They met low over the ground with a clash of wings, then climbed several feet as if going up an invisible pole. When the spat was over Eremophila flew toward his song post. His neighbor followed in pursuit. Now the neighbor was in trespass. Eremophila turned and drove him back to the border. Back and forth they flew, moving eastward as they chased, until, in fury, they flew into a third lark’s land. Now three of them fought for their boundaries. Other larks in the field listened to the battle and excitedly voiced their stay-clear signals. When the combatants swung north, the lark of the northern territory joined the fray. The fighting was now well away from Eremophila’s territory, and he sped back to his song post. Here he burst into his creaking melody, preened his feathers, and glanced up to see the combatants coming toward him again. He warned them with “chee-zit” and plunged after them. They sped away, and Eremophila circled back along his boundary.
A few minutes later the battle stopped and all the larks returned to their territories. Some had lost feathers, some were panting, but none of the precious boundaries had changed in the minds of the birds. Through these fights, neighbors came to agree on property.
A flock of male red-winged blackbirds swooped into Eremophila’s territory. The lark did not bother them, for they were not his kind. The blackbirds were a hustling group, running and jumping, flying and hopping as they sought food among the new shoots of grass that were at last coloring the brown winter fields.
Five male brown-headed cowbirds coasted into the feeding flock of blackbirds, and there ended their long migration from the south. They fitted perfectly into the flock of their coal-black relatives, for the cowbirds were also a glistening black. However, they were different; their heads were a walnut brown, and they did not have the splash of red and orange on their shoulders that the red-winged blackbirds wore. Like the red-winged blackbirds, the cowbirds were awaiting the arrival of their mates.
They moved in this noisy fraternity until the drab brown female cowbirds arrived on a warm south wind during the last week of March. The cowbirds left the blackbirds to join their mates in the trees that bordered the fields. Filled with the festivities of the season, they danced and courted.
Their performances opened with a formal bow, like a stately minuet, then their enthusiasm seemed to run away with them, and they all but somersaulted from the tree limbs as they dipped too low. As they toppled, their wings twisted out and they whistled their cracking love song. The dance seemed badly performed, and the singing just as poor, but the females found it to be impressive.
Over and over Molothrus, the male, bowed and toppled and sang as he moved toward Ater, the female. She responded by flying out across the fields to the pasture fence. Molothrus followed her. Two other males came to the fence where she perched, but Molothrus stood between them and Ater. This was to be his mate. He repeated over and over again the curious dance of the cowbird.
Two fence posts away, Melospiza, the song sparrow, chipped his dislike for the cowbirds. Melospiza had been on the farm for a week. He had returned to this little patch of land along the fence where he had lived the year before. It was a moist spot that could not be worked by the heavy farm machinery, and had grown up in dogwood, elderberry, and milkweeds. He was busy defending it against the young male song sparrows who were arriving from the south looking for home sites. He heard a neighboring male sing from another territory. He flew toward him, then burst into the measures of his melodious song.
Ater, the female cowbird, listened attentively. Perhaps the birds were nesting. She saw they were still setting up their territories and flew to a herd of cows in the pasture. She ran in and out of the legs of the animals looking for insects they might stir up. From this habit of following the cattle, the cowbird got its name. Before the white man brought his cows to America, the cowbird probably followed the bison.
The grasses were green around the nest of Eremophila, the horned lark, and new shoots were hiding the open structure. Two days ago the eggs had hatched and the first nestlings of the field had raised their heads for food. Eremophila and his mate answered their cries, and before the day was over the nestlings had doubled their weight. The little birds had begun their desperate race to fledge before misfortune befell them. On the second evening of their life the race was over. They had lost.
It was the presence of the great owl, Bubo, that ended this struggle. Felis, the house cat, had been so badly frightened by the owl that he changed his hunting habits. He had kept to the fields near the barn.
