CHAPTER ONE
FLOOD TIDE
The Island lay in shadows only a little deeper than those that were swiftly stealing across the sound from the east. On its western shore the wet sand of the narrow beach caught the same reflection of palely gleaming sky that laid a bright path across the water from island beach to horizon. Both water and sand were the color of steel overlaid with the sheen of silver, so that it was hard to say where water ended and land began.
Although it was a small island, so small that a gull might have flown across it with a score of wing beats, night had already come to its northern and eastern end. Here the marsh grasses waded boldly out into dark water, and shadows lay thick among the low-growing cedars and yaupons.
With the dusk a strange bird came to the island from its nesting grounds on the outer banks. Its wings were pure black, and from tip to tip their spread was more than the length of a man's arm. It flew steadily and without haste across the sound, its progress as measured and as meaningful as that of the shadows which little by little were dulling the bright water path. The bird was called Rynchops, the black skimmer.
As he neared the shore of the island the skimmer drifted closer to the water, bringing his dark form into strong silhouette against the gray sheet, like the shadow of a great bird that passed unseen above. Yet so quietly did he approach that the sound of his wings, if sound there were, was lost in the whisper song of the water turning over the shells on the wet sand.
At the last spring tide, when the thin shell of the new moon brought the water lapping among the sea oats that fringed the dunes of the banks, Rynchops and his kin had arrived on the outer barrier strip of sand between sound and sea. They had journeyed northward from the coast of Yucatan, where they had wintered. Under the warm June sun they would lay their eggs and hatch their buff-colored chicks on the sandy islands of the sound and on the outer beaches. But at first they were weary after the long flight and they rested by day on sand bars when the tide was out or roamed over the sound and its bordering marshes by night.
Before the moon had come to the full, Rynchops had remembered the island. It lay across a quiet sound from which the banks shouldered away the South Atlantic rollers. To the north the island was separated from the mainland by a deep gutter where the ebbing tides raced strongly. On the south side the beach sloped gently, so that at slack water the fishermen could wade out half a mile before the water came above their armpits as they raked scallops or hauled their long seines. In these shallows young fishes swarmed, feeding on the small game of the waters, and shrimp swam with backward flipping of their tails. The rich life of the shallows brought the skimmers nightly from their nesting grounds on the banks, to take their food from the water as they moved with winnowing flight above it.
About sunset the tide had been out. Now it was rising, covering the afternoon resting places of the skimmers, moving through the inlet, and flowing up into the marshes. Through most of the night the skimmers would feed, gliding on slender wings above the water in search of the small fishes that had moved in with the tide to the shelter of grassy shallows. Because they fed on the rising tide, the skimmers were called flood gulls.
On the south beach of the island, where water no deeper than a man's hand ran over the gently ribbed bottom, Rynchops began to wheel and quarter over the shallows. He flew with a curious, lilting motion, lifting his wings high after the downstroke. His head was bent sharply so that the long lower bill, shaped like a scissor blade, might cut the water.
The blade or cutwater plowed a miniature furrow over the placid sheet of the sound, setting up wavelets of its own and sending vibrations thudding down through the water to rebound from the sandy bottom. The wave messages were received by the blennies and killifish that were roving the shallows on the alert for food. In the fish world many things are told by sound waves. Sometimes the vibrations tell of food animals like small shrimps or oar-footed crustaceans moving in swarms overhead. And so at the passing of the skimmer the small fishes came nosing at the surface, curious and hungry. Rynchops, wheeling about, returned along the way he had come and snapped up three of the fishes by the rapid opening and closing of his short upper bill.
"Ah-h-h-h," called the black skimmer. "Ha-a-a-a! Ha-a-a-a! Ha-a-a-a!" His voice was harsh and barking. It carried far across the water, and from the marshes there came back, like echoes, the answering cries of other skimmers.
While the water was reclaiming inch after inch of sandy shore, Rynchops moved back and forth over the south beach of the island, luring the fishes to rise along his path and seizing them on his return. After he had taken enough minnows to appease his hunger he wheeled up from the water with half a dozen flapping wing beats and circled the island. As he soared above the marshy eastern end, schools of killifish moved beneath him through the forests of sea hay, but they were safe from the skimmer, whose wingspread was too great to allow him to fly among the clumps of grass.
Rynchops swerved out around the dock that had been built by the fisherman who lived on the island, crossed the gutter, and swept far over the salt marshes, taking joy in flight and soaring motion. There he joined a flock of other skimmers and together they moved over the marshes in long lines and columns, sometimes appearing as dark shadows on the night sky; sometimes as spectral birds when, wheeling swallow-like in air, they showed white breasts and gleaming underparts. As they flew they raised their voices in the weird night chorus of the skimmers, a strange medley of notes high-pitched and low, now soft as the cooing of a mourning dove, and again harsh as the cawing of a crow; the whole chorus rising and falling, swelling and throbbing, dying away in the still air like the far-off baying of a pack of hounds.
The flood gulls circled the island and crossed and recrossed the flats to the southward. All through the hours of the rising tide, they would hunt in flocks over the quiet waters of the sound. The skimmers loved nights of darkness, and tonight thick clouds lay between the water and the moon's light. | 
