Part 7

Vocal music bulks large in our avian springtime chorus, but don't overlook the instrumental music that accompanies it. The drumming of the downy woodpecker on the dead limb of a maple near my bedroom window is as much a part of my spring as is the cheery cheerup of our robin. It's not that woodpeckers are voiceless that they drum. The flicker can be called in with his particularly rich repertoire to repudiate it vociferously. All day the downy woodpecker goes about pounding his head against tree trunks, with his bill chiseling out wood-boring insects to eat. What more natural when springtime comes and he wants to tell the world, and especially other woodpeckers about it, to select a dead limb with a nice tone in my maple tree and hammer out a rolling tattoo--his love song and his challenge.

A DRUMMER The gray-brown ruffed grouse of a wood lot we used to have in the Chicago area is a drummer I miss. "Thump-thump ..." he started slowly, and then quickened to a roll that filled the forest with hollow sound and you wondered whence it came, unless you happened to know, as I did, that an old log in the patch of gray birch was the old cock's favorite performing stand. There he came to roll out his invitation to the demure hen grouse. A drummer, I've called him, yet he has no drum. It's his wings, striking the air, that thump and build up into a roll, its volume testifying to his great breast muscles as well as does the whir of wings as he hurtles away through the air when I come too close.

The snipe of a nearby marsh makes music with feathers and wind, music that is more enthralling to me than the song of the yellowthroat or the vocal imitation of stake driving by the bittern. Circling high, then with a change of pace, his "winnowing" or "bleating" spring song comes drifting down. There is still room for argument, but probably it's air rushing past the outer tail feathers that makes the sound. One year a short-eared owl nested in the nearby meadow. Owls generally are vocalists, even if we don't rate very high their hoots or yelps, but the short-eared owl also has an instrumental performance. Sometimes, when giving his mating song on the wing, a series of "toots," he interrupted this by a dive in which he brought his wings together under his body, with a clapping sound. It's part of the performance, but not, as might be said, the owl applauding his own show.

Over our public school each evening in early summer a nighthawk booms. He has a voice, and he uses it, calling "beep" as he circles high. But the climax of his performance is instrumental, wind on feathers. He heads down, wings high, toward the flat gravel roof on which his mate is sitting. As he approaches the roof he moves his wings down; the air rushing past the quills gives a tearing boom as he comes out of the dive and mounts skyward again.

At dusk, at a damp corner of our old wood lot, in the spring, I listened for the woodcock's flight song, a twittering of wing music as he circles up, and sweet music, too, for a wild fowler's ears, is the whistling of the wings of a passing pair of black ducks on their way in the early darkness.

CONDITIONING IN BIRDS

The classical experiment in conditioning and reflexes is that of Pavlov. It consisted of sounding a bell each time food was given to a dog. Finally the salivary response resulted even when the bell was rung, without the food being given to the dog. The dog was _conditioned_ to the bell. First it had responded to the food, then to the food and the bell, and finally to the bell alone, by a flow of saliva. The beauty of this experiment is in its simplicity, dealing as it does with a single reflex.

Though much behavior is more complex, experiments have been worked out to show how the environment, in a broad sense, can influence inherited behavior. An illuminating example of this is the one I made dealing with young loggerhead shrikes and the duration of their infantile behavior. Young shrikes, as with young passerine birds in general, while in the nest are fed directly by the parents, who place food in their mouths. One of the earliest behavior patterns these young birds perform is to stretch up with widely opened mouth, fluttering wings, and buzzing calls, in anticipation of being fed. This we call begging. Though typically infantile behavior, it may reappear in courtship, but this latter we will not consider here.

Ordinarily this infantile begging behavior is discontinued shortly after the young birds leave the nest and become able to feed themselves. Observations indicate that in a state of nature this change is probably hastened in part by the young birds themselves, who come to avoid having food thrust down their gullets, and prefer to pick up the food for themselves, and in part by the waning interest of the parents in the young, which confers an advantage on the young who early become self-supporting.

