In more isolated parts of the country, a few chimney swifts cling to old-fashioned ideas: they still nest in hollow trees. The western cousin of the chimney swift – Vaux’s swift – only of recent years has begun to make the transition from trees to chimneys. So broadminded and so adaptable is the true chimney swift, however, that it has made the most of various other conveniences of civilization, nesting in abandoned buildings, in wells and cisterns, and in silos.
For its intra-chimney architecture the swift is equipped with enormously developed salivary glands. These secrete a thick, gluey saliva useful in fastening twigs together and in cementing the hammocklike nest to the wall of the chimney. The Chinese swift dispenses with twigs, fashions its entire nest of saliva, and so creates the principal ingredient of the delicacy known as bird’s nest soup.
During the nesting season the salivary glands enlarge, providing copious supplies of the needed cement. Later they shrink, but the hollow spaces left in the cheeks of the swift are put to good use – the bird crams them full of insects to bring back to its hungry babies.
Nest building takes two to three weeks, even longer if the days are rainy and the glue melts. Every twig used is collected by an amazing method: the bird snatches them on the wing from trees and shrubbery. To this day ornithologists cannot agree whether it uses feet or beak in the process.
Swifts are devoted parents. The male and female take turns incubating the eggs during the nearly three weeks required for the young to hatch. Thereafter, both birds assume the chore of keeping the infant mouths filled with insects, a task that must be performed faithfully for about four weeks before the young swifts are able to take to the sky in their own behalf.
Unexplained as yet is the fact that observers have sometimes seen three adult birds tending a nest. The polite but wholly tentative theory is that the parents have engaged a “nursemaid.” More realistic persons scoff at that and say the swift is polygamous. What the truth is, no one actually knows.
The chimney swift is rated the fastest small bird in North America and has few natural enemies it needs to fear. Flight records for an Asiatic swift indicate speeds up to 200 miles an hour. It is debatable whether even a duck hawk can overtake one in straight-away flight. An occasional swift, however, may be snatched by a hawk as the birds are circling above a chimney, preparatory to entering for the night.
From one enemy – rain – the bird has no defense. Cold rains, long continued, wash the skies clear of insects. Deprived of food, the swifts weaken and die in great numbers. During one unseasonably wet June reports of dead swifts came from all over southern New England, wheelbarrow loads were taken from the chimneys of large mills, bushels from the base of a chimney at Clark University. Fortunately, such occurrences are comparatively rare.
The life story of the chimney swift has been pieced together by naturalists and amateur birders only with the greatest patience and perseverance. A bird who never perches on a tree where you can focus your binoculars on him, who never visits feeding stations, who spends almost all the daylight hours far above your head, and who, in the fall, vanishes so suddenly and completely that only within the past year has his winter home been discovered – such a bird is not an easy subject for his would-be biographers.
Perhaps because of the very difficulty of the job, an extraordinary number of people seem to have interested themselves in the chimney swift, and have gone to endless trouble to learn its habits. One woman in Iowa had an imitation chimney, equipped with observation tower, built in her back yard so she could study the home life of the swifts that later nested in it. A West Virginia farmer suspended tin coffee cans in his chimney as an invitation to the swifts to nest there. The birds accepted, later permitted the farmer to raise the cans to the top of the chimney at intervals to photograph the young. The ornithologist and artist George Mitsch Sutton, as a young man in West Virginia, repeatedly climbed a tall church chimney and hung for hours, cramped, shivering, and wretched, just below the mouth of the chimney so he could make accurate notes on the wing movements of the swifts as they dropped into the chimney. And all over eastern United States and Canada, people have industriously banded chimney swifts in an effort to trace their migrations, until the total of swifts marked with identifying metal bands now exceeds 375,000.
Banding 375,000 chimney swifts is not as simple as it may seem. If you are one who insists upon lying abed in the chilly dawn or whose experience as a steeple jack is limited, don’t take up swift banding as a hobby. It requires a certain Spartan fortitude. Unlike most birds, the insect-eating swifts cannot be attracted to cage traps baited with grain or other foods. They have to be caught as they emerge at daybreak from the large chimneys where thousands of them sleep, especially near the time of the fall migration.
Swift banders stand about on roofs, shivering as they wait for daylight and the birds. They risk their necks clambering to the tops of tall chimneys to set their traps. They incur the suspicion of the law as they skulk about empty buildings in the small hours. Despite these hazards, Constance and E. A. Everett of Minnesota once wrote cheerfully to an ornithological journal about “the fun of banding chimney swifts.”
A few months ago the banders had their reward. Although many marked swifts had been recaptured, all recoveries had been made within the known summer range of the bird, and the winter home of the swift was still undiscovered. Then to the U.S. headquarters for the study of bird migration, the Fish and Wildlife Service, came a long, official envelope from the American Embassy at Lima, Peru. It contained thirteen bands, taken from chimney swifts shot by Indians in the jungles of Peru during the northern winter. Records showed that the birds had been banded in Tennessee, Illinois, Connecticut, Alabama, Georgia, and Ontario, dates of banding ranging from 1936 to 1940.
