This small area of grassland, sandwiched between the base of the Tower and the encircling river, supports a surprising amount of life. Yet from all appearances, it would seem as if the multitude of prairie dogs would soon denude their patch of land and die of starvation. In contrast to the surrounding territory, the vegetation of the dog town appears exhausted.
Indeed, today’s empty plains give few hints of what a crowded stage the shortgrass plains once was. Before the coming of the white man, the grasslands teemed with bison, pronghorn, wapiti—named buffalo, antelope, and elk respectively by European settlers—and sprawling towns of prairie dogs. Astounded early observers, accustomed to the lush flora of the eastern woodlands, could not imagine how so many animals could survive in such a parched-looking land.
The secret is the grass itself. Whether tinder dry in midsummer or dead in winter, the grass blades remain highly nutritious. Grass plants can withstand repeated grazing and fires since new growth progresses from the stem joints rather than from the tips.
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A Glimpse of Life on the Top
Photographer Galen Rowell and writer Dennis Hanson decided to climb the Tower in October 1978 to find out for themselves what’s up there. After a strenuous five-hour climb, interrupted by occasional clouds of rock doves (below), they reached the top and found the surface is not as flat as it appears from down below or even from an airplane. Besides grasses, they found sagebrush, currant, and prickly pear cactus (below). As they were cooking dinner, a wood rat (below) joined them, nibbling at their food packets, peering into a pot, and nosing about their climbing gear. They also saw chipmunks and plenty of birds (See pages [44]-45, [60]-61), but, perhaps because of the coolness of October, they did not see any rattlesnakes, which others have found there sometimes. How did the animals get to the top? Some people have speculated that they were dropped by predatory birds, but that is questionable: they probably would have been killed by the birds’ talons or by the plunge to the surface. More than likely they just climbed up the Tower’s sides and took up residence. Many climbers, of the human sort, have reported seeing snakes and rodents working their way up fissures.
What’s on top of the Tower? Most climbers report that the summit is similar to the surrounding landscape. Grasses cover much of the rocky surface, but better than that, a few snakes and mammals live there!
Wood rat.
Prickly pear cactus.
Rock doves.
In addition, most plains animals contend with the semi-arid conditions of their environment by making efficient use of available moisture. Pronghorn, prairie dogs, and kangaroo rats, for example, need never take a drink since they obtain necessary water from the plants they eat. Such plant and animal adaptations explain why the shortgrass plains can sustain such a vast panorama of life.
From a tall pine upslope, a red squirrel chatters with indignation at discovering my intrusion into its domain. The bell-like song of a rock wren answers from an outcrop nearby. The small gray bird appears atop a boulder, motionless but for an instant, then hops down to resume its search for insects among the bright, arid cliffs it claims for its own.
I realize that I am seeing more than scenery here. All around me are boundaries—conspicuous where defined by plants, but invisible where respected by animals. No prairie dog has ever traveled across this slope, and no red squirrel has ever scurried into the treeless expanse of the prairie dog town. On no occasion would a rock wren enter the deep pine forest. Should its food supply somehow vanish, it would perish among the bare earth and gully washes of its own habitat rather than hunt the dog town or forest floor.
Each animal species is adapted to the conditions of its preferred environment. The prairie dog and red squirrel have similar roles in their respective habitats, as do the meadowlark in the grassland, the house wren in the deciduous woodlands, the rock wren on barren slopes, and the brilliant western tanager of the pine forests that is calling “pit-ik, pit-ik, pit-ik” from a branch overhead.