CASE OF RETARDED DEVELOPMENT Certain observations made from time to time have indicated that though the age at which young birds changed from infantile begging for food to self-supporting independence was a fixed thing, started by instinct, certain external factors, notably the amount of care the young received, could affect the age at which this change occurred. Indeed there was a record of a young cedar waxwing raised by hand who never learned to feed itself.

When I secured a brood of four young loggerhead shrikes, or butcherbirds, the material was available to conduct a controlled experiment. The young birds were raised together by hand to the stage where they were ready to begin to pick up things, to feed themselves, and to begin to abandon their infantile behavior of begging for food. This was when they were twenty-one days old. They were then divided into two lots and housed separately. One couple had a supply of food kept in front of them, and hand feeding was gradually discontinued and stopped as soon as possible. At the age of twenty-eight days they fed themselves well, though they still begged freely when I approached. By the time they were thirty-nine days old they begged rarely, and after the age of forty-five days they were not seen to beg.

The other couple had no free food available at any time, and they were fed completely by hand, the food being placed in their mouths. At the age of twenty-eight days they had made no effort to feed themselves. By the time they were fifty-three days old they made efforts to feed themselves, trying to peck the food from the fingers instead of having it thrust into their mouths, and evidently would have changed quickly to independent self-feeding and abandoned their infantile begging behavior. But hand feeding was continued. At the age of seven and a half months, when the experiment was discontinued, though these birds were capable of feeding themselves, as was seen when food was accidentally dropped on the floor of their cage, they still begged for food from their human foster parent.

OBJECT LESSON FOR PARENTS These four birds used in this experiment were nestmates, and had similar heredity and early environment. The birds in the lot which received only enough care to ensure proper development became self-feeding, independent, and lost their infantile begging behavior when they were about a month and a half old. The other lot, which received an excessive amount of care in the latter part of infancy, and were hand fed without being allowed to develop the behavior that would have made them independent, retained the infantile behavior pattern of begging to be fed until the end of the experiment. They were then seven and a half months old, and their nestmates, under a different set of conditions, had lost their infantile behavior six months earlier.

With some birds it appears excessive care can be a conditioning factor. It can delay the loss of infantile behavior and the acquiring of the normal independence. Though instinctively the young shrikes tried to develop their independent behavior, when this was not possible they continued their dependent, conditioned behavior.

POISONOUS BIRDS

Poison we know perhaps best in the plant world, whence comes, for example, strychnine. The deadly nightshade, a common weed, is another well-known poison plant. In the animal world we know poison best as something that is injected into the body by stings of bees, bites of spiders, the bites of insects, and even bites of shrews. In addition some animals having irritating, bad-tasting, or poisonous secretions which presumably protect the possessor from predators. This has received most attention in the insect world, the bad-tasting grasshoppers being examples. Toads have an acrid secretion from their skins which deters many would-be toad eaters, and pickerel frogs have somewhat the same thing.

The following three birds, which are recorded as having poisonous flesh, are, strangely enough, all members of groups ordinarily considered good table birds. Further, it seems the poisonous properties of their flesh are not constant, but apparently depend on what they have been eating.

The ruffed grouse of the United States is regarded by many as the finest of upland game birds and favored by the epicure. However, Mr. E. H. Forbush, in his monumental _Birds of Massachusetts and Other New England States_, gives accounts to show that in winter the ruffed grouse is known to eat leaves of laurel, which have poisonous properties, and that there are stories of serious poisoning resulting from eating the flesh of the birds. Such poisoning, Forbush points out, seems to have taken place only long ago and only by winter-taken birds. Perhaps now that it is illegal to shoot grouse in the winter when they may have been feeding on laurel, such poisoning does not occur. This seems an additional reason for obeying the game laws.

