Chapter III: Introduction (2)

The birds that do this are fowl-like birds of the Australasian area. They are variously called "mound builders" from the nest mound they construct, "megapodes" from the large size of their scratching feet, or bush turkeys, presumably from their edible qualities. These birds bury their eggs and leave them thus to hatch without any brooding by the bird. The birds have adapted their habits to two different sources of natural heat. On some of the Pacific islands there is local volcanism making the sand warm. To such places the birds come to bury their eggs.

But in many of the tropical forests there is not this convenient natural heat. Another method is employed. The birds take advantage of the heat generated by rotting vegetation. They scratch up the surface litter of the forest floor into mounds--structures that may be a yard or two high and five or six yards across. Some much larger have been observed. It is into these the hens burrow and lay their eggs. The temperatures in them have been recorded as 95° to 96° F., which compares with normal bird temperatures of just over 100° (bird temperatures are a few degrees higher than normal human temperature).

The bush turkeys from Queensland have been bred in captivity, and have given some extremely interesting data, according to an article by Mr. Coles in the proceedings of the Zoological Society of London for 1937. It was the male who did all the building of the mound. Though the female started to cover the eggs laid singly in burrows in the mound, the male finished this. And it was the male that looked after the nest mound during the incubation period, continually scratching over the surface layer. Both parents helped the young emerge, by digging burrows into the mound which the emerging young, who had started to burrow out, could use.

The young are in a very advanced state and apparently are able to fly and look after themselves upon emerging. On the day after hatching one chick is reported as able to flutter up to a perch six feet high. In the captive birds mentioned above, the parents, though they were attending to the mound and helped the chick out, appeared to take no further interest in the chick once it was out.

There are a few other cases when birds cover or bury their eggs. With the grebes it has been said they covered them and left them to be incubated, but that is doubtful. Certainly the megapodes are the only ones to present a dear case of "artificial" incubation.

This burying of eggs by the megapodes of course brings to mind the way some reptiles, such as turtles, bury their eggs. And considering that from an evolutionary viewpoint birds are really only modified reptiles, it is perhaps not surprising that they too have this habit. But that it is really an ancestral trait retained by the megapodes is doubtful. Rather I'm inclined to think it's another example of the many ways birds have evolved, or changed their habits so as to utilize as much of the environment as they can in as many ways as possible.

CORMORANT FISHING

In western Europe, when falconry was in favor for taking game on land and in the air, there was a certain vogue for training cormorants to take fish. Like the falcons, the cormorants were hooded and carried on the wrist, but of course where the falcons flew to their game, the cormorants swam to theirs.

It was in China where cormorants were domesticated, "completely and perfectly," as that eminent Sinologist Dr. Laufer says. Extensive breeding establishments have been maintained. The eggs of the breeding flock of cormorants are given to a hen to hatch, for cormorants as mothers prove unsatisfactory under domestication. When the eggs hatch the young cormorants must have special care; for, unlike the young of ducks and geese, young cormorants at hatching are not down-covered and able to run about, but are weak, helpless things sensitive to cold. They are placed in cotton batting, artificial heat provided when necessary, and they are fed by hand on a diet composed basically of chopped eel.

Finally the young are full grown and fully feathered. The training is now started. First the young are tied to a stake at the water's edge. A whistle signal is given and the young cormorant is pushed into the water. Thus he learns to know and obey the signal to go into the water. Then the trainer throws him little fish. These the cormorant catches in its beak and when he does the trainer whistles another signal, to bring the bird back to him with the fish. And the cord tied to the bird is used to demonstrate what is meant and make sure its done. So the training goes on until the bird has graduated to a class taught from a boat. Sometimes a small float is attached to the cormorant by a short cord, and it can be drawn in with a bamboo hook. If young birds are trained in the company of trained birds, it takes but half as long. Finally the training is complete and the fisherman sets out with his birds. This is no sporting event; it is the serious business of life, getting a living from fishing. On the sampan or the bamboo raft there may be from two to a dozen birds; sometimes they may have special perches built for them along each side of the boat. Sometimes the cormorant has a cord or band around its neck. The reason for this is disputed. Some say its a place to attach a cord; a place to get hold of the bird; some say each man's cormorant is thus specially marked for identification; some that it's to prevent the bird from swallowing its prey. With well-trained cormorants it is sometimes dispensed with. At a signal the cormorants go into the water, swim, and dive seeking fish. The fisherman, by stamping his feet, by voice or whistle, and by hitting the water with a bamboo directs and encourages the birds. When the cormorant catches a fish it brings it back to the boat, and the fisherman may use a net, or may lift up the cormorant onto the boat on an oar or pole, and take the fish from the bird. If a bird is lazy it's encouraged by beating the water near it with a bamboo pole. As cormorants' plumage is only partly waterproof they cannot stay in the water indefinitely, and this, as well as fatigue, probably determines the rest periods when the birds are lifted aboard. Sometimes the fisherman helps attract fish to the boat for the cormorants to catch by scattering grains of rice in the water.

