Part 5

Carnivores all, the animals on these pages illustrate various adaptations for capturing prey.

Protective Coloration

To escape extermination, each species must in some manner foil its enemies. Protective coloration is one of the more common adaptations helping to do this. Most animals resemble their environment to some extent. The conspicuous markings of some, like the bitter-tasting monarch butterfly or the striped skunk, seem to function as a warning to prospective predators that it is in their best interest to look elsewhere for a meal.

Some animals, such as the white-tailed ptarmigan and the snowshoe hare, have seasonal changes in plumage or pelage, wearing white in winter and brown in summer. Even predators, such as longtail and shorttail weasels, benefit from seasonal camouflage. Protective coloration makes them less noticeable to prey species and to larger predators.

Many insects, too, change coloration with the season. Bright green grasshoppers of early summer become more brown with each molt, matching the changes in the surrounding vegetation.

_Obliterative shading_ is especially important to animals that frequent more than one habitat. Seen from above, turtles match their dark background; from below, because of their lighter underbody shading they blend into the bright skylight.

_Disruptive coloration_ aids in breaking up an animal’s outline. Butterflies and moths commonly have disruptive wing markings. The distinctive shapes of eyes can be concealed. Eye coloration may mimic body color—as in the green katydid—or the eye may continue disruptive body markings.

Ground-nesting birds are especially vulnerable to attack. Their eggs tend to be heavily blotched with earthy colors, making them less conspicuous. Chicks also carry these disruptive colorations on natal down.

Most mammals, with coats of brown or gray, are inconspicuous when motionless. Deer fawns are endowed with speckled coats, mimicking the sun-flecked forest floor; this disruptive coloration, coupled with absence of scent and their instinctive “freezing” behavior, makes it difficult for predators to detect them.

The whitetail deer not only uses its white “flag” to warn others in the herd of danger; it also allows a pursuing predator to use it as a target. When the tail is suddenly dropped—abruptly obliterating the bright white patch—the deer seems to disappear into its dim surroundings.

Since overly conspicuous animals are prone to predation, natural selection favors development of appropriate camouflage.

_Ursus arctos horribilus_: The Vulnerable King

At the apex of the food pyramid, this great beast is unquestionably the king of Glacier’s biotic community. Yet the long-range future of the grizzly bear is uncertain. With the grizzly exterminated from most of its former range—which once extended into the midcontinent and south into Mexico—its numbers have dwindled in proportion to its diminished range. Present concentrations in the contiguous United States remain in and around Yellowstone and Glacier National Parks. Probably fewer than 200 of these magnificent creatures live in Glacier National Park.

Grizzlies are easily distinguished from the more common black bear. In addition to larger size and heavier build, grizzlies have a characteristic shoulder hump; long, conspicuous claws; and a broad, concave face that gives them a “dished-in” appearance. Fur is usually brown; like the fur of the black bear, however, color may range from black to yellowish. Light tipped hairs make the fur appear frosted, giving rise to the nickname, “silvertip.”

Grizzlies, popularly considered arch predators, are more accurately described as omnivores. Carrion, grasses, cow parsnip, and several species of berries, bulbs, and tubers make up a grizzly’s diet, along with insects, small mammals, and an occasional ungulate that it can catch. As a result, grizzlies play several roles in the biotic community, functioning as herbivore, scavenger, and predator.

Ranging widely in all life zones, grizzlies follow the spring snowmelt up to the alpine meadows, returning to lower elevations to hibernate from November until April. One to three cubs are born in midwinter during hibernation. Since the maternal bond lasts two years, a sow will accept a mate only every other year. Mortality of subadults is high, resulting principally from competition among the bears themselves. As with most animals, range—habitat—appears to be the limiting factor of grizzly populations.

The grizzly is normally shy and fearful of man—but highly unpredictable. Wounded or sick bears, sows defending cubs, young adults, and bears that have become conditioned to human scent are the most dangerous. As humans continue to encroach on grizzly territory, odds of confrontation also increase. Recent fatalities and personal injuries inflicted by grizzlies pose a vexing problem to the National Park Service, which is charged with visitor safety on the one hand and protection of the park’s remaining grizzly population on the other. Continuing study of grizzly ecology and increasingly enlightened bear management programs will, it is hoped, allow man and bear to co-exist in a wilderness both require.

Bald Eagles and Kokanee Salmon: A Recent Gathering

In 1916 the kokanee salmon, a small, land-locked form of the Pacific coast species, was planted in the Flathead drainage. With the first planting augmented by additional stockings, the fish thrived in cold, deep Flathead Lake, and, to a lesser extent, in Lake McDonald. The salmon fed almost exclusively on zooplankton.

By the mid-1930s, salmon runs were becoming established. The outlet of Lake McDonald provides an ideal spawning site for the salmon. The fast-flowing water is clear, cold, and shallow, and the creek bed is gravelly.

Averaging 0.3 meters in length and weighing less than a half-kilo, the 4-year-old adult salmon cease feeding and begin to migrate. Many thousands swim the 100 kilometers from Flathead Lake to McDonald Creek. Males appear in the creek first, arriving in late September, and are soon followed by the females.