Pigeons in the tropics are abundant both as to individuals and as to species and many are favored as food. However, Messrs. D. L. Serventy and H. M. Mitchell, in their recent volume on the birds of Western Australia, report that bronze-wing pigeons of two species are given to feeding on the seeds of the box-poison plant, and when they have been feeding on these seeds their entrails and bones, but not the flesh, are poisonous to dogs and cats. The effects of eating this poison seems to be that the dogs and cats have fits, become mad, bite at anyone within reach, and finally die in convulsions.

During Colonel Meinertzhagen's study of the birds of Mauritius he found that one of the pigeons there had a bad reputation from a culinary point of view. Reports have it that some of the people who have eaten the flesh of this pigeon suffered from extreme lassitude, while others reported the effects as convulsions. Strangely some of the people who reported sickness from eating this pigeon say it tastes well, while others who have eaten it without ill effects say that the flesh is bitter.

KINGFISHERS ON THE TELEPHONE

"What color is the kingfisher? Not the American one, but the European and Asiatic one? My husband is painting one and needs to know the colors," a lady's voice came over the telephone. I thought quickly. "Will it help if I explain the various kinds and colors of kingfishers and where they live? But no, lessons on taxonomy and zoogeography fall too flat most of the time." The lady's voice had a Central European quality. To her "the kingfisher" probably meant the little sparrow-sized kingfisher of the Old World scientists know as _Alcedo atthis_. So I'd better start with that. I described the cobalt-blue back, with darker wings, and dark bars on the crown; an earth-brown stripe through the side of the head, paling to whitish posteriorly, and with ocherous underparts.

"What color is the eye?"

"Brown."

"And the feet?"

"Red."

"And the nails?"

"Black."

She thanked me prettily. I tried to tell her about some of the other kingfishers, but she said no, she had enough, and hung up.

I sighed and thought regretfully of all the other things I had ready to tell her.

In the United States we think of the kingfisher as the belted kingfisher, larger than a jay, with a tousled crest and a voice like a watchman's rattle. But there are other species farther south in the Americas, and in the Old World there are still more. The tropics are their home. Only one species reaches Northern United States, and only one reaches Britain. But in New Guinea, for instance, there are about twenty-four of the ninety or so known kinds of kingfishers; the smallest tiny as a warbler, the largest nearly crow size.

Kingfishers, we call them, but many live on the dry land, and instead of catching fish catch insects or other tiny animals from the ground. One large species, with a broad shovel-like bill, is even reputed to dig in the earth to get its food of earthworms.

They all look much alike in shape. Once you overcome your surprise at seeing a kingfisher as big as a crow, or smaller than a sparrow, you recognize one anywhere--big-headed, large-billed birds with tiny feet that sit up quietly much of the time. Blue is a common color, but not all are blue. Some are generally reddish in color, some patterned with browns, grays, and whites tinged with blue. Many are decorated with crests, and a few species have elongated spatulate-tipped central tail feathers that have earned the species the name paradise kingfishers.

Its voice has given one species its name: the laughing jackass, the jackass kingfisher, or the kookaburra of Australia. "Ha ha huh huh ho ha ha huk" in a deafening chorus has been given as a description of its call. A. H. S. Lucas and W. H. D. Le Souëf, no doubt with tongue in cheek, record that "_on dit_ that the jackass has been heard to laugh while a cicada [it had eaten whole] has been skirring inside him."

CLASSICAL ALLUSIONS Halcyon, Alcyone, and Ceyx appear in the scientific names of kingfishers. Scientific names make the layman shudder. Latin, he says, and if he's told they're not Latin, but rather Greek, it doesn't help any. But once you know the story of Halcyon (or Alcyone) and Ceyx, the names stick in your mind. In ancient times Halcyon was the daughter of Aeolus. And in grief for her drowned husband, Ceyx, she threw herself into the sea. The gods, out of compassion, changed both into kingfishers. Halcyon was also used by the Greeks as a name for the kingfisher and it was fabled to make its nest on the sea, and to quiet the waves for its incubation period. Poets still use Halcyon for the kingfishers in reference to calm, happy, peaceful days, Halcyon days; the sort of days in which the kingfishers can nest on the quiet waves.

