A grizzly rubs against a tree at Brooks Falls, Katmai National Park. Courtesy Bernard Marschner.
Like people, bears, though engrained opportunists, are creatures of habit. Over decades and sometimes centuries, generations of them commute to and from work—their work being fishing and grubbing, napping, mating, putting on pounds for winter, fighting rivals, dodging hunters, and caring for cubs. Literal ruts, their pigeon-toed routines are rarer and longer lasting than tracks.
On St. Matthew Island, a lone, green blip on the Bering Sea’s gray screen, polar bears formerly summered “lazily sleeping in grassy hollows” when not “browsing like hogs.” A biologist thought circa 250 lived there, apparently in fine condition. By 1899, after sealer and revenue-cutter crew visits, only grooves in the tundra remained.
Bears pad on intimate alleys through muskeg or northern rainforest tangles. Soft-shod like we, they mosey down deer trails and dirt roads. They skirt wetland meadows, truckin’ between trees where soil is firmer and forage better. They trundle across scree slopes, enticed into valleys by hunger and memories. They ford rivers, balance on logs above streams. Do they contemplate shortcuts? Plan rest stops? Switch to cruise control? Follow mental maps, favor faster lanes, or feel traffic has gotten worse? Their Local Positioning Systems process whiffs, sounds, visual clues. During salmon runs, they stitch waterways into arcane rounds, surprising bipedal berry pickers and anglers. It pays to be mindful traipsing along brushland meanders, more so at dusk, grizzly rush hour.
Post-holing in marshes or ankle-deep moss, bears using each other’s imprints save energy. In difficult terrain, bears step in “direct register” to save energy, placing a rear foot in the track left by the front foot, which further defines connectors in home ranges as a rule undefended. Over time, parallel lines of pits form, offset like zipper teeth. These are awkward for hikers, since grizzlies have broader shoulders and hips.
Conveying facts less glaring to us, paw glands alert passers-by with noses shaming those of hounds. Adept pheromone sniffers, dispersed polar bear males thus latch onto receptive females in sea-ice expanses. Their bruin cousins “stomp-walk,” especially in the breeding months, pissing purposely and then grinding their scent into the earth, as if squashing bugs or foes. Such “mark trails” show clearly near prominent trees against which bears rub not to scratch but to impart skin odors and anal secretions, olfactory fingerprints. Boulders or Park Service signs make handy message boards—perfume notes of 20 distinct compounds curb brawling by establishing hierarchies. The where, when, how much, and how often of chemical Post-Its with aromas far from subtle differ according to sex and age. Gauze on trees the state biologist Anthony Cupri preps turns almost black from oils and dirt in the fur and “really smells like bear.”
Hair that researchers gather from bark and wire snares for genetic analyses reveals the sex, numbers, and relatedness of bears in a given place. Grizzlies and black bears have favorite trees, ursine chat rooms, where ranges overlap. They mangle rows flanking travel corridors too. Trunks fiercely bitten bleed sap. Curved claws scar them with extra hormonal graffiti. “I’m yay tall, sucker!” the initials proclaim not just to wary backpackers. In addition, they might be waypoints, milestone tree-blazes in unknown country.
Though bear agendas web wilderness largely unseen, evidence helps you dodge trouble: a field cratered not by backhoe or carpet-bombing but by Griz craving ground-squirrel snacks; scat like horse dung, unmistakably coarse with caribou hair or grass roughage or pebbled and purpled by berries, depending on the season. Its freshness dates a bear’s passage. Do not camp anywhere near.
A honeycomb maze scores a lodge’s environs and the banks at Katmai National Park’s Brooks Falls, a world-famous fishing spot drawing bears bumper-to-bumper. Boardwalks to viewing platforms separate tourists from hermits briefly social at ground level—ideally. The bear enthusiast Timothy Treadwell, belying his surname, camped weeks on end over 13 summers in Katmai’s backcountry among brown bear day beds and food sources yards from intersections of tunnels in alder thickets through which they swaggered but which forced him to crawl. In 2003, this intimacy proved fatal. A rogue silvertip mauled Treadwell and his girlfriend whose death sounds their dropped video camera captured.
Even encounters on city or suburban park paths cause incidents. Joggers and bikers blinkered by headphones or speed trigger chase instincts. In the Big Race not the quickest or fittest but the most attentive survive. At least 20 grizzlies in Anchorage’s Far North Bicentennial Park are busiest from July to early September. Municipalities warn recreationists most active on mild weekends during that window. While bears park their butts, feasting on moose or caribou, land managers may shut down trails to prevent dinnertime human drop-ins at kills or scavenging sites. As a last resort, wildlife cops haze, tail, or kill “problem” bears. We should yield bears the right of way. We’re exercising. They are at work.