Using her tail to dig a redd (a shallow nest depression), the female deposits about 650 eggs. After fertilization by the male, the eggs are covered over. The adults die within three weeks after spawning, their bodies exhausted from the rigorous migration journey and the weeks-long lack of sustenance.

Egg fatalities are high, due to stream erosion and disturbance by other spawning salmon. Hatching in late March, the fry work their way out of the gravel and migrate downstream.

Attracted to the 75,000-150,000 salmon concentrated in a 3-kilometer stretch of shallow water, bald eagles begin gathering at McDonald Creek in October. It is not known where the eagles come from or where they go after the spawning run. Glacier has fewer than 20 summer-resident bald eagles, and these are distributed among the remote lakes of the North Fork area.

In 1939, 37 bald eagles were counted along the creek. By 1969, 373 were reported, representing approximately 10 percent of that year’s estimated winter population for the contiguous United States. Since 1960, the count has averaged 240 birds. (In 1977 there were 444.)

Eagles feed by swooping down to pluck salmon from the water or by wading out to grab a fish stranded on a shallow riffle. An eagle may consume as many as six fish a day. Immature birds are not as adept at catching fish and may harry adults or other immatures into releasing their catch.

A Triumph of Many Colors

Grassland, meadow, tundra, or any other area in Glacier suitable for plant growth and supplied with abundant sunlight produces an extravagance of wildflowers. This display of various shapes and colors is neither an accident nor a mere decoration of nature. Nor would Earth’s recent explosion of mammal and bird species have been possible without the evolution of flowering plants.

Two hundred million years ago, early in the Age of Reptiles, angiosperms (flowering plants) had not yet evolved. Plant reproduction still relied on spores and cones. Then, during the Cretaceous Period, the last sediments were being laid down in the inland sea that covered most of Montana. (It was these sediments that the ancient Precambrian rocks of Glacier’s mountains later overrode, forming the Lewis Overthrust.) During this period the evolutionary miracle occurred: flowering plants—grasses, vines, shrubs, broadleaf trees, wildflowers—inherited the Earth.

The timing was important. As Earth’s tropical climate gradually changed to temperate extremes during this period, the domination of cold-blooded dinosaurs ended and the moisture-demanding coniferous forests that had covered the earth in green monotony began to shrink. Angiosperms provided a solution to the ecological void: grasses and forbs grew where trees no longer could. Most important, relationships evolved between this new class of plants and the relatively few species of insects then existing.

Insects began to use the pollen of flowering plants; the angiosperms, in turn, evolved bright petals and nectar that exploited visiting insects for the plants’ own reproductive purposes. This partnership allowed insects to diversify rapidly, evolving new, specialized forms such as bees, moths, and butterflies. As a result, predatory forms of insects and arachnids also rapidly diversified.

The most dramatic change, however, involved warm-blooded birds and mammals, whose high rates of metabolism required high-energy fuels. Unlike gymnosperm seeds, which contain no protective covering, angiosperm seeds are surrounded by a fruit. The development of these highly nutritious seeds, and the attendant explosion of insect species, ensured survival of the newly evolved birds.

As birds diversified into seed-eaters, insectivores, and carnivores, mammals, then uncertain little ratlike creatures darting among the feet of dinosaurs, began a rapid rise to dominance; grasslands promoted an explosion of herbivorous and carnivorous species.

The evolution of angiosperms, and the animal revolution it made possible, came with amazing speed. Most significant, it was a vital first step upon which the meteoric rise of man depended.

Fire Succession: Key to Continuity

Most of Glacier’s fires are lightning-caused. Strikes may flare up immediately; or fires may smolder in the forest duff for days until fanned into flame by wind. _Ground fires_ may race through the forest understory, causing minor damage; or they may bridge the understory and reach the canopy, thus becoming rapidly spreading _crown fires_. Under certain conditions, uncontrollable infernos may develop, generating terrific winds and heat. These rare conflagrations are called _fire storms_.

Every type of forest habitat has _climax vegetation_—trees and shrubs that are best suited to the site and thus maintain themselves indefinitely if not disrupted.

After a major fire, habitat conditions are usually so altered that the site must pass through several _seral stages_ before conditions are such that climax vegetation can return. A _sere_ is a series of plant communities that follow one another in orderly fashion until climax conditions are again reached.

Sudden hammering made me jump. Above the forest darkness, a pileated woodpecker leaned out from a high larch snag, braced against the trunk by its specialized, stiff tail feathers. This was the first time I had seen this big white-and-black bird, the “cock-of-the-woods.” There was ample evidence of his work: the deep, oblong excavations in the trunk and the pile of large wood chips at its base, both characteristic of this species. Again he hammered, and I could see the chips falling. After a little edge-work around the hole, he extracted a grub and flew off, yammering against the advancing dark.