When the day is finished the cormorants are collected, fed, and the fisherman goes home with the sustenance for his family, gathered by a bird.

In Japan the cormorant is also used, but apparently somewhat differently. There cormorant fishing may partake of the nature of a sport. Sometimes the cormorants are "harnessed" into a team, each attached by a cord to a single line, directed by one master. In China the fishing is usually done during the day, but in Japan night fishing is common, the scene being illuminated by fires in braziers or cressets on the boat, or lanterns.

THE SHRIKE'S LARDER

Our northern shrike is a songbird which has developed feeding habits along the lines of those of a hawk. Whereas most birds its size are content with fruits, seeds, or insects of a size it can beat or bite and then swallow whole, our northern shrike takes not only small insects but prefers large ones, and mice and birds too big to be swallowed whole. It is an opportunist and takes what is most abundant and easily accessible. The shrike's strong hooked bill is a powerful weapon, used with a nipping motion that is directed at the back of the head or neck of mouse or bird.

Now with the dead sparrow or mouse the shrike is at a disadvantage. With a powerful bill hooked at the tip its feet are still those of a songbird and are not strong enough to hold its large prey while pulling it to pieces. Only small insects are held in one foot and pulled to pieces. To meet this need for holding large dead prey the impaling habit was evolved. The result of this is the so-called larders, which form a fancied resemblance to meat hanging in a butcher shop, and have given the birds their name of butcherbird. A thorn tree, a splintered end of a branch, or even the barbs of wire fencing may serve. The shrike flies to one of these, carrying the prey in its bill (rarely in its feet), and with a pulling motion fixes the prey on a projection point. Sometimes instead of impaling the mouse or bird it pulls it into the fork of a branch, and so wedges it there. Now the food is firmly held, and the shrike can use its bill effectively to pull off pieces of flesh and swallow them. When the bird has fed, it leaves the rest of the animal hanging where it was. It may return to this food and make repeated meals of it if not spoiled, or dried up, until the whole is devoured. But often parts of meals are left hanging and discarded. If suitable thorn bushes are scarce the shrike may return time after time to the same tree with its prey, and in time this tree may come to be decked with many partly devoured carcasses. Such trees are the so-called "larders." There is another aspect of shrike behavior that adds to these larders. The shrike, even when replete, may seize any prey that appears and impale it. The bird's organization is such that the sight of a small moving animal may start the actions that end with impalement even when the bird is not hungry. This food usually is not eaten later.

Thus the shrike's "butcher shop" is not primarily a store of food, even though it sometimes serves as such when in times of scarcity remains of old meals are eaten. It is not a gathering of food in time of plenty and saving it for a later use. Rather the placing of many items in one tree is the result of its being a favorable impaling place. And the impaling is behavior developed to overcome the weakness of the claws in a bird whose disposition and strong beak enable it to prey habitually on larger animals which otherwise it could not tear to pieces and eat.

BIRD FLAVORS

Particularly in the study of insects it has been shown that bright or contrasting and conspicuous colors tend to be associated with ill-flavor in the animals that wear them, while insects with a good flavor tend to be so colored that they are difficult to see. The first is a warning coloration--advertising to a predator that he will not enjoy eating this insect and better leave it alone; the other is concealing color, its function apparently to keep predators from finding their prey. The tasters in the experiments that have been used to work out the above generalizations were usually birds, but, as checks, a variety of other animals were used, and the magpie moth (_Abraxas grossulariata_), for instance, was found to be distasteful to certain spiders, frogs, lizards, various birds, a bat, and finally "the late Dr. Hans Gadow (one of the leading ornithologists of his day), who made a practice of sampling caterpillars, remarked on trying an _A. grossulariata_ that it was quite one of the worst he had ever eaten!" Apparently ideas in taste are similar throughout large sections of the predatory animal world. Reversing the usual role, and using insects (hornets) as tasters of bird flesh, the celebrated British naturalist, Dr. H. B. Cott, has recently studied the question of the palatability in birds and their coloration. Naturally Dr. Cott, with his customary thoroughness, compared hornets as tasters with other animals, including cats and men, and found a surprisingly close agreement in the results.

