Photo by Valerie/ucumari on Flickr (Creative Commons BY-NC-ND)
On a warm, humid day in late May, I climbed up Pit Mound Trail to the top of Sapsucker Ridge and followed the old logging road along the ridgetop.
As I reached a foot trail into the forest, a medium-sized black bear burst from the underbrush and ran full-tilt toward me.
“Hey there,” I said. It stopped, looked at me, turned, and ran downhill. As usual, my close encounter with a bear—a mere 30 feet away—was so peaceful that my heart rate didn’t even increase.
Over the years I have had numerous close encounters with black bears, and not once have I felt threatened. That is as it should be according to black bear researcher Benjamin Kilham. He has been studying black bears in the field and raising orphaned cubs at the behest of the New Hampshire Fish and Game Department for nearly two decades.
In his excellent, new book, Out on a Limb, Kilham advises us to stand still, look at bears and speak quietly to them. In almost all cases the worse they will do is false charge.
But if you feed bears, either intentionally or unintentionally, with bird feeders, they quickly become habituated, and you must continue or they may come into your home in search of food. Kilham feels that “nuisance bears” have become so because humans feed them. We learned that lesson when they came on our back porch and turned over metal garbage cans filled with washed cans and bottles for recycling and with birdseed. Once we put those cans in our basement and brought our bird feeders in at night, we had no more bears tramping around on our porch or peering into our bow windows.
Black bears live in a world of scent, Kilham says, and they can smell food from a distance. Especially when wild food is scarce, as it has been our last three autumns without a good acorn crop, bears are on the lookout for black oil sunflower seeds which give them more nutrition than any wild foods available to them.
But they also use scent to track down each other, identify bears in the vicinity, and follow bears that have found surplus food. Their sweat glands excrete alarm scents when they sense predators, such as coyotes. If they are extremely frightened, they emit scent from their anal glands which brings other bears to their rescue.
They leave scent marks on trees along with claw and bite marks. In New Hampshire, where Kilham lives, they favor red pines. On our mountain they use the power poles on our small powerline right-of-way.
The day before I ran into the bear, I was crossing the right-of-way on Laurel Ridge and looked 1900 feet across at Sapsucker Ridge. I spotted a round, black object beneath a power pole. At first I thought it was a shadow, but when I looked through my binoculars I saw a very large black bear nosing around. Then he ambled off toward the vernal pond area.
Later, when I examined the pole, I found it had been shredded as high as seven feet. Probably the bear was a male signaling his availability to local females. Both sexes will back-rub, side-rub, and chin-rub such trees too. They also walk over saplings or crawl under them to leave their sent or mark with their scat or urine.
black bear-marked power pole in Plummer’s Hollow (photo by Dave Bonta)
Using radio collars, remote cameras and DNA testing, but most of all his own observations, Kilham has found that other bears not only know the identities of the marking bears but also their gender, mood, relationship to them, and where they stand in the social hierarchy. In his area, females have a core home range from three to five square miles and a dominant female ensures that her daughters and granddaughters set up nearby so she can control an even larger area.
Male cubs are sent on their way at 12 to 18 months of age to live wandering lives, usually in bands of other subadult males so they can overpower females and get access to food. But adult male bears don’t compete with females for space, cover, or water because they are hoping to mate with them. Instead, they wander as far as 200 square miles a year in search of food.
On the other hand, overlapping female home ranges may also be the home ranges of several breeding males, but often only one dominant male will mate with the females in his breeding area. Kilham estimates that only the largest males age eight or older get to mate—10 to 15% of the population–even though males are sexually mature at age two.
In addition to scent, bears communicate through facial expressions, ear movements, body posture (like their stiff-legged walk to intimidate other bears) and vocalizations. The bear I encountered looked startled and Kilham says by studying bears closely, especially some of the cubs he’s raised to adulthood and then continued to observe closely throughout their lives, he has “found a great deal of similarity between human facial expressions and those of bears…Smiles are smiles and frowns are frowns.”
Furthermore, if a bear’s eyes twitch or its ears are cocked back, it is annoyed and deciding what to do. When it is irritated, its ears are half-cocked. If a bear is being cautious but curious it may have one ear cocked forward and one backward.
Black bear vocalizations include what Kilham calls a “guttural reverberation of sound in their chests” when they are angry and as well as a “huh huh” when they are upset and an “mmm, mmm,” appeasement call. They also make a gulping sound that males use to get female bears to go with them during mating season and females use to guide their cubs and keep them safe.
Black bear mother with cubs in Plummer’s Hollow (photo by Dave Bonta)
When cubs are nursing, they make a “deep loud purr” which they also make when they are happy. They have a loud distress call that Kilham says sounds like “Baa Wo Oow,” but I thought was a wailing child. Years ago I heard such a sound one fall morning and then saw two cubs below our house crying while standing over something black. When I rushed down, they ran off still yowling. There on the ground was a dead adult bear. She had been shot out of season with an arrow somewhere on our mountain and had managed to reach our yard before dying or so the game protector we called told us. He took her away, but I will never forget the sound those cubs made.
I often wondered if the cubs survived on their own. They would have been born the previous January and their mother would have begun teaching them about food sources once they had emerged from their den in the spring. Kilham discovered that they learn by mouthing and smelling what their mother eats– buds, young leaves and flowers of trees, especially red maples and white ashes, in spring as well as wildflowers such as nodding sedge, jewelweed, wild lettuce, and especially jack-in-the-pulpit, in summer berries of all kinds, and in autumn acorns and beechnuts. In all three seasons they devour ants, bees, and grubs. One of Kilham’s cubs, Squirty, ate 40 to 60 ant nests in an hour while another, Yoda, consumed 20 to 30 yellow jacket nests. They are also opportunists and will take newborn fawns and young nestlings and fledglings. A Pennsylvania Game Commission study found that they were a major predator on fawns.
Black bear enjoying a foggy day by Howard Ignatius (CC BY-NC-ND)
Because Kilham suffers from severe dyslexia, he is not a trained biologist. Instead, he makes his living as a gunsmith. Yet year after year, he goes into the woods to watch bears. Through various experiments he has found that bears use fresh ungulate scats as probiotics and that they can learn to recognize themselves in mirrors. He also discovered what is now called the Kilham organ by noticing that the cubs he raised mouthed all new-to-them vegetation, often holding it in their mouths for a few seconds and then releasing it unmarked. He dissected a road-killed bear and found a fleshy organ about jelly bean-sized in the pocket of a V-shaped bone, called the vomer, which is under the center of the nose and above the palate. Eventually, after years of research, he realized that sensory nerves in the organ allowed them to identify airborne scent with it. They also use it to figure out what is safe to eat.
At a lecture he gave at the College of the Atlantic (which I watched on YouTube), someone asked him why he studied bears. His answer was that “We need to know more about the animals we exist with.” And, as he says in his book, “You don’t need to be a credentialed scientist to make new discoveries. You just need to go outside and open your eyes.”