A Home for Wildlife
Some animals indigenous to the Great Plains find a protected home in Devils Tower National Monument. Gone from this area are the bison that once roamed the prairie grasslands in great numbers, and the fastest plains animal, the pronghorn antelope, is rare. The most noticeable mammals here are the whitetail deer and the prairie dog (See pages [48]-65 for pictures and text about the prairie dog and its predators), but with careful observation you can spot some of the smaller animals that inhabit the grasslands, woodlands, and rocky areas around the Tower.
The raccoon, primarily a nocturnal creature, prefers woody or swampy areas and often dens in hollow trees.
The porcupine, which has up to 30,000 quills, dwells in the forest and often is seen in the tops of trees.
The longtail weasel usually lives in deserted burrows and preys on small mammals, some birds, and other animals.
The rare swift fox sometimes enlarges and inhabits an old prairie dog burrow. The red fox is more common here.
The pocket gopher is a remarkable burrower, creating up to 150 meters (500 feet) of tunnels close to the surface.
The thirteen-lined ground squirrel lives in a burrow in open areas, feeding mostly on seeds.
Whitetail deer mostly inhabit wooded areas in the park, though you may see them in clearings. Often they wander into the campground near the Belle Fourche River at dawn and dusk, providing an added treat to those who spend a night or two in the park. Deer usually do not go beyond an area of 4 square kilometers (1.5 square miles) even when their food sources are limited. They are browsers, eating all foliage they can reach standing on their hind legs. So, you may notice most foliage denuded to a 1-meter (3-foot) level, especially where their populations are high.
Whitetail deer can run 56 kilometers (35 miles) per hour, jump 2.7 meters (8.5 feet) high, and leap about 9 meters (30 feet), all quite gracefully.
Now, after 80 years of fire-prevention management, the forest is ripe for fire. Should it come now, however, the effects might be devastating. Fed by an abundance of ground fuel, a cool-burning, fast-moving grass fire could quickly become “hot.” Lifted up into the upper branches of the old pines via the closely spaced younger trees, the ground fire would quickly develop into a crown fire. Few, if any, trees would survive such a conflagration.
The role of natural fire has only recently been appreciated. However, in the small area of Devils Tower, where the scenic qualities of the pine forest are paramount to visitor enjoyment of the Monument, fire cannot be permitted without virtual destruction of the surrounding forest. Thus, for esthetic reasons, fire is regarded as unacceptable here.
After lunch I walk on beneath the trees. The openness of the mature pine forest soon gives way to dense groves of younger ponderosa. Deprived of the separation they require to develop naturally, these “doghair” stands strain upward together their trunks toothpick thin—to reach the light. Many exhibit long, yellow wounds, from which sap bleeds. This is the work of porcupines. Gnawing through the thin bark of young trees with sharp, chisel-shaped teeth, they strip away the tender, living tissue of the tree. Most wounds are not severe, but should the trunk be girdled, the moisture and nutrient transport system of the tree will be severed and the pine will die. Thus, even though fire no longer occurs here regularly, other agents of control, such as porcupine damage and insect infestation, continue to work.
The trail emerges from the deep north-slope forest, runs parallel to the visitor center access road for a short distance, and ends at the parking lot. The glare of afternoon light and shimmering heat waves is a sharp contrast to the cool, dim surroundings of the deeper forest.
Before continuing on around the circuit of Tower Trail, I stop at the visitor center for water. Beside the fountain sits an old man, leaning his chin and hands on a cane and staring upward at the broad west face of the Tower. An immense mushroom of a towering cumulus cloud billows up behind it.
“Quite a sight,” I say.
He seems to deliberate, then finally answers: “I can remember seeing a picture of this in my school book. I never thought I would live to see it. Never thought I would ever sit here like this and see it genuine.”
I don’t know what to say. One does not make idle conversation with a man who has made a pilgrimage. We watch a pair of rock doves, outlined against the white brilliance of the boiling cloud, ride an updraft near the summit. Wings set and almost touching, they dip and recover, their resonant calls clear despite the distance. Nothing more to be said, I set out toward the trail. Not once did the man take his eyes off the Tower.
With the first dull report of thunder, I hear the chiding call of the falcon again. Its sharp voice momentarily silences the mellow cooings of rock doves that filter down from the high crannies and ledges.
The trail steeply ascends a slope of broken, fallen columns, weaving among the immense rock slabs like a mouse-run in a boulder field. I am surprised to see a grove of aspens. Their crooked trunks bend in the freshening wind, their leaves dancing and blinking on and off the dusty silver of their undersides. What a contrast to the rigid stature of the surrounding pines that barely acknowledge the approaching storm.