For the thirteen small birds, death won ornithological fame. The swift was the last North American bird whose winter range was unknown. The thirteen had now provided the solution of a major mystery of bird migration, had filled in the missing paragraphs in the biography of their race.
5
[1945]
Road of the Hawks
RACHEL CARSON’S LIFELONG FASCINATION with the sea was matched by an equally intense interest in birds, nurtured first in the company of her mother in the hills of western Pennsylvania. It was a passion she maintained throughout her life.
At her U.S. Fish and Wildlife job in wartime Washington, Carson’s ornithological interests found outlet in company with other members of the newly organized Audubon Society of the District of Columbia. Carson was soon elected to the Society’s Board of Directors where she worked with artist Roger Tory Peterson and other notable scientists. Society activities also provided the rare occasion for social gatherings and outings that Carson enjoyed.
One of the most popular Society trips was to the Hawk Mountain Sanctuary in eastern Pennsylvania to watch the fall migration. In October, 1945, Carson, along with her Fish and Wildlife colleague and friend Shirley Briggs, who was an equally avid amateur ornithologist, spent two days at Hawk Mountain. Perched on a rocky promontory, braving a bone-chilling wind, Carson watched the hawks and took notes on their behavior. The following fragment from those field notes reveals how deeply Carson was affected by the spectacle of the hawks, but also shows how she related even non-marine experiences in nature to the ocean and to the ancient history of the earth.
THEY CAME BY like brown leaves drifting on the wind. Sometimes a lone bird rode the air currents; sometimes several at a time, sweeping upward until they were only specks against the clouds or dropping down again toward the valley floor below us; sometimes a great burst of them milling and tossing, like the flurry of leaves when a sudden gust of wind shakes loose a new batch from the forest trees. [ … ] On the horizon to the north, formed by a series of seven peaks running almost at right angles to the ridge on which we sit, an indistinct blur takes form against the sky. Second by second the outlines sharpen. Soon the unmistakable silhouette of a hawk is etched on the gray. It is too s
oon to make out the identifying lines of wing and tail that mark him for one species or another. On he comes, following the left side of the ridge, high up. Sometimes he banks steeply and his outlines melt into the sky. Then a swift wing beat or two and we have him in our glasses again [ … ]
Now follows a long wait with no more hawks. I settle back against the rock behind me, seeking shelter from the wind, trying vainly to draw some physical comfort from the hard angularity of stone. The cold is bitter. The morning had seemed reasonably mild down in the valley, as we had our quick cups of coffee in the predawn blackness. But here on the mountain top we are in the sweep of all the winds out of a great emptiness of sky, and the cold seeps through to the very marrow of my bones. But cold, windy weather is hawk weather, and so I am glad, although I shiver and my nose reddens, and I look speculatively at my thermos of hot coffee. But that must last the day, and now it is only ten o’clock.
Mists are drifting over the valley. A grayness overhangs all the sky and the clouds seem heavy with unshed rain. It is an elemental landscape – a great rockpile atop a mountain, nearby a few trees that have been stripped and twisted by the mountain winds, a vast, pale, arching sky.
Perhaps it is not strange that I, who greatly love the sea, should find much in the mountains to remind me of it. I cannot watch the headlong descent of the hill streams without remembering that, though their journey be long, its end is in the sea. And always in these Appalachian highlands there are reminders of those ancient seas that more than once lay over all this land. Halfway up the steep path to the lookout is a cliff formed of sandstone; long ago it was laid down under shallow marine waters where strange and unfamiliar fishes swam; then the seas receded, the mountains were uplifted, and now wind and rain are crumbling the cliff away to the sandy particles that first composed it. And these whitened limestone rocks on which I am sitting – these, too, were formed under that Paleozoic ocean, of the myriad tiny skeletons of creatures that drifted in its water. Now I lie back with half closed eyes and try to realize that I am at the bottom of another ocean – an ocean of air on which the hawks are sailing.
6
[1946]
An Island I Remember
IN THE DECADE following the publication of Under the Sea-Wind in 1941, Carson worked on an extended profile of the ocean which would become The Sea Around Us. In 1946, after almost ten years in the federal government, Carson had accumulated enough annual leave for a month’s vacation in Boothbay Harbor, Maine, the site of a Bureau of Fisheries laboratory engaged in research on lobster reproduction, and a coastal area she had longed to visit.
Carson along with her mother and her two cats rented a tiny, secluded pink cottage on the shore of the Sheepscot River west of town. It looked out to Indiantown Island, a mysterious, spruce-covered strip of lush forest where the wind rustled through the trees and at sunset a hermit thrush sang its eerie song.
Carson fell in love with the beauty of Maine that summer and determined that one day she would have a place of her own there. She told her friend Shirley Briggs in a letter, “the only reason I will ever come back [to Maryland] is that I don’t have the brains enough to figure out a way to stay here the rest of my life.” Seven years later the success of The Sea Around Us enabled her to buy land and build a cottage along the Sheepscot on Southport Island.
Among the unpublished fragments in Carson’s papers, there is no more arresting example of Carson’s ability to absorb her surroundings with all her senses, or of her pleasure in the diverse fabric of the natural world.