The lady had not waited for all this. She had gone. I would have liked to see the picture her husband was painting when it was finished.

ON IDENTIFYING SEA SERPENTS

The lock ness monster reappears periodically in the newspapers. This monster seems to belong in the general category of "sea serpent." As a museum zoologist I've had little to do with such things. The stock in trade of a museum is specimens and if someone sends us a "sea serpent" (and I don't mean a water snake or a sea snake), we'll identify it. If it doesn't have a name we'll give it one and make a place for it in our classification. Until then we are aloof. We've had some little experience at times with "sea serpents" and the following will illustrate the sort of investigation and the results that we've had.

Years ago Sir Frederick Jackson was an administrator in East Africa. In addition to his official duties he was an enthusiastic and an able naturalist. So when a "sea serpent" was reported there he investigated.

IN KENYA The sea serpent was said to frequent Lake Naivasha in the Rift Valley of Kenya Colony. Up until 1909 there were many rumors of it, and Europeans had seen it with their own eyes. It always appeared on the lake about the same time each day, about five o'clock in the afternoon, always about the same distance from the shore, and was always traveling in the same direction, from north to south. All descriptions agreed that it was long, black, and reptilelike, and that it kept appearing and disappearing on the surface of the water at short intervals.

Sir Frederick kept watch with one of the people who had reported it. And, sure enough, what appeared like a long black reptile appearing and disappearing, or like a school of porpoises, rising and disappearing, came into view. But Sir Frederick had binoculars and was able to make out that what to other people had been a long black reptile was in reality a long line of white-breasted cormorants in flight, on their way to their roosting quarters. As they flapped steadily along they were plainly evident, to the naked eye, as a moving black line; as they paused in their flapping and sailed on motionless wings they became invisible to the naked eye, though, of course, still visible through the binoculars.

IN NEW GUINEA Once, for a few startled moments, I thought I had a sea serpent before my very eyes. It was on the middle Fly River in south New Guinea. We were camped on a bamboo-covered bluff overlooking the river. Though about one hundred miles from the mouth, the tide made itself strongly felt here, and there was an abundance of driftwood. This driftwood, varying from freshly uprooted trees that had fallen into the river to waterlogged timber that had been long in the river, went up and down on the tide until it got out in the main channel and so on to the sea. One day at lunch, sitting in front of my tent, I was idly watching the driftwood. One piece in particular caught my fancy. Apparently it was the root of a partly submerged log, projecting about three feet above the water, and curved at the end so that it looked like the neck and head of a reptile with a casque on its head. Knowing it was a waterworn root, in fancy I even saw its eye. I called my companion's attention to it, as here was as close as we were ever likely to get to a sea serpent. Then, the "head" turned. It was alive. For a few startled moments it was a sea serpent. You can imagine our amazement at having a piece of driftwood that we had in fancy turned into a sea serpent come to life. Investigation became the order of the day. The binoculars that were constantly at hand were trained on it. The reality came as a further surprise. Our sea serpent was the head and shoulders of a cassowary which was swimming the river. Later I found that these large, ostrichlike birds, which have a large casque on their heads, are well known to swim, but I didn't then.

This seemed an ideal opportunity to collect a specimen. These birds may weigh up to 150 pounds. When shot in the forest there is the question of lugging them perhaps miles to camp. Here was one swimming up to our door.

We sat quietly waiting for it. But our native boys had seen it too, for next I saw them rowing the dinghy to it. An oar was brought into play to stun it. And then both the boys and ourselves found out something else. Dead cassowaries sink. When the bird was stunned by a blow of an oar, it disappeared below the surface and was never seen again.