As cautious as the horned larks had been about their secret, their frequent trips to the nest had been seen by the cat. He had come to the field the second day after the hatching and was crouched beneath a plow that had been left in the field. Felis was always hungry. No one ever fed him. He lived on his own. He saw the female come into the nest and settle down over the young to brood them. He slunk from his hiding place and crept forward. His eyes were riveted on the spot where the lark had settled. He could not see her, but he knew she was there. Slowly he inched toward her, his belly silently brushing the grasses. Never did he shift his gaze. His muscles tensed as he closed, ready for the final spring. But there was nothing to see or hear. He waited, his nose tasting the air for scent of his prey. Only ten feet away the lark sat tight on her nest. She heard the warning note of Eremophila. Eremophila had flown in with food, and with characteristic vigilance had scanned the field before going to the nest. He saw the cat. He called to his mate, then hovered over Felis. The cat glanced up at him and betrayed his position to the brooding female. The cat waited a moment longer and then arose and gave up the chase. However, he continued forward, walking slowly through the field. He was startled as the female burst from the nest, almost beneath him. The female flew only a few feet and then ran through the grasses with raised wings, but Felis did not follow. The nestlings were raising their heads beneath him.
Spring climaxed during April. With each warm wind from the south a new wave of migrating birds would come to the fields or forest. The vesper sparrows and savannah sparrows flew up from the warm south and joined the horned larks in the fields. The first of the wood warblers arrived, the myrtle warbler. They stayed only a few weeks in the big maple forest before they flew on to nest in their spruce forests of the north.
The wild flowers pushed up above last year’s fall of leaves. The skunk cabbages unfolded in the wet bottom lands, and the spring beauties and hepatica bloomed on the hills. As the flowers of the maple trees opened to the sun, below them, the dog tooth violets threw back their yellow petals. The sun, wind, temperature, and moisture awakened the life of the land, and the spring that Bubo and Black Talon had months before foretold was upon the earth.
Parus, the titmouse, started nesting. Bicolor, his mate, found a cavity in a young maple not far from the sugarhouse. She busily cleaned the cavity, carrying out bits of dead wood in her bill. It seemed an endless task, but she finally dug it deep enough to hold her young and lined it with dry grasses and bark fibers.
There were no other titmice on Parus’s territory now. The winter troop had broken up and flown away when Parus had courted Bicolor. Sitta, however, remained, for there was no competition between the titmouse and the nuthatch. Sitta’s mate had selected a nest site in the dead branch of a beech tree. As in winter, the titmouse entered from above, the nuthatch from below.
Other birds of the woodland began their nests. Richmondena, the cardinal, watched his mate, Cardinalis, build their nest in the grapevine thicket. The vine was so dense that it bowed the sapling that supported it. In the midst of it she built a flimsy nest of sticks which appeared to be part of the tangle.
Although the birds of the field and forest were singing and nesting and working with great cheer, they all lived in cold fear, knowing that the great horned owls shadowed their lives. Occasionally they would hear the crows ganging Bubo or Black Talon, and they would go about their duties with nervous movements.
Another enemy was watching Cardinalis as she worked. Ater, the femal
e cowbird, was perched in a tree above the grapevine tangle. She waited until Cardinalis flew up the fence row to hunt with Richmondena, then she slipped into the grapevine and stood on the edge of the incomplete nest.
A moment later she left as silently as she had come. At the edge of the woods she perched on a hawthorn limb. Her eyes were on a female song sparrow who was carrying nesting material to a patch of dense grasses. She watched the sparrow make three trips to the site. Her mate called her and she flew off to join him. Then Ater flew to the patch of grass and poked her head under an arch in the tussock. Ater had found the beginnings of another nest.
She departed and flew across the field to the pasture fence where Melodia, mate of Melospiza, the song sparrow, was also making her nest. Melodia was under the dogwood bush selecting the fine sedges with which to line her nest. She looked up to see Ater perch herself on the fence post.
Melodia recognized Ater as a menace. Here was a social parasite. Melodia knew that Ater had laid two eggs in one of her nests last year. She stopped her building to fly to the fence and chip at the cowbird. She still carried the collection of sedges in her bill, telltale evidence of her work. This was all Ater wanted to know. She had found Melodia’s nest yesterday, and had just come by to see if she were still working on it.