The experimental procedure was to expose the flesh of two different birds (without feathers) at the same time, and see which the wasps ate first. Thus a graded series was built up of the 38 species of birds tested, with a palatability rating of from 1 to 38. The wryneck and the crested lark stood at the top of the list, and the pied kingfisher and the white-rumped black chat, as the least palatable, at the bottom with Numbers 37 and 38.

Then, surveying the coloration of the birds, and their habits, Dr. Cott made the important correlation that in general the birds whose flesh was most edible were protectively colored, and those whose flesh was least palatable tended to be conspicuous in color and behavior!

To relate it to the theory of evolution Cott concludes that selective pressure by predators seems to have forced vulnerable species along two divergent lines of specialization: leading in those which are relatively palatable toward concealment, and in those which are relatively distasteful toward advertisement.

HOW MANY FEATHERS HAS A BIRD?

The question as to the number of feathers on a bird seems a simple one without complication. Dr. Wetmore, the well-known ornithologist who was secretary of the Smithsonian Institute, has given us some data. The number varies with the species, of course: the smallest bird, a hummingbird from Cuba, had the fewest, 940 feathers; larger birds had more, the robin 2587, and the mourning dove 2635 feathers. A glaucous-winged gull had 6540; a mallard 11,903 feathers; a Plymouth Rock chicken was said to have 8325 feathers; and a later investigator reported 25,216 feathers on a swan.

But as one thinks of it, more questions arise, as in any investigation. The answer to one question poses two more. The first question is, do not the birds in winter need a wanner plumage to keep out the cold than they do in summer, when it is warm? Do they have more feathers then? This was definitely true in the case of the goldfinch: a bird in summer dress had only 1439 feathers, while one in winter plumage had 2368 feathers, obviously an adaptation for cold weather.

The next question is more abstruse, but eminently practical: the smaller a body, the larger exposed surface for its weight it presents. That is, for its weight a small bird has a proportionately much greater surface from which heat is lost than does a larger one. With equal heat-producing mechanism and metabolism, a small bird would need more insulation than a large one. Reduced to its simplest: one would expect small birds to have relatively more feathers than large ones: more feathers per gram of weight. Is this true? Two members of the Department of Poultry Husbandry at Cornell University, Dr. F. B. Hutt and Lelah Ball, supplied the answer. Small birds do have more feathers per gram of body weight than do larger ones. A hummingbird weighing 2.8 grams had 940 feathers or 335 feathers per gram; a nighthawk weighing 67.9 grams had 2034 feathers or 29 feathers per gram; while a swan weighing 6123 grams had 25,216 feathers or 4 feathers per gram of body weight.

Presumably there are still other relations: Do the birds that live in the tropics where it is warm have fewer feathers than species of the same size of arctic climates, as one would expect? Are certain types of feathers such as those of aquatic birds better insulated than those of land birds, so that the bird requires fewer of them to keep warm? Does a dense coat of down reduce the number of feathers needed to keep warm? Do the loose feathers of ostriches, lacking barbules, necessitate some adjustment in numbers? The things we've learned point the way to other questions to be investigated.

LAST YEAR'S BIRDS' NESTS

The wisdom of our fathers is sometimes embodied in what we call old saws, to wit, "Many hands make light work," to which the iconoclast retorts, "Too many cooks spoil the broth." And when we come to the phrase, "As useless as a last year's bird's nest," we must reply, "Circumstances alter cases." For many a bird's nest of yesteryear still has its use; some a biological use to other birds; some to feed and clothe man.

SUBLEASES The snug, secure cavity that a woodpecker chisels in some tree trunk for its nest will last for many years, a shelter in which tree swallows, house wrens, screech owls, bluebirds, or wood mice may make headquarters and use as a nursery. In the strange forests of saguaro, a giant cactus of southern Arizona, the nest cavities of the gila woodpeckers and the gilded flickers in the cactus trunks seem necessary for the presence of many nesting birds. Without them the birds would have to go elsewhere for cavities in which to nest. In old woodpecker nest cavities the elf owl, pigmy owl, screech owl, sparrow hawk, ash-throated flycatcher, martin, and crested flycatcher commonly nest, and cactus wrens and even Lucy's warbler may use them. Their use is not confined to birds alone, for scaly lizards, snakes, rats, and mice have been found in them. In the Argentine there is a woodhewer that appears to depend on the domed mud nest of the red oven-bird for its nesting sites. It takes over a recently vacated or an old nest of the oven-bird and lines it with grass and feathers for its own use. In Africa and Madagascar the great domed nest of the hammerkop stork may find a secondary use in sheltering barn owls.

