Nature Notes: Black Bear
Roused from a deep sleep, I wasn’t sure what woke me, so I lay there listening.
This time it was louder and more insistent. My tentmate Andy. “What do you want?” I mumbled.
“Shhhh. There’s a bear out there.”
I had not heard a sound other than Andy’s hissing, but we were camped in mountain bear country. “I don’t hear anything but you,” I said.
“There’s a bear out there, do something!”
Andy’s a bit excitable, but it wasn’t clear to me why he couldn’t “do something” about his alleged bear in the middle of the night. The two of us lay there for a few seconds listening intently. Then I heard the sound…
“That’s not a bear, you idiot, that’s Peter snoring in his tent. Shut up and go to sleep,” I grumbled, hoping to get more rest despite the wheezing and snorting in the next tent.
The story is absolutely true and I did not change names to protect the guilty. To be fair to my old pal Andy, bears tend to sneak into camp in the still of the night, using their acute sense of smell to sniff out sources of food. We were in black bear country but years earlier I had a close encounter with a grizzly bear just outside my tent in Glacier National Park, a truly sobering experience. We all carry vestiges of our cave ancestors in our sub-conscious memories so large predators like the bears still set our nerves jangling in a close encounter.
Ursus americanus, the American black bear, is native to North America and is found from coast to coast, from northern Canada into Mexico. It is a medium-sized bear by global standards but is smaller than our grizzly, brown and polar bears. While reclusive and rarely seen by most people, the black bear population is healthy and they number twice the combined population of the other bears. The total North American black bear population has been estimated between 340,000 and 465,000 animals. Black bears have a long history with fossil records of their ancestors dating back five million years. Small black bears in Asia are the closest relatives from a genetic standpoint.
Most bears prefer solitude over suburbia and need a mix of food sources to get through the year, with mast producing plants the most critical need (tree species such as oak, beech and apple). They are highly adaptable, living from sea level up to 10,000 feet in elevation. Omnivorous in their diet, bears are well equipped to forage for vegetarian foods or to hunt animals of all sizes from rodents to deer.
Powerfully built, black bears have short legs, wide feet that toe in slightly, and long claws for digging, grabbing prey, or fighting. Even a modest sized bear near our weight is far stronger than we are, having the capability of over-turning large boulders or logs weighing several hundred pounds. Their speed is deceptive since you would not expect an animal of their size and shape to be capable of running up to 40 miles per hour in short bursts. I once saw a large black bear in Alberta chasing a horse in a pasture and the horse was barely able to escape the charge by galloping flat out.
Bears are well equipped to survive in a harsh wilderness environment. While their eyesight is average for wildlife, they have wonderful hearing and one of the most sensitive noses in the animal kingdom. They are thought to be able to detect raw or decaying meat from as far as five miles. Bears can easily climb trees to take a nap or pursue prey, and they can swim long distances when they wish. In remote places bears are often diurnal (active mostly during the day) but when living near humans they become nocturnal.
Sows mature sexually at three years or older. Breeding occurs in the summer with males and females taking multiple partners. Large males become aggressive and battles over females in estrous can be ferocious. Gestation stretches to eight months because the fertilized eggs undergo delayed development and are not implanted in the womb until November. Birth takes place in the winter den when bears are in a state of deep sleep (torpor versus true hibernation) between mid-January and mid-February. A healthy sow can deliver as many as six cubs but two or three is more typical. At birth the cubs weigh less than one pound and are sightless, with their eyes opening around one month old. The cubs begin nursing in the den while their mother rests and may continue to nurse into early autumn. As with other large mammals, the juveniles will remain with their mothers until the year after their birth.
These great predators are mostly solitary except when breeding or rearing cubs. To protect large territories, the males travel regularly to mark trees around their boundaries by biting, clawing, or rubbing the bark to leave scent. Black bears are vocal, using a mix of grunts, moans and tongue clicks to communicate among themselves. When they become threatened or aggressive the bears will pop their jaws or exhale in loud huffs to warn intruders. If you hear a high-pitched bawl or squeal from a cub, you need to be on high alert for an angry sow nearby and do nothing that might escalate the situation. You may have come too close to the bears’ food source or you may be blocking their preferred path for travel. When disturbed by humans, black bears usually depart quietly so that you may not be aware how close you came to an encounter. But in rare cases, an adult bear may be too agitated to retreat.
The key is not to run as this might provoke a charge. Bear experts recommend standing quietly with your arms raised to present a large profile, while talking quietly. Often the bear will make a false charge or two to evaluate you as a threat. If you are attacked, lie down in the fetal position with your arms around your neck. Bear spray has proven to be the best defense against bears if they are truly threatening. Serious attacks on humans by black bears are extremely rare and almost always occur when a dog is involved or if a sow with cubs is disturbed or threatened. Well under 100 human fatalities from bear attacks have been recorded since 1900.