At this moment Melothrus, the male cowbird, flew in and joined Ater. He bowed and squeaked to her. Ater knew that all was in readiness for her and she returned the attentions of Melothrus.
The next day Ater checked the cardinal nest, the nests of the two song sparrows, and other hidden bird homes that she had found. Only the birds of the tree cavities, Parus and Sitta, were safe from her intents.
On the forenoon of the last Tuesday in April, Ater checked the song sparrow nest in the swamp. Melodia had laid two eggs in it. Ater stood at the nest for several seconds, then jabbed her beak into one of the eggs and flew off with it. In the green grasses of the pasture she ate it. Then she went off to feed with a small group of cowbirds that were following the cattle.
Early the next morning, a half hour before sunrise, Ater returned to the song sparrow nest. When she departed from it a few seconds later, there were again two eggs in the nest. One was slightly larger and more heavily spotted. It was the cowbird egg that Ater had just laid. So well was she fitted to this way of nesting that it took her only a small part of a minute to do her reproductive task for the day. Ater would never know the feel of a warm clutch of eggs against her body. She would never know the excitement of fledging time, nor the trials of a parent caring for reckless little fledglings. For Ater these things were lost in the dark days of history, when tens of thousands of years ago one of her ancestors, probably by chance, laid the first cowbird egg in another bird’s nest. The scheme worked, and gradually the cowbird ceased to nest and depended entirely upon other birds to incubate and hatch its eggs and to raise its young.
Later that morning Melodia returned to her nest. She sat on it an hour and when she left there were three eggs, two of hers and one of Ater’s. On the next morning, Thursday, when Melodia returned, there were still three eggs, but only one of them was hers, the other two were Ater’s. Melodia laid the fourth egg in the nest, and then she did something different. She returned to the nest about three hours after she had laid, straightened a grass at the edge, and slipped down upon the cold eggs. Slowly they warmed as the heat of her body seeped into them, and life within the eggs developed. Gradually during the day Melodia fell into the relentless schedule of incubation. She left the nest to eat and exercise. Each time she came back, she stayed a little longer than before, until by the end of the day she was spending about half of her time on the nest. She slept on the nest that night.
Friday morning Melodia laid her fifth and final egg and her incubation rhythm became regular. Ater did not come to Melodia’s nest that morning. Instead, she slipped through the grapevine tangle to lay her third egg in the cardinal nest. Saturday and Sunday morning she laid in the song sparrow nest by the hawthorn bush. Monday morning she laid in the nest of the towhee. Tuesday she was making her way to the cardinal nest again, when she happened to see Black Talon preening close against the bole of an old basswood. She was so terrified that she fluttered to the ground and ran under a tussock of grass. Here she dropped her egg on the cold ground.
This was the last of her first round of eggs. It was the second day of May and spring was full in the forest and fields. She rested a week before she began her second round.
The mourning dove nest in the basswood tree was empty. The timothy stalks were dangling over the limb of the tree and the apple sticks had fallen onto the ground, for the young had fledged two weeks ago. They were sitting with their parents on the telephone wires along the road, a half a mile south of the forest. It had been a desperate period of incubation and nestling raising for the female mourning dove. Bubo had come to the clearing almost every night to hunt. Each night she feared death. By the time the young had fledged, the dove was thin and tired. When they could fly she took them away from the forest to the trees along the road.
In the hayfield, Eremophila, the horned lark, was excited. The young of his second nesting were just out of the nest. One bright-eyed fledgling was perched on a slender alfalfa stem, fluttering his wings and opening his mouth for food. He had hopped out of the nest that morning when Eremophila had come toward him with a worm. This little drab brown bird, whose flight feathers were still enclosed in their sheaths, started a fluttering exodus from the nest under the brown grass. He was followed by the three other nestlings, and the corner of the hayfield was noisy with their calls.