SANDPIPERS AND EAGLES But it is not only burrows and domed nests that when deserted by their original occupants are used by other birds. The solitary sandpiper of our northlands belongs to a group in which nest building is reduced to a minimum, usually little more than a hollow in the ground with a few bits of material added. But the solitary sandpiper, and the green sandpiper of the Old World have broken with tradition and customarily lay their eggs in the abandoned nest of some thrush. Our great homed owl is another bird that may use the discarded nest of a crow or hawk for its eggs and young. And age in the eagle's nest means little to the eagle. Frances Herrick, the noted chronicler of the life of the American bald eagle, writes of one nest in the crotch of a lofty tree that had been in use for thirty-six years. Each year more material was added until the nest became 12 feet high, 8½ feet across the top, and was estimated to weigh 2 tons.

Man has found, among others, the following two direct uses for two kinds of birds' nests: one he uses for food; of another he makes covering for himself.

The swift's nests used for food have been discussed in another chapter, "Birds' Nests and Their Soup," so here I will only tell of the use of birds' nests as human covering.

EIDER-DOWN BLANKETS An eider-down has come to mean a comforter, a sleeping bag, or even a padded jacket. But to an ornithologist eider down still has its older meaning: the down of an eider duck. It is this material gathered from the eider ducks' nests which forms the article of commerce. The eider's nest may contain grass, seaweed, and sticks, but it is notable for the blanket of down on which the eggs rest, and with which the female covers the eggs when she leaves them. This down is plucked from the breast of the female. If it is taken from the nest she replaces it with more, and it is on this principle that harvesting of the down is carried out. On islands and islets in the northern part of the North Atlantic eiders nest in great numbers in dense colonies. Some of these are jealously guarded by the local inhabitants, who gather the first blanket of down from the eggs, and later, after the eggs have hatched, gather the second crop of down with which the female has replaced the first to guard her eggs against the inclement weather of those boreal latitudes. Each nest may yield an ounce or so of the precious down, which is carefully cleaned and sent to market. It is this material, extremely light, extremely elastic, and one of the best non-conductors of heat, which finally becomes the important part of real eider-down comforters, sleeping bags, and padded jackets.

SYMBIOSIS--ANIMALS LIVING IN MIXED HOUSEHOLDS

Symbiosis, a term from the Greek, is what the biologist uses for the living together of two dissimilar organisms. In a broad sense it includes such diverse relations as the lice living on man and rats in his house, the union of an alga and a fungus to form a lichen, and the cross-pollination of flowers by hummingbirds.

The story of the burrowing owls of our Western plains living in amity with prairie dogs and rattlesnakes as one happy family comes to mind as an example. But "foolish nonsense" is how the noted biographer of North American birds, A. C. Bent, characterizes such stories. He then goes on to quote evidence as to what actually happens, and one can see how the story originated. The prairie dogs, which are really plump, dumpy, ground squirrels and not dogs at all, dig their burrows close to each other on the prairie in colonies which have come to be called prairie-dog towns, or dog towns or simply "towns." Burrowing owls also take up their residence in these towns, probably because they find burrows ready made and do not have to dig their own as they are quite able to do.

MODERATELY PREDATORY The owls may make an occasional meal of a young prairie dog, and a prairie dog may perhaps dine occasionally on owl eggs, but on the whole owls and dogs get along on terms of easy familiarity. Sometimes when alarmed, both may scuttle into the same burrow for safety, but each has its own burrow. With the rattlesnake it is different. The rattlesnake may live in burrows in the dog town, but when it is hungry it eats owl or dog as occasion offers. While the picture of a happy family of owl, dog, and snake is a myth, the symbiosis of owl and dog, at least in the same colony, is striking.

In Africa there is a tiny falcon only about eight inches long which is called a pygmy falcon because of its small size. When Dr. Friedmann was studying the social weavers in South Africa, birds which nest in large colonies under a common roof they make in a savanna tree, he found these falcons occupying nest chambers in thriving weaver colonies. There was no friction between the weaverbirds and the falcons, and they were sometimes seen to sit side by side. When Friedmann collected three of these falcons he found bird remains in their stomachs but they were not remains of the social weavers. Apparently the falcons were feeding largely on small birds, but they did not molest the weaverbirds which had made the nests the falcons were using.

