The arrival of the female was a strangely drab and undramatic climax to a lifetime of waiting. One second the curlew was feeding busily at the edge of the breakers, surrounded by dozens of plovers, yet alone; the next second the female curlew was there, not three feet away, so close that when she held her wings extended in the moment after landing even the individual feathers were sharply distinguishable. She had come in with a new flock of nine plovers. They had dropped down silently, unnoticed except by the sentinel plover that stood hawk watch while the others fed. She lowered her wings slowly and deliberately, a movement much more graceful than the alighting pattern of the plovers. Her long, downward sweeping bill turned toward him.
The female bobbed up and down jerkily on her long greenish legs and a low, muffled quirking came from deep within her throat. The male bobbed and answered softly.
There was little mental reasoning involved in the process of recognition. It was instantaneous and intuitive. The male knew that he had been mistaken many times before. He knew that the puzzlingly similar Hudsonian curlews were birds of the arctic summer that he had never seen here on the far-south wintering grounds. He knew this new curlew was smaller and slightly browner, like himself, than the others had been. But these thoughts were fleeting, barely formed. It was a combination of voice, posture, the movements of the other bird, and not her appearance, which signaled instantly that the mate had come.
He had never seen a member of his own species before. Probably the female had not either. Both had searched two continents without consciously knowing what to look for. Yet when chance at last threw them together, the instinct of generations past when the Eskimo curlew was one of the Americas′ most abundant birds made the recognition sure and immediate.
For a minute they stood almost motionless, eyeing each other, bobbing occasionally. The male seethed with the sudden release of a mating urge that had waxed and waned without fulfillment for a lifetime. A small sea snail crept through a shallow film of tidewater at his feet and the curlew snapped it up quickly, crushing the shell with his bill. But he didn′t eat it himself. With his neck extended, throat feathers jutting out jaggedly and legs stiff, the male strutted in an awkward sideways movement to the female′s side and handed her the snail with his bill. The female hunched forward, her wings partly extended and quivering vigorously. She took the snail, swallowing it quickly.
In this simple demonstration of courtship feeding, the male had offered himself as a mate and been accepted. The lovemaking had begun. There had been no outward show of excitement, no glad display, simply a snail proffered and accepted, and the mating was sealed.
Now they resumed feeding individually, ignoring each other, but never straying far apart. And the cobble bar by the S twist of the distant tundra river called the male as never before.
At dusk he took wing and circled over the female, whistling to her softly. She sprang into the air beside him and together they flew inland over the coastal hills. They landed on a grassy hillside when darkness fell and they slept close together, their necks almost touching. The male felt as if he had been reborn and was starting another life.
They returned to the beaches at dawn and began to move northward more rapidly, alternating flights of ten miles or so at a time with stops for feeding. The call of the tundra grew more powerful and each day they moved faster than the day before, flying more and eating less. By early February they were a thousand miles north of where they had started, still following the seacoast tideflats, and the annual turgescence of the sex glands with their outpouring of hormones began filling them with a growing excitement. Now the male would frequently stop suddenly while feeding and strut like a game cock before the female with his throat puffed out and tail feathers expanded into a great fan over his back. The female would respond to the lovemaking by crouching, her wings aquiver, and beg for food like a young bird. Then the male would offer her a food tidbit and their bills would touch and the love display suddenly end.
One dusk when the westerly wind was strong off the coastal highlands, they flew inland as they had done every evening, but this time the male led her high above the browning pampas and darkness came and they continued flying. The short daytime flights were not carrying them northward fast enough to appease the growing migratory urge. They left the seacoast far behind and headed inland northwesterly toward the distant peaks of the Andes. Now the male felt a sudden release of the tension within him, for with the first night flight there was recognition that the migration had really begun.
They flew six hours and their wings were tired. It was still dark when they landed, to rest till the dawn. Now they moved little during the day, but at sunset the curlew led his mate high into the air and turned northwestward again. Each night their wings strengthened and in a week they were flying from dusk to dawn without alighting.
