The scene reveals just one of many dramatic behavioral changes for the Yellowstone-area grizzlies. Only a generation ago, they were scooping half-eaten hot dogs and stale Twinkies from garbage piles in the park. But now Steven and Marilynn French, two self-trained bear researchers, have chronicled what they call “an important step back” for the Yellowstone grizzly -back to ancestral habits that experts thought had been lost forever. The work has opened a new window onto animal behavior and its evolution. It has forced ethologists to rethink how human activity affects animals’ feeding, mating and other habits and how quickly changes in those behaviors occur. Most intriguing, it raises the question of whether it is an atavistic memory for ancient ways or a relearning of old tricks that compels grizzlies to take up behaviors that had seemingly vanished from their repertoire.
To reach the grizzly’s unlikely summertime haunts, you have to climb out of the sage and cottonwoods, through forests of lodgepole pines, up to the last stand of craggy subalpine firs at about 10,000 feet. There, a few canvas tents serve as base camp for the Frenches, who support their bear research through the nonprofit Yellowstone Grizzly Foundation and by working half the year in an Evanston, Wyo., hospital (Steven, 45, is an emergency-room physician and Marilynn, 40, a nurse). At 4:30, before the first rays of dawn pierce the ridges to the east, the Frenches climb 1,600 feet to a wind-swept overlook, a comforting half mile from where the bears feed. For the rest of the day, they scan through binoculars and spotting scopes, scribbling with hands so cold that their writing is barely legible. Besides mapping moth sites-areas of an acre or so, usually in glaciercrushed rock-the Frenches note such behaviors as female grizzlies with cubs confronting males: the males often back down, suggesting that their dominance does not go unquestioned. The researchers have also recorded one grizzly family feeding near another, dispelling the idea that the bears have little social interaction.
Although outfitters had occasionally reported bears eating “bugs,” no one had appreciated how important moths could be to grizzlies. The Frenches have observed more than 100 bears for whom moths serve as a major summer food source. The moths, natives of the Great Plains, migrate to the mountains in summer to feed on the nectar of alpine flowers by night and to cluster in the cool, protected rock formations by day. Improbable as it sounds, moths are a perfect food for the bears during the critical summer, when they put on fat for winter hibernation. Composed of 72 percent fat and 28 percent protein, these flitting morsels are a better energy source, ounce for ounce, than deer meat or cutthroat trout. Of course, it takes a lot of moth wings to see a grizzly through winter. But the bears can consume hundreds of thousands of moths per year, the Frenches find, by feeding six hours a day for a month or more.
By the time the Frenches began researching grizzlies, in 1983, the great bear had gotten in the way of too many Winchesters. Some 50,000 grizzly bears once roamed the Lower 48 (before they were the Lower 48); probably fewer than 1,000 remain today. Even in Yellowstone, the grizzly was almost lost in the early 1970s, after the park closed what had been a staple food supply for more than 80 years: open dumps containing up to 4,800 tons per year of discarded sandwiches, chips, marshmallows and other garbage left behind by park visitors. Many bears had forgotten how to get food any other way. With park garbage sites closed, the bears ambled into dumps in towns surrounding Yellowstone; scores were killed by terrified residents. By 1975, the U.S. Fish and Wildlife Service had listed the grizzly bear as threatened, meaning that the population faced extinction. Many researchers doubted the species would ever recover.
The park service counterattacked. Yellowstone elk herds that had been periodically “culled” were left alone and proliferated. New catch-and-release fishing rules filled streams with cutthroat trout. Certain valleys were sealed off from tourists during the crucial elk-calving and cutthroat spawning seasons.
What happened next was a crash course in Darwinism–call it devolution. In just one generation, grizzlies relearned predatory behavior. They became adept at swiping 100 trout a day from streams; they stalked elk calves with the hunting instinct of a Serengeti lion. They foraged for seasonal plants like biscuit-root and sweet cicely. They roamed alpine areas to feed on moths. While other researchers had deduced some of this behavior, the Frenches saw it firsthand-and filmed scenes that stunned even veteran researchers.
But how did the slovenly garbage bears figure out that trout or moths were a tasty substitute for moldering Devil Dogs? Did they draw on some collective bear unconscious to find moth sites and spawning streams, much as migratory birds manage to fly to wintering grounds they have never seen? Or were the grizzlies merely driven by hunger to any available food? “You could debate all day long,” says Steven French, who prefers a middle ground in the nature vs. nurture face-off. He says the omnivorous grizzly is simply good at adapting to changing conditions. The bears forage constantly in order to sample new foods-behavior ingrained since the last ice age. But French is convinced that grizzlies can also learn without prior experience-that is, figure it out for themselves. “When we watch them, we just have the sense of a thinking animal,” he says.
However the bears relearned their old survival skills, the Yellowstone population is doing better than it has in decades. “We’re having a grizzly-bear boom,” says Marilynn French. But since a male grizzly can roam more than 1,500 square miles, she says, “the boom’s not going to last if we keep destroying grizzly habitat.” That’s a real danger. More than half the grizzly’s Yellowstone stomping grounds lies outside the protection of the park, mostly on National Forest Service land. There, the government has for years backed timber and mining interests that want to keep public lands open to development. The Endangered Species Act, which requires that habitat be managed in a way that will bring a threatened species back from the brink of extinction, may be no match for that pressure. The federal government has designated seven grizzly-bear “recovery zones” (map), ecosystems that it will try to preserve in order to increase the grizzly populations. But already the Canadian mining company Noranda, Inc., is eying a gold mine, which may contain $680 million worth of ore, in the Yellowstone recovery zone. The grizzly has survived so far by deftly adapting to its changing environment, but if there’s no environment left to adapt to, the great bear simply won’t make it.
Bear Necessities: The federal government is trying to preserve crucial grizzly habitat in seven ‘recovery zones.’