The presence of aspen probably means that a fire once swept across this dry western shoulder. Quick to invade new territory after a fire, aspens play an important role as a pioneer species of the western and northern American coniferous forests. Like the ponderosa, they can grow on dry, rocky sites. Since they often reproduce vegetatively—a grove of aspens is often produced by sprouting from the roots of a single tree—aspens are well suited to unstable or fire-swept sites. Although readily consumed by fire, aspen groves regenerate quickly from their undamaged root systems. Without periodic fire, in fact, aspens are eventually excluded from the forest composition, shaded out by the taller growing conifers.
The growing turbulence spurs me onward. Hugging the steep upper slopes of the Tower’s circular base, the trail allows a speedy orbit. The falcon continues to scream. Now along the southeastern face, I can hear the climbers shout to one another. The belly of the cloud is overhead and angry-black. Lightning flashes are now immediately followed by loud reports, sharp as splitting wood. I should turn back and drop to the nearby trail that returns to the campground, but the swell of wind in the pines and the occasional crash of falling snags is invigorating. A sudden invasion of cold air means the rain will come heavy and soon. I wonder if the climbers are as unprepared for this as I am.
In a rock crevice where the trail passes along a cliff face, an untidy ring of trash reveals the nest site of a wood rat. Called “pack rats” because of their habit of carrying off unguarded items, these big rodents adorn their nest entrances with anything from bottle caps to sunglasses. This one has amassed a fine collection of discarded gum and candy wrappers. As the first large raindrops thud down into the trail’s soft earth, I envy the animal’s protective retreat.
In ten minutes I am back at the spur that leads to the Visitor Center. If the old man is still there, perhaps I will wait out the storm with him beneath the porch roof. But I cannot see him, so I continue on to the campground. I am already soaked through anyway, so the lashing rain is no longer a threat. I retrace the section of trail I had walked an hour before. Ten minutes more and I leave the pines and enter the deserted, puddled prairie dog town.
Nearing the road, I see a car approaching slowly. As it passes I notice the old man. Leaning forward, he cranes his neck to catch a last glimpse of the Tower he had waited so long to see.
Voice of the Kingfisher
By late afternoon the storm has passed, and with the return of sunlight a rainbow arches the Belle Fourche. Taking advantage of the softened earth, the prairie dogs busily reshape their mounds, scratching dirt loose, bulldozing it up the slopes of entrance mounds, and tamping it. All but the young wear black noses. At the return of the climbers the town suspends its work, rises to alert, and chirps warning.
A meadowlark sings from a fence post near the river. Against the purple southern sky, its black and yellow vestments seem unnaturally bright, and its call in the rain-cleared air seems sharply amplified. It glides into the glistening grass. Soon the female, wearing a duller version of its mate’s tuxedo, flies up and disappears across the narrow river. When she returns, her bill is crammed with insects for her demanding young in their grass-lined ground nest.
A red-headed woodpecker, which has been shuttling between a certain cottonwood and other trees, also reveals its nest site. High up in the tree it has excavated a perfectly round hole. Leaning back on stiff tail feathers, it jerkily climbs up and around the trunk, pauses at the hole, then leans in to deliver the white grub to its squealing young.
So insatiable are nestling birds, their demands exert a significant control on insect populations. A pair of adult house wrens may log more than 1,100 daily trips to feed their young.
That so many varieties of birds can co-exist in the same area is possible because different species generally do not compete with one another for the same food source. Each gleans its food in a slightly different manner and locale. Each species vigorously defends its territory from others of its kind but will tolerate neighbors that occupy a different niche in the community. A single plum thicket may contain the nests of a pair of catbirds, mourning doves, robins, and vireos. Because each bird hunts its food in a slightly different manner and place, they do not directly compete.
The cliff-nesting swifts and swallows have reappeared above the river, a twittering confusion of swirling, darting shapes that manage to survive by capturing insects on the wing. Higher up, the booming of nighthawks announces that insects are active in the upper air also.
After supper I walk along the river. Now that shadows fill the river bed, there might be an opportunity to see a beaver working or a mink hunting along the shore. Passing close to where the meadowlarks have their nest, I cause a panic of concern. Both birds, invisible a second ago, lift off the ground, scolding and threatening, to distract my attention from the location of the nest. The outcry brings a killdeer up from the shore of the river. Uttering its plaintive, reedy cry, it circles about, lands, runs rapidly along the bank, then crouches down to display a “broken” wing. It is joined by a mate and both birds take up the act, leading me away from their own eggs or helpless young hiding motionless on the ground. So adept are the killdeer at this diversion, it seems incredible that instinct and not intelligence is responsible for their highly specialized behavior.
continues on [page 46]