CONSERVATION OVER THE TELEPHONE

Richard Orr, the _Tribune_ reporter, called me one day about bronze grackles. It seems that the Chicago _Tribune_, in their "Day by Day on the Farm," had told about the grackles on the _Tribune_ farm. A _Tribune_ reader wrote in, expressing surprise that grackles were permitted on the _Tribune_ farm and gave details of destruction by grackles of other birds, personally observed. What were the facts of the case? Should grackles be tolerated? Or should they be eliminated? Orr wanted to know.

This is the sort of question that is difficult. It is important, too, for it involves basic conservation issues. And there is no sharp, clear-cut yes-or-no answer. The question as to the grackle's character reminds me of the character of Moses, as explained when I was in school by a professor of the Bible: The black was there and the white was there; Moses was a character sketch in gray. And so with most creatures. They're both good and bad from our standpoint. Grackles certainly do kill other birds at times, and interrupt the nesting of some of our favorite songbirds. And yet, liking birds as I do, I tolerate them in my garden. On a trumpet vine on our garage in Chesterton, Indiana, one year we had a grackle build its nest on top of a domed English-sparrow nest. The young of both sparrows and grackles hatched about the same time, and the two families, within six inches of each other, were successfully raised without friction between the parents.

Quite evidently grackles are not always killers of other birds. As to robins or grackles being the "better" birds, if we had a robin's nest that we prized, and the grackle killed the young in it, the grackle would be "bad." But if we were an inquiring farmer, and had to weigh the grackle against the robin, we might find the grackle "good" and the robin "bad." The grackle feeds its young vast quantities of insects harmful to the gardener; the robin sometimes seems to specialize in earthworms. Earthworms are beneficial to man, passing through the earth, making air and water more accessible, and, by passing earth and vegetable matter through their intestines, enrich the soil.

The house wren that warned the _Tribune_ reader when the grackles were about is often prized as a garden bird; it is bold, saucy in appearance, and a vigorous songster. But it is also well known as a quarrelsome bird, prone to punch holes in the eggs of its neighbors, and it also may fill up with sticks nesting boxes so that other birds cannot use them.

The above was the gist of what I told Orr, and appeared in the May 5, 1950, _Tribune_.

Thinking of it afterwards, as is usual, I thought of many other things I could have said, and perhaps made more clear that no bird is all good or all bad, from our human point of view. Their relationships with the rest of the landscape are complex. I like to see butterflies flit about my garden. But butterflies are caterpillars at one stage. And caterpillars may eat some of the things in my garden. But some birds feed on caterpillars. If I eliminate the caterpillars because they eat the plants I like, at one stroke I eliminate the source of the butterflies I like, and food for some birds I also like.

Perhaps the partial answer, if answer there be in this imperfect world, is summed up by moderation: I can have some butterflies, some caterpillars, some plants, and some birds in my garden. If one becomes too abundant and interferes with the others, I prune it. Maintaining some sort of a balance, we can have some of each.

BIRDS WASHING FOOD

We not only wash ourselves and our clothes, but certain items of our food are regularly washed, as spinach, to get the sand out of it. Washing has been so important in our society that we've coined the term "Cleanliness is next to godliness." Possibly we've the snobbish idea it's a strictly human trait. Among other animals we don't expect to find water used for such cleanliness, and the raccoon, who does wash his food, is considered a sort of biological oddity.

But when we come to birds we find a surprising number of them that wash their food.

The dipper of our Western mountains in Oregon has been seen to wash insects and grubs before feeding them to the young birds. The parents held the food crosswise in the bill and the head was twisted rapidly from side to side in the water. Not until then was the food taken to the nest for the young.

The scene shifts to Africa. Four buff-backed herons were feeding on a flooded lawn at Gezira, Egypt. One of the birds captured a large insect, apparently a large black beetle. Holding the insect in the tip of its bill, the bird walked to the water, immersed the beetle three times, shaking and fumbling with it the while, and then swallowing it.