Читать книгу Magdalena Mountain - Robert Michael Pyle - Страница 16

Snow tries to accumulate on the stony face of Magdalena Mountain, but Boreas scrapes it away with his rasping breath. As the storms grow in force and frequency into December, even the gale itself cannot remove its own white detritus. Then the peak changes color like the ptarmigan secreted on its slopes, from the gray-brown pelage of November to the pure white snow cone of January.

Marmots sleep their deep sleep that will last the mountain lion’s share of a year, while pumas prowl hungry across the frozen hems of the boulder fields and retreat, finally, to the forests below. The pikas slumber less—and less deeply—than the marmots. They awaken later than their brief summer somnolence allowed, but awaken just the same each day to preen their lice away and to munch on the fragrant hay they’ve so busily laid by. Toward spring, both the sacked-out rock chucks and the catnapping conies will give birth and suckle their young in the crannies made cozy by their own body heat.

Now the ptarmigan and the varying hares make only tracks and shadows, not patches of brown, on the pallid winterscape. They forsake the wind-ravaged fellfields for the relative shelter of the forest fringe, twisted and clumped subalpine fir and Engelmann spruce almost bare on top but thick-skirted below the trimline of the wind. The ptarmigan especially haunt the edges of the willow swales, feeding on their tight-packed buds. These snow ghosts are followed by hopeful coyotes, still brown and leaner than ever.

No one comes to Magdalena Mountain in the winter except a few foolhardy climbers and the helicopters sometimes sent to pluck them off. Cross-country skiers remain far below, and jets swerve north to avoid this conical object in their takeoff path as they gain altitude on their way from Denver to Salt Lake, Boise, Portland, or Seattle. Any climber reaching the summit has to clamber across hundreds of boulders, ice-rimed, slick, or cracking under winter’s weight. Frost probes every cleft, then swells and splits the stones asunder. But no climber, sure to be quick or be dead, would hang around to watch the prying frost do its work, nor to listen for the slow heartbeat of marmot or the faster pulse of pika in the rockpile below.

With the summer sounds gone, the piping of the marmot stilled, the sentry-squeak of the pika silenced, Magdalena Mountain seems all but lifeless on the surface. But beneath the snow and the stones, life carries on, if not exactly teeming. Among the few creatures as happy now as ever are the grylloblattids. Wingless, primitive relatives of crickets, more resembling roaches, these ice crawlers (as they are called) cherish the cold and die if they become too warm. Glaciers, snowfields, and rockslides are their natural homes. In the dead of winter, a grylloblattid prowls the talus slope in search of any animal food it can find. With its slender antennae it probes here and there as its six legs carry it speedily over cold stone, solid ice, and rotting vegetation. A pale amber predator, the ice crawler works the frozen, uncrowded territory in its search for winter food.

Among the candidates are the winter-passage stages of arctic-alpine butterflies: eggs, caterpillars, and chrysalides, proof against the wind, carrying their fragile selves through hostilities so severe as to be found only in such high ranges of rock as these. For Erebia, winter is a time of passive repose, to be gotten through alive. Antifreeze in the tiny larva’s blood keeps ice crystals from rupturing delicate tissues. His metabolism has dropped to near nil. Winter for the Magdalena alpine is a time when nothing happens at all other than bare, tenuous existence. This terrible season claims few lives among his brood. The flash freeze keeps most predators at bay while cold-storing the frost-free larvae for spring. Erebia, curled and still, guards a flicker of life inside his sliver of self, and that is all he has to do. Chances are, no one is going to interfere.

But the grylloblattid creeps into the hollow where Erebia and several of his siblings have gone to ground. It palps a beetle grub and consumes it in minutes before moving on to an egg mass of a rock spider, which it nibbles like popcorn. Two Magdalena larvettes, minor morsels that they are, fall prey to the grylloblattid before it swerves out of this particular declivity and moves on to a pika’s den, looking for lice, and is fulfilled. This is winter’s last close call for Erebia. He’ll ride out the rest, secure in his alpine tent of silk and grass.

There comes a break in the weather. A hint of a promise of an imputation of the rumor of spring arrives on a warm Chinook wind. Grasses in the foothills show the first fleeting green, and along the streams, cottonwood buds swell toward bursting in balsamic waves of fragrance. Up on the mountain, a thaw too soon might start the growing season perilously early, and an unusually late blizzard could jeopardize the early birds.

But it isn’t only temperature rising, or a warm wind. Too well honed by evolution to the irregular weather of the Rockies to be fooled, Erebia waits for the right combination of warmth and length of day before stirring. The alpine grasses he’ll need are tuned to the same two signals. Both the intensity and the duration of the sun must agree before the key is turned.

Such conditions befall the face of Magdalena Mountain one day in late April. The sun strikes the easternmost of the mountain’s twin summits twelve and a half hours before it sets behind the western peak. The temperature hits fifty-five Fahrenheit in the sunshine at noon. A pika pokes its gray face up into the sunshine, and a marmot rolls over in its dreams of green grass and glacier lilies.

Green creeps up a grass shoot cell by cell, and with it, a very small caterpillar. The worm turns, and Erebia begins to feed.