Near a stream I stopped to sit down, to listen to the water and maybe catch sight of some small animal. Across the narrow defile, from a slope dense with young hemlock, came the buzzing note of a varied thrush. Several notes followed, all on a different pitch, all drawn out, level and clear; the quality was pure but songless, disjointed, deliberate, like someone testing the reed of a strange woodwind. There seemed no gladness in the heart of this thrush. The song was dark, haunting, lonely.

On the trail ahead I could make out a bird hopping rapidly along. After passing the spot I could hear its song. There couldn’t be a hundred meters between us, yet it seemed to be coming from a great distance. I listened for as long as it would sing. I tried to hear it for what it was, a male Swainson’s thrush proclaiming its territory. But the ethereal, flute-like phrases seemed an evensong made not for man’s ears but only for the forest itself.

I hurried on after the bird had ceased. It was getting dark beneath the trees, but I was beginning to be aware of creatures underfoot, the mad dartings of shrew and vole, more imagined than seen. When a deer mouse jumped away I got out my flashlight. Soon the beam caught a woodrat sitting atop a fallen log. The light didn’t bother him in the least; as I approached, he picked up his bushy tail in his forepaws. Whiskers twitching, he looked more caricature than real. Then he bounded off the log with graceful, arching hops, and disappeared into the night.

Against a patch of sky that appeared in a clearing, I could make out bats, circling and dipping like swallows. Locating a hovering moth, I kept the light beam on it until it vanished into a furry streak of silence. It was time to head back.

By now it had become utterly dark within the trees, a moonless, sightless, alien world, given over to the marble-black eyes of the small night mammals and the creatures that hunt them. I thought of the strange, unseen societies of the flying squirrels, the nocturnal counterparts of red squirrels; of the great-horned owls, inspecting the same ground the goshawks scanned during the day. Perhaps a foraging red fox moved through the darkness nearby, or a coyote on night patrol.

The flashlight beam probed ahead along the trail. The exposed roots were given unnatural shading and they seemed to thicken and squirm as I approached. On either side the tree trunks appeared to step backward from the dim glow of the light. I felt lost in this night, thinking of the great darkness in all the timbered ridges that ran westward from the Divide. In this vast cathedral of crowded tree and peak, night was stood on end, the stars shrunken to a circle overhead, as if seen from the bottom of a well. Mouselike, shivering, insignificant in this wilderness, I scurried back to find a fire and fill my empty senses with its heat and snap and light, holding off the fright of night and thinking of tomorrow’s sun.

Scrub-Forest

The crowning beauty of Glacier—the high, cirqueheld meadows that scent the wind with wildflower and waterfall—belongs to the zone of scrub-forest.

At Logan Pass you are introduced to the highlands. Here an exquisite upland basin holds the Hanging Gardens, a wildflower-clothed gradient laced with stair-step bogs and lines of wind-bent subalpine fir. In the dawn sun, before the first engine noise, it shines unbroken, dewbright and sagging like a spider web secured to the circle of surrounding peaks.

This is the region the hiker remembers best. The tall mountains wear this zone close to the cliffs, and the trails encounter it near the passes or follow it for long, level stretches, as along the Garden Wall. I remember Preston Park and Fifty Mountain, the fire-touched bench of Granite Park and the first sight of Sperry chalet, built on a brow of rock at the upper reach of trees. But most of all I remember the terrible waterfall that becomes Bowman Creek, the plunge of nearly a kilometer that drains the magnificent upland bench called Hole-in-the-Wall.

Hole-in-the-Wall

September. The season is growing late, the meadow-rue dying and the leaves of the wild strawberry failing at last. Everywhere the red contagion of autumn surrounds the vital green. The lower valleys have lost the whistle of ground squirrels. They sun themselves no longer these late, mild days. Ripe, sluggish, and hawk-vulnerable, they sensed the need of hibernation.

It has been eight years since I last visited Hole-in-the-Wall, but I retain its dimensions and hear its dozen waterfalls at will. Once you have seen this basin you have a measure by which to judge the high country and a thirst for the meadows at tree-line.

In Glacier, treelimit ranges between 1,850 and 2,300 meters, depending on local conditions. The upper limit of tree growth—rarely an even, horizontal line—is generally an indistinct band running erratically across a mountain’s face: a tension zone reflecting variations in wind and sun exposure, degree of slope, snowpack accumulations, and the presence of adequate soil and water.

Subalpine fir, whitebark pine, and Engelmann spruce do not relinquish easily their upward climb; where conditions become severe, their growth is retarded and their stature dwarfed. Deformed and pruned by wind, their leaders winter-killed when they outreach the protection of the winter snowpack, trees become shrubs, forced to hug the ground. Size belies age in these elfin forests, or krummholz, where the growing season is painfully brief and progress is always uncertain. A twisted, gnarled little bush, more snag than live branch, bearing a single cone or two, may be senior by a century to the giants of its race in the valley below, which yearly shower the ground with an abundant crop of cones.

This time I will come from Goathaunt, passing Lakes Janet and Francis, reaching Brown Pass from the east, and camp in the spectacular garden between Brown and Boulder Passes.