PARROT-DUCK-OPOSSUM MÉNAGE We occasionally find a mallard nesting in a tree, on an old crow or hawk nest, and there are ducks like the wood duck and the golden-eye, which usually nest in holes in trees, but a South American duck called the tree teal habitually nests in a parrot's nest. The parrots, called monk parakeets, make their nests in compact colonies in the branches of trees, so close together that they form a single mass. The tree teal's usual manner of nesting is to lay its eggs in one of the chambers in this apartment-house colony. At first the eggs are laid on the rough twig floor of the nest, but as the eggs increase in number a lining of down, plucked from the breast of the bird, is added until it may even extend out the entrance of the nest. Apparently parrot and duck both get along amicably in their pendant treetop cradles. An opossum sometimes also finds these parrot nests to its liking, though one wonders if it may not have a meal of young parrot or duck in mind. But be that as it may, in different chambers of a single communal nest of these parrots, parrots, a duck, and an opossum have been found.

On islets off the New Zealand coast lives a rather large-sized lizard called _Sphenodon_. It's rather well known by name, at least, for it is one of those relics of a formerly more widespread group which are called living fossils. It is also noted for its remarkable development of a pineal eye, the remnant of an important sense organ in ancestral forms, and formerly an organ some philosophers supposed to be the seat of the soul. But here we are interested in the fact that petrels swarm to these same islands to dig their burrows and lay their eggs in them, and it is in these same burrows that _Sphenodon_ spends its daylight hours. Apparently the insect-eating _Sphenodon_ and the oceanic-feeding petrels share the burrows amicably, adding still another example of a rather long list of dissimilar organisms whose lives are associated.

BIRD APARTMENT HOUSES

Every now and then in our press appear blasts against crowded living conditions in our cities, and the tenements where people are crowded together. Often there is the implication that this type of thing is unnatural and abnormal. And yet when we look about us in the bird world we see that gregariousness is a common trait. We have only to remember the great flocks of starlings and blackbirds in the autumn, or the massed flights of water fowl. Not only in traveling and in feeding, but also at nesting time birds may gather together, and some birds nest in such close association that the term "apartment houses" or "tenement" is really applicable.

The martins' house on our lawn with perhaps dozens of closely spaced rooms (some houses have as many as two hundred rooms) is a case in point. The neat martin house, made of boards, is a man-made thing, but even before the white man came to this continent, and before the Choctaw Indians hung up groups of hollow gourds for the martin colonies to use, the martins nested in colonies. Even in recent years certain colonies we might consider unprogressive have been reported as using such diverse nesting situations as among the boulders of a lake shore in Minnesota, and the closely spaced woodpecker holes which riddled a dead pine in Florida. And probably it was always thus. The martins liked company at nesting.

CLIFF DWELLERS, TOO Perhaps it would not be proper to consider a colony of bank swallows, each with a separate burrow in the same small cut bank and roofed with the same few square yards of turf of mother earth, as a real apartment house of cliff dwellers. But the term has been used in connection with a West Indian woodpecker, where a dozen pairs were nesting in a single dead tree, and "the trunk was a veritable apartment house." A similar situation exists with the naked-faced barbet of West Africa. This bird too makes a hole in a dead tree for its nest, like a woodpecker, and colonies of thirty to fifty birds may be found nesting in a single dead tree, while other dead trees nearby, apparently equally suitable, are untenanted. Colonies of hundreds of nests of cliff swallows, the nests touching and overlapping, may be under the eaves of a single barn, or as they used to be and some still are, on the sheltered side of a cliff. But as these birds had nothing to do with the making of the roof, perhaps these too do not deserve to be rated as apartment houses.

In southern South America there is a monk parakeet that makes a real tenement. It nests colonially in treetops, and the nests of sticks are placed so close together that they merge and form a single mass, up to nine feet across, in which each parakeet has its own nest. Similar to this is the palm chat. This West Indian bird is small and thrush-sized, dull in color, brownish with a streaked breast, nothing remarkable to look at, but it carries amazingly large sticks, little thinner than a lead pencil and as much as two feet and more long up to the top of a palm tree, and there it makes its bulky community nest.