They flew close together, the male always leading, the female a foot or two behind and slightly aside riding the air vortex of one of his wingtips. They talked constantly in the darkness, soft lisping notes that rose faintly above the whistle of air past their wings, and the male began to forget that he had ever known the torture of being alone. They encountered numerous plovers but their own companionship was so complete and satisfying that they made no attempt to join and stay with a larger flock. Usually they flew alone.
The northward route through South America was different from the southward flight. When they left the belt of the prevailing westerlies and passed over the pampas into the forested region of northern Argentina, feeding places became more difficult to find. Five hundred miles to the west were the beaches of the Pacific but the towering cordillera of the Andes lay between. From here they could fly northeastward into the endless equatorial jungles of Brazil, where food and even landing places would be scarce for fifteen hundred miles, or they could swing westward to challenge the high, thin, stormy air of the Andes, which had the coastal beaches of the Pacific just beyond. The curlew instinctively turned westward.
For a whole night they flew into foothills that sloped upward interminably, climbing steadily hour after hour until their wings throbbed with the fatigue. And at dawn, when they landed on a thickly grassed plateau, the rolling land ahead still sloped upward endlessly as far as sight could reach, to disappear eventually in a saw-toothed horizon where white clouds and snow peaks merged indistinguishably.
When the sun set, silhouetting the Andean peaks against a golden sky, the curlews flew again. Flight was slow and labored for the angle of climb grew constantly steeper. The air grew thin, providing less support for their wings and less oxygen for their rapidly working lungs. They were birds of the sea level regions and they didn′t possess the huge lungs that made life possible here three miles above the sea for the shaggy-haired llamas and their Indian herders. The curlews tired quickly and hours before dawn they dropped exhausted to a steep rocky slope where a thin covering of moss and lichen clung precariously. For the remainder of the night they stood close together resting, braced against the cold, gusty winds.
Daylight illuminated a harsh barren world, a vertical landscape of grey rock across which wisps of foggy cloud scudded like white wings of the unending wind. And the top of this world was still far above them. The peaks that they yet had to cross were hidden in a dense ceiling of boiling cloud.
Nowhere else in the world outside the Himalayas of India did mountain peaks rear upward so high.
Even here, though, there were insects and the curlews fed. It was slow and difficult feeding, not because food was scanty, but because every movement was a tiring effort, using up oxygen that the blood regained slowly and painfully. At dusk the air cooled suddenly and the fog scud changed to snow. They didn′t fly. The turbulent air currents and the great barrier of rock and glacier ahead demanded daylight for the crossing.
There was no sleep, even little rest, that night. The wind screeched up the mountain face, driving hard particles of snow before it, until at times the birds could hardly stand against it. Then a heavy blast lifted them off their feet and catapulted them twisting and helpless into dark and eerie space. The male fought against it, regained flight control and landed again. But the female was gone.
He called frantically above the whine of the storm, but his calls were flung back unanswered by the wind. When the wind eased, he rose into the air and flew in tight, low circles, searching and calling, in vain. The wind rose, became too strong for flight, and he clung to the moss of the steep rock face and waited breathlessly. When it died momentarily, he flew again, but his endurance waned quickly and he couldn′t go on. He found a hollow where he could be sheltered from the storm and crouched in it, panting with open bill for the oxygen his body craved. When strength returned he flew out into the wild dark night another time, circling, calling, the agony of loneliness torturing him again.
In an hour he found her, crouched in the drifting snow beneath a shelf of shale, as breathless and distraught as he was. They clung together neck to neck and the heat of their bodies melted a small oval in the hard granular snow.
The wind slackened at dawn and the male knew they had to fly, for there could be no lingering here. When the snow changed to fog again and the sun pierced it feebly in a faint yellow glow, they took off and spiraled upward into the flat cloud layer that hid the peaks above. In a minute they were entombed in a ghostly world of white mist that pressed in damp and heavy upon them. They spiraled tightly, climbing straight upward into air so thin that their wings seemed to be beating in a vacuum and their lungs when rilled still strained for breath.