Thanks to recessive genes, black bears sometimes display different color phases. While black fur is nearly universal in Maine, black bears can be cinnamon, chocolate, blond and rarely, silvery blue. The prevalence of mutations differs widely by geography. Randy Cross, Maine Department of Inland Fisheries & Wildlife (IF&W) biologist, rated the chances of a chocolate-colored bear in our state at just one in 5,000. Across the country color phase bears occur around 30% of the time, with the highest incidence being in the Rocky Mountains.
Maine is well suited to black bears, with over 90% of the state in forest and low human densities in most areas. According to IF&W black bears gained steadily from an estimated 23,000 in 2004 to more than 36,000 in the last survey (2015). The population is now among the largest in the lower 48 states. IF&W reports around 500 complaints annually of human/bear conflicts, relatively low compared to other New England states. Those complaints most often involve bears attracted to back yards by bird feeders, messy grills, pet food or garbage cans. Bears can become habituated to humans and our homes as a source of food, and may become aggressive in periods when natural foods are less available. Black bears easily break into homes, garages, or vehicles in search of food and that may bring them close to humans, a troubling event for all concerned.
Most of the problems with bears occur in the spring after bears emerge from their dens. They lose 25-40% of their weight during winter, so finding food sources is critical. The bears seek out carrion such as winter-killed deer as an easy source of protein and fat. As spring arrives bears gorge on fresh green grass, sedges, and tree buds. In areas with white-tailed deer, elk or moose the bears compete with wolves and coyotes to find hidden fawns. As spring progresses into summer bears eat forbs, flowers, agricultural crops, eggs, nestlings, and insects. Bees are a favorite food and bears will go to great lengths to break open a hive, ignoring the stings to feast on the honey. In bear country it is recommended to remove bird feeders by mid-March and to rake up seed. My son ignored the advice this year and attracted a small bear to his yard one May morning. The bear pulled down the bird feeder and ate everything in the feeder and on the ground. After feeding the bear grabbed a nap in the landscaping and later returned to climb up on the deck furniture, perhaps thinking it was a good hang out!
Once natural foods become available the bears generally disappear from view through the summer months. Unless you come across a bear while picking blueberries or hiking through a brushy area where a bear is resting, you might think the bears have disappeared from the forest. But as summer turns into autumn the bears search constantly for high nutrient foods so they can pack on the pounds ahead of winter. In years when favorable weather results in good crops of nuts and berries all is well, but in drought conditions bears may once again move closer to settled areas. If a bear becomes accustomed to raiding homes and gardens, IF&W may be forced to capture the bear. Sometimes the bear can be relocated but often problem bears must be euthanized to prevent them returning to the scene.
Maine has an active monitoring and management program, a model for other states, having captured and tracked 3,000 bears over 45 years. With animals as large and secretive as the black bear, it is vital to have solid data about the health of the species to effectively manage the population in balance with public interests. Each year in March biologists use radio telemetry to find the dens of bears that have been collared or tagged with electronic devices. Crawling into the den to carefully remove cubs and smaller adults (after administering a sedative) the biologists will weigh and measure their subjects, sometimes taking blood samples for testing. Small, numbered ear tags are placed on each bear to aid in later identification.
By far the most effective wildlife management tool available to state biologists trying to keep the bear population in check is regulated hunting. The annual harvest varies widely due to weather and natural food availability but in average years around 2,500 bears are harvested, below the current birth rate. Hunting and trapping became topics of heated discussion in Maine when animal rights activists floated a referendum to dramatically reduce the harvest. Lost in that debate was the fact that the purchase of licenses/permits and hunting equipment provides a critical source of funding for the state’s management program. The federal Pittman-Robertson Act of 1937 created an 11% excise tax on the sale of firearms and ammunition, generating about $1 billion in funding for conservation and wildlife management efforts across the country. Some people are strongly opposed to hunting or trapping of bears but bears are a renewable resource, providing significant recreational and economic benefits in a state where hunting and trapping are deeply ingrained in our history and culture. If the harvest of black bears is significantly curtailed, the inevitable result will be an over-population of bears with a surge in bear/human conflicts that will not benefit the bears.
The largest black bear ever recorded in Maine weighed 699 pounds. New Brunswick recorded the largest one ever in North America, a monster approaching 1100 pounds! It would require decades to reach such size even in an area with plenty of food. Black bears are thought to average less than 20 years in the wild but captive bears have been documented up to 44 years old. As an apex predator black bears have few natural enemies once they reach full size. While small cubs may be snatched by bobcats, coyotes, or lynx, very few animals would dare to attack a mature black bear.
Native Americans actively hunted bears for their warm fur and nutritious meat, also using the rendered fat in making pemmican or as an insect repellent. Teeth and claws were used for necklaces and other decorations that indicated status or power. But the bears were respected for their strength and wisdom, seen as a creation of the Great Spirit to help the tribes. If you are lucky enough to see one of these animals moving silently through the forest it is a special experience. While black bears were long over-hunted and suffered from human disturbance in their native habitat, attitudes have changed with more scientific knowledge of the role bears play in a healthy, diverse ecosystem. Today their populations are stable or recovering in many areas, but it is up to us to preserve the wild places that creatures such as these bears need to thrive forever.
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