Eremophila and his mate chipped and called. Their excitement was felt by a neighboring pair of vesper sparrows, who had not yet laid their eggs. The sparrows flew around their territory chipping. The savannah sparrows in the corner of the field joined the excitement. The female flew to a fence post still carrying material for the nest she was building. Chirping up from the grass came a grasshopper sparrow. He sat on the wire of the fence and chipped, too. He was still busy setting up a territory. All heralded the fledging of the young horned larks—the first young of the fields.
Deep in the woods the crows called as they ganged Bubo. The birds became quiet as they were reminded of the fearful owl that dominated their lives. The little horned larks kept on chipping and crying, for they did not know the meaning of the distant caw of the crows. A warning note from Eremophila silenced them.
In the forest, Bicolor, the mate of Parus, the titmouse, sat silently on her six eggs. She heard the rasping voice of Corvus, but felt safe in her tiny crevice in the maple. Across the clearing, the mate of Sitta, the nuthatch, incubated her five eggs in the hole in the dead beech stub. So important was this period of incubation that even Parus and Sitta felt it. They hunted the trees quietly. Parus stopped to watch for the owl, wondering which way he would fly when the crows finally forced him out.
In the grapevine thicket, the female cardinal was turning her four eggs in her nest of sticks. Richmondena, sitting nearby, paused in his song and listened to the crows. Then he sat silently in the top of the maple and looked toward the stream and the pine roost of the owl.
Bubo flew north, and the crows followed him. The birds heard the screams of Corvus and his friends die away in the distance. The owl had taken his route to the marsh; the creatures of the ancient forest and its surrounding fields were safe for the moment. They relaxed.
In the late afternoon, Otus, the screech owl, called. He was carrying a field mouse to the hollow beech where his owlets awaited him. The five fluffy youngsters pushed into the doorway when he called and huffed and rasped like old machinery.
Down in the brome grass in the pasture swamp, a small brown bird sat motionless on her eggs. The nights and days had come and gone with each minute scheduled. The incubation rhythm of each day took her to feed and bathe and then she returned to incubate. About eighty per cent of her time was spent on the nest. Melodia, the song sparrow, was now reaching the end of this cons
tant routine.
Within the eggs, a wondrous development was taking place. The single cell of each egg had divided and redivided until the new cells were arranged in the embryonic pattern of a song sparrow—or a cowbird. As if by magic the yolk and albumin disappeared and a young bird took their place. Eyes, beak, head, neck, wings, legs, nerves, arteries, intestines, feathers—all were there, where only a few days before there seemed to be nothing.
On the eleventh day the young birds started their escape. A tiny egg tooth on the bird was the tool the young bird used in freeing itself. On the outside of the egg a cracked mound appeared at the large end. Melodia felt the change, and she lifted her head and looked excitedly at the stems of the grasses that had become so familiar to her during the past weeks. Then she glanced nervously at the rotted base of a fence post where she had watched a garter snake hide much of the time during the past fortnight. He was not there. Melodia stood up and stepped to the edge of the nest. She looked down on a wobbly wet chick that lay blind and helpless. He was partly in the big half of the eggshell. With a jerky little movement he flopped free. Melodia picked up the empty shell in her bill and flew to the most distant fence post on her territory and dropped it. As she came back she stopped to catch a larva. Before she entered the nest she perched on a raspberry branch and looked for the garter snake. He was not around. Melodia came quietly to the rim of the nest and stuffed the larva in the fragile mouth of the newly hatched bird. She sat down gently over the nest.
About noon she stood up again. Another tiny nestling had broken out of its shell. He was somewhat larger and sturdier, but still the head of the tiny cowbird rolled weakly on his spidery neck. The bulging eyes were sealed and the bulbous body was sparsely flecked with wet down. Melodia carried the shell halves away.
It was afternoon. Melodia was brooding her tiny young. Suddenly she became as immobile as the earth clod by her nest. The garter snake was returning from the pasture. He slid up to the fence post, paused, then slipped down his route to a retreat under the cherry stump. Melodia waited. She remained motionless for a half hour before she flew off to join Melospiza. They fed in the hayfields together.