In the cloud layer the air was turbulent. Occasionally there were pockets where the air was hard, and their wings bit into it firmly and they climbed rapidly, then the air would thin out again, and for several minutes they would barely hold their own. Once the light brightened and the curlew knew they were close to the clear air above, but before they could struggle free of the cloud a sudden downdraft caught them, they plunged downward uncontrollably and lost in a few seconds the altitude that had taken many minutes to gain.
They broke free of the swirling cloud mass finally and came out into a calm, clear sky. It was a weird, bizarre world of intense cold and dazzling light that seemed disconnected from all things of earth. The cloud layer just below them stretched from horizon to horizon in a great white rolling plain that looked firm enough to alight upon. The sun glared off it with the brilliance of a mirror. A mile away a mountain peak lifted its cap of perpetual snow through the cloud, its rock-ribbed summit not far above. In the distance were other peaks rising like rocky islands out of a white sea.
The curlews leveled off close to the cloud layer and flew toward the peak. Flight was painful and slow. They flew with bills open, gasping the thin air. Their bodies ached.
As they approached the mountaintop, the wind freshened again. Stinging blasts of snow swirled off the peak into their path of flight. They struggled through and landed for rest on a turret of grey rock swept bare of snow by the wind. Now a new torment racked their aching bodies, for the dry, rarefied air had quickly exhausted body moisture, and their hot throats burned with thirst.
Fifty miles away there were orchids and cacti blooming vividly in the late South American summer, but here on the rooftop of the Americas four miles above the level of the sea was winter that never ended. Not far below their resting place was an eerie zone of billowing white in which it was difficult to distinguish where the snow of the mountainside ended and the clouds began. Yet even here where no living thing could long endure, life had left its mark, for the very rock of the mountain itself was composed largely of the fossilized skeletons of sea animals that had lived millions of years ago, in a lost eon when continents were unborn and even mountain peaks were the ooze of the ocean floors.
The pain drained from their bodies and the curlews flew westward again past the wind-sculptured snow ridges and out into the strangely unattached and empty world of dazzling sunlight and cloud beyond. They flew a long time, afraid to drop down through the cloud again until there was some clue as to what lay below it, and far behind them the peak grew indistinct and fuzzy beneath its halo of mist and snow. The cloud layer over which they flew loosened, its smooth, firm top breaking up into a tumbling series of deep valleys and high white hills. The valleys deepened, then one of them dropped precipitously without a bottom so that it wasn′t a valley but a hole that went completely through the cloud. Through the hole, the birds could see a sandy, desertlike plateau strewn with green cacti clumps and brown ridges of sandstone. It was two to three miles below them, for the Andes′ western face drops steeply to the Pacific.
They had been silent all day, for the high altitude flight took all the energy their bodies could produce, but now the male called excitedly as he led the female sharply downward between the walls of cloud. The narrow hole far below grew larger. The air whistled past them and they zigzagged erratically to check the speed of the descent. At first the air was too thin to give their wings much braking power and they plunged earthward with little control, then the air grew firmer, it pressed hard against their wing feathers and they dropped more slowly. Their ears pained with the change in pressure and when they came out below the cloud layer they leveled off again and headed toward the faint blue line of the Pacific visible at the horizon.
Their brief two or three minutes of descent had brought them with dramatic suddenness into a region greatly different from the cold, brilliant void they had left. They were still so high that features below were indistinct, but they were nevertheless a definite part of the earth again. Now there was land and rock and vegetation below them, not an ethereal nothingness of cloud. Here the day was dull and sunless, not glaring with light, but the air was warm. And the air now had a substance that could be felt. It gave power and lift to their wings again and it filled their lungs without leaving an aching breathless torment when exhaled.
They flew swiftly now, for the land sloped steeply and their plane of flight followed the contour of the land downward. Late that afternoon they alighted on a narrow beach of the Pacific. They drank hurriedly of the salt water for a couple of minutes. Then they fed steadily until the dusk.
With twilight the sky cleared and the great volcanic cones of the Andes, now etched sharply against the greying east, assumed a frightening massiveness. Every year the male curlew′s migratory instinct had led him across this towering barrier of limestone, storm and snow. And every year before the memory of it dimmed, the curlew looked back and even his slow-working brain could marvel at the endurance of his own wings.