IT WAS ONLY A SMALL ISLAND, perhaps a mile long and half as wide. The face it presented to the mainland shore was a dark wall of coniferous forest rising in solid, impenetrable blackness to where the tops of the spruces feathered out into a serrate line against the sky. There was no break in that wall anywhere that I could see, no suggestion of paths worn through island forests, no invitation to enter. At high tide the sea came up almost to the trees, with only little patches of light colored rock showing at the water line, like white daubs made by a painter’s brush. As the tide ebbed and the water dropped lower on the rocks, the white patches grew and merged with each other, exposing the solid granite foundations of the island, so that now there was a high rocky rampart, on which grew the living green wall of the forest.
There was perhaps a quarter of a mile of water between the island and the mainland shore where our cabin stood, its screened porch at the sea wall and its back against a steep hillside where ferns were dark among the rocks and the branches of great hemlocks reached down to touch the ground. Day after day the island lay under the summer sun, with no sound coming from it, and nothing moving at the visible edges of the forest. On every low tide I could see a solemn line of cormorants standing on a rocky ledge that ran out from the south end of the island, their long necks extended skyward. The gulls were less broodingly protective of the approaches to the island forest, their presence about the shores of the island more casual as they perched on the weed-covered rocks while waiting for the turn of the tide.
About sundown the island, that had lain so silent all day long, began to come to life. Then the forms of large, dark birds could be seen moving among its trees, and hoarse cries that brought to mind thoughts of ancient, reptilian monsters came across the water. Sometimes one of the birds would emerge from the shadows and fly across to our shore, then revealing itself as a great blue heron out for an evening’s fishing.
It was during those early evening hours that the sense of mystery that invested the island drew somehow closer about it, so that I wished even more to know what lay beyond the wall of dark spruces. Was there somewhere within it an open glade that held the sunlight? Or was there only solid forest from shore to shore? Perhaps it was all forest, for the island voice that came to us most clearly and beautifully each evening was the voice of a forest spirit, the hermit thrush. At the hour of the evening’s beginning its broken, silvery cadences drifted with infinite deliberation across the water. Its phrases were filled with a beauty and a meaning that were not wholly of the present, as though the thrush were singing of other sunsets, extending far back beyond his personal memory, through eons of time when his forebears had known this place, and from spruce trees long since returned to earth had sung the beauty of the evening.
It was in the evenings, too, that I came to know the herring gulls as I had never known them before. The harbor gull – the gull of the fish wharves – is an opportunist. He sits with his fellows on the roofs above the harbor, or each on his wharf piling, and waits, knowing at what hour the refuse will be discharged from the fish house, or when the first of the returning fishing boats will appear on the horizon, to be met with excited cries. But the gulls of the island were different. They were fishermen, and like the men who handle the nets, they lived by their own toil.
I suppose a certain amount of regular fishing went on during the day, but I was especially aware of the excitement that attended the runs of young herring that came into our cove each evening.
It is strange to reflect on that twilight migration of the young herring that by day have moved widely through the coastal waters, but now are drawn, as the water darkens to black and silver, to follow the channels between the rocky foundations of the islands.
We would know the herring were coming by watching the behavior of the gulls. Most of the late afternoon they would have dozed on their rocky perches along the shore of the island. But as sunset neared and the shadows of the spruces began to build dark spires in the water, a stir of excitement would pass among the gulls. There would be a good deal of flying up and down the channel, as though scouts were coming and going. It seemed that some intelligence of the movements of the fish was being spread among the birds. More and more of the gulls would join in the scouting parties, until the whole flock was in movement, their sharp, staccato cries coming across the water.
When the water was glassy calm, holding the colors of the evening sky on its surface, we could time as exactly as the gulls the
arrival of the herring in our cove. Suddenly the silken sheet would be dimpled by a thousand little noses pushing against the water film. It would be streaked by a thousand little ripples moving eagerly toward the shore. It would be shot through by a thousand silver needles as the fish, swimming just beneath the surface, disturbed the placid sheet. Then the herring would begin flipping into the air. It seemed it was always out of the corner of your eye that you saw them, and you never quite knew where to look for the next little herring skipping recklessly into the air in a sort of back somersault. They did it as though it were great fun – this rash defying of a strange and hostile element, the air. I believe it was a sort of play indulged in by these young children of the herring. They looked like silvery coins skipped along the surface. I never actually saw any of the youngsters caught in the air by a gull, but the quick eyes of the birds must certainly have been attracted by the bright flashes.
The gulls would greet the arrival of the herring schools with a frenzy of excitement, swooping, plunging, crying loudly. A gull does not dive as a tern does; he swoops and, not quite alighting, plucks his fish from the water. It takes a good eye and good timing. It is less graceful than the beautiful, clean dive of a tern, but perhaps it requires equal skill.
A night I especially remember there had been a large run of herring into the cove and it had come somewhat later than usual. The gulls, apparently determined to make their catch despite the gathering darkness, fished on until it was hard to understand how they could possibly see the fish. We could see their moving forms against the island – white, mothlike figures against the dark backdrop of the island forest, fluttering to and fro and all the while uttering their cries, in a scene out of some weird shadow world.