BUILD NESTS CO-OPERATIVELY These stick nests, which may be four feet and more across, are conspicuous and regular features of the landscape in Hispaniola. The colony consists of four to eight pairs of birds, and each has its own apartment in the bulky structure, and its own passageway to the outside. But in the parts of the community nests that hold the individual nests together and cover them there are roughly defined passages running through the interlacing twigs of the top of the nest so that the birds can creep about under cover. Apparently some of the work is carried on in common, for as many as half a dozen birds may be working close together, pulling and twisting twigs more firmly into place.

The social weaver is the most advanced apartment builder. It, like the palm chat, has little of distinction in its appearance, being mostly dull brownish with a black face. But in its home country, the savannas of Rhodesia in southeastern Africa, its huge community nests in the savanna trees may be seen from afar. The largest Friedmann saw when he was studying the bird there was about 25 feet by 15 feet, by 5 feet high, and contained about 95 nests. And this might have been still bigger, for part of it had broken the branch on which it rested and fallen to the ground. Sir Andrew Smith, the early ornithologist of South Africa, has written that when these birds start a colony they first of all make a roof of coarse grass. The group to which the social weaver belongs gets its name from the remarkable ability some of them have of weaving their nesting materials. But the social weaver neither plaits nor weaves its roof. It puts the roof together in the form of a well-made hayrick with a fairly definite thatching arrangement so that the water runs off. This is a community effort. Under this roof each individual pair makes its own separate nest. These apartment houses are used year after year, but last year's chambers are not used, new ones being made under the roof each year, and so it grows bigger and bigger until the weight of the mass may break the branches and cause a part or the whole to fall to the ground.

BIRD HELPERS AT NESTING TIME

In many a well-run American home the children have definite responsibilities, the older children may help look after the younger, and even grown-up relatives may stay as part of the family group. As in so many cases there may be found parallels to this in the bird world.

The ani, the curious tropical American cuckoo that makes communal nests, is gregarious and the young of the first brood become part of the parent flock. Two more broods may be raised during one season in Cuba, and the young of the earlier brood may feed their younger brothers and sisters of the later brood. The same has been recorded for many other species in the wild: in eastern bluebirds, mountain bluebirds, wheatears, long-tailed titmice, barn swallows, coots, rails, and gallinules young have been recorded as feeding still younger birds. In captivity this habit has been seen a number of times. Young birds hardly able to feed themselves may help feed still younger individuals of the same or other species, and a nestling crowned hornbill has been seen to offer food to its nestmates. This tendency to feed nestmates evidently appears very early in the life of the bird, as Dr. C. O. Whitman, who worked intensively with pigeons at the University of Chicago, recorded a hybrid dove only twelve days old that fed its nestmate.

FIVE JAYS AT A NEST It was rather generally known that occasionally more than the two parent birds attended a nest, but until 1935, when Alexander Skutch, the authority on the biology of Central American birds, published his paper "Helpers at the Nest," few of us realized how widespread this was. Since most birds of a species are difficult to identify individually, one must actually see the extra, unmated helpers at the nest along with the parents to be sure they are there. In the brown jays of Central America that Skutch studied closely the colors of the soft parts, bill, feet, and eye rings were variable and he was able to recognize many individual birds. At five nests he watched he found at least one helper at each nest, and at one there were five helpers, all bringing food. Sometimes, if between an incoming, food-laden bird and the young, they would take the food and pass it on to the nestling. At one nest the unmated helper was more zealous in guarding the nest than were the rightful parents. Sometimes, perhaps, these helpers were unmated young of the parents' previous year's brood, but this could hardly have been the case where there were five helpers, for the brown jay ordinarily raises no more than three young a year. A black-eared bush tit of Central America seems to have a great preponderance of males and at one nest in addition to the parents there were three other males bringing food to the young.

MATERNAL PENGUINS Perhaps the most striking example among birds is the emperor penguin. These birds breed in the dark and cold of the antarctic winter, on the edge of the ice shelf. The single egg is carried on the feet of the brooding bird; indeed one wonders what other adaptation for holding the egg would be possible in this land of ice, snow, and water. Only a few of the adults in each colony lay eggs any year, perhaps one in five, or one in twelve. But all the adults in the colony have the urge to incubate and brood. Thus many old birds, rather than merely the two parents, may take turns caring for each egg or chick, leaving the rest ample time to feed. So strong is the urge to brood that struggles may take place over a chick and it may be very roughly handled. Indeed the chicks may so resent this that they may creep away into ice crevices and freeze to death. Another strange turn this behavior may take is that frozen eggs, dead chicks, and even bumps of ice of suitable size are carried on the feet and covered with the birds' feathers by their "would-be fathers and mothers."

