them by giving them space, and not approaching them.