A NAME FOR A BOAT

A request for the name of a sea bird, a name to be used for a boat, came to me at my desk in the museum one day. My memory was quickly exhausted with sea gull, sea swallow, and albatross. But I keep within reach the handy guide, _Birds of the Ocean_, by W. B. Alexander. In the index I found twenty pages of names, two columns to a page. They started with _aalge, Uria_, and went on down through the alphabet to _yelkouan, Puffinus_, and to _zimmermanni, Sterna_.

EUPHONY NEEDED A name should be short, pleasant-sounding, and easy to remember and to say, so obviously such words as _Macronectes_, _Brachyramphus_, _Aptenodytes_, and _Coprotheres_ are ruled out among the scientific names. But further, when choosing a name for a boat from among those of water birds, one should consider the kind of a boat. There should be some appropriateness; some points of resemblance between the boat and the bird, or between the boat owner and the bird. Albatross seems right for a seagoing sailing ship, sailing to southern oceans; tern (or sea swallow) appropriate for light, dainty coastal sailing craft; puffin or auk or murre for power craft, for these birds spend most of their time stolidly on the water and when they fly have a direct buzzing flight. Loon and dabchick would do well for fresh-water boats. But one objection to both them and the various auks for a name is that these birds spend much time swimming underwater. They might better give their names to submarines. The big, stocky sea ducks, called scoters and eiders might suit some stout craft that ply to arctic waters.

SCIENTIFIC NAMES AVAILABLE I reviewed the host of other names. Scientific names need not be ignored either. What is nicer than _Gygis_, the name of the white, fairy, or love tern of the South Seas for a small summer sail boat? Then going farther afield into austral waters for far traveling craft there's _Diomedea_, the name of the albatross, and _Daption_, the medium-sized petrel that also is called pintado for the same reason a white-splashed horse is called a pinto, and _Prion_, the tiny whalebirds of the antarctic whose blue-gray back is near the ideal ocean-camouflage color. _Larus_, a good honest name without frills, belonging to the gulls that haunt our harbors, coasts, and lakes, would do for a plain, everyday sort of boat. Kittiwake is another gull that spends more time at sea. Gannets are boldly black and white, strong-flying birds of the North Atlantic, and one could use that, or its scientific equivalent, _Moris_, for a boat.

Penguin and pelican I'm doubtful about; I can't imagine a boat for either. Skua or jaeger would, of course, be a lovely symbol for a pirate vessel, as would frigate bird; both are birds that practice the stand-and-deliver method of getting food from weaker fisherfolk. The petrels called shearwaters are among the hardiest seagoing birds, but the name has little association for most people beyond wondering if they feed around breakwaters. Petrel itself isn't a bad name, though one might think of the storm petrels, which are also called Mother Carey's chickens, and have been considered the souls of drowned sailors, though their name perhaps refers to Peter, and his attempt to walk on the water, as these birds are continually trying to do.

Phalaropes are snipes of sorts that have taken up a periodic seagoing habit, and their name might often be appropriate. Even their habit of spinning quickly about as they sit on the water might still agree. A Chicago man named his Chris-Craft _Sandpiper_, after, as he said, the bird that goes hopping along the beach before the waves.

_Sula_ is a good sort of a word, and the name of birds that are strong, swift fliers of the tropics. But in English they're usually called booby, which is an English word meaning simpleton (which name the birds got from stupidly perching on ships). _Alle_ for the little auk or dovekie would do for a tiny boat in northern waters, and I knew of one boat called the _Alca_, after the razor-billed auk, while _Cepphus_, the name of the black guillemots, is equally good, as is both _Lunda_ and its equivalent puffin.

Some names have a stark simplicity that would attract few, like shag, used for the cormorant, and muttonbird for a petrel. The cahow people might shy from because for many years we were not sure whether this West Indian petrel was extinct or not.

Myself, there are two names I rather like and I've been saving for the last: for a small sailboat I'd say the _Wideawake_, as the sooty tern is called in its tropical home, and the other, for a larger seagoing boat, is the _Mollymawk_, a sailor's name for the albatross.

WEAVERS AND TAILORS IN THE BIRD WORLD

One can imagine the consternation in trade-union circles when it becomes known that there are, among birds, those who weave and those who sew. Their products are entirely for home consumption and there are no minimum wage, no maximum hours, or any fair-trade or quality agreements. None of the Audubon societies have even touched on the matter.

WEAVING The sewing and the weaving is done entirely in the construction of nests. To take up the weavers first, we can point to the Baltimore oriole, which makes a sac-shaped, pendant nest, often hung from the trailing tips of elm branches. The walls of this sac are formed of fibers pushed and pulled back and forth with the birds' bills in a seeming haphazard way so that a roughly woven or stitched fabric results. But the finest weavers belong to that group of birds known as weaverbirds. One might expect that to be an expert weaver a bird would have to have a slender bill. But no, their bills are short, stout, clumsy-looking, and sparrowlike. And yet these are the birds that weave elaborate pendant nests of fibers and straws. The finest are in shape like an inverted retort, with the nest proper in an oval chamber, fastened to a branch by a special strand of fibers, and with a tube or funnel for an entrance. The walls of these fine weaverbirds' nests are amazingly strongly and neatly woven. In captivity one of the weaverbirds, the red-billed weaver, was studied at its nest building and it was found that the strong, intricate, and beautiful weaving of this species actually included knots of several sorts.

TAILORING The tailoring is done by birds of quite another group. They are Old World warblers of several sorts, some in southern Asia and some in Africa. The tailoring consists of sewing the edges of leaves together to form a place for their tiny nests. The Indian tailorbird is perhaps the best known. When these tiny olive-green and gray birds set about nest building the female punctures the margins of the leaves with her bill. Then she brings cobwebs and pushes them through the punctures in the edges of the leaves, and winds them around, and draws the edges of the leaves together. Strands of cotton are used too for this. Sometimes a single leaf is used; its two edges being drawn together to form a funnel. Sometimes a number of leaves are joined. Sometimes it is claimed knots are used, but this seems not to be the case. What are mistaken for knots seem made in this way: The cotton used is soft and frays easily, so that the part of it forced through a tiny aperture issues as a fluffy knob, which looks like a knot. "The bird makes no knots; she merely forces a portion of the cotton strand through a puncture," and the edges of the puncture catch and hold it, according to Casey Wood, who studied the birds in India. The lining of the nest is of soft material and this the bird anchors by making a puncture in the leaf, grasping a strand of this material, and pulling it out; the cotton outside then expands into a minute button which helps hold the nest and contents in place as though riveted. One nest is recorded as having been so riveted in seventy-five places.

The camouflage of the tailorbirds' nests is very good; it is usually built in thick foliage, the leaves are little deranged, the punctures do not cause the leaf to die; and the leaves being the same as the others, there is little for the eye to pick up as indicating a bird's nest.

SOCIAL PARASITES AMONG BIRDS

The mother who would leave her infant on a stranger's doorstep, to be brought up an orphan, not even knowing its own parents, is a despicable character in human society. But when we leave the man-made society we must leave man-made rules of behavior and man-made prejudices behind. Morals are human. The rest of the animal world is not immoral, it is amoral. It cannot afford criteria beyond survival and reproduction. So while we call certain birds "social parasites," we attach no stigma to them. They represent several groups: the cowbirds, the weavers, the cuckoos, the honey-guides, and the ducks.

Carelessness in egg laying is common even in birds that ordinarily lay their eggs in their own nest and care for them themselves, as for instance the robins' eggs that you may find on your lawn (which of course are wasted; addling and rotting). Perhaps the fate of the eggs of pheasants and ruffed grouse which are found in the same nest may be more happy. Ducks usually make their own nests, but many species occasionally lay eggs in the nest of another species, and one South American duck no longer makes any nest of its own, but is a social parasite, not only on other kinds of ducks, but also on coots and some other birds.

The small, well-marked family of honey-guides of Africa, notable in other ways, also is remarkable for being social parasites. Their favorite host species, chosen to look after the eggs and young, are their close relatives, the barbets (which themselves are most closely related to our woodpeckers).

The nesting of certain African weaverbirds was long a puzzle to ornithologists until it was found they too were social parasites, on other weaverbirds.

VARIED NESTING HABITS The cowbirds, of several species in North and South America, belong to a family notable for the variation in its nesting habits. Their nests vary from the elaborate purse-shaped structures of the oropendola and orioles to the dome-shaped nest on the ground of the meadow lark, the simple cup of the bobolink and redwing; the cowbird makes none. The cowbird lays its eggs in the nests of a wide variety of other species to be cared for by them. Here those who discuss the relative importance of heredity versus environment can profit by considering these social parasites. The young cowbird, hatched and brought up by, say, a yellow warbler, remains a cowbird. As soon as it no longer needs its foster parents' care it flocks with other cowbirds, with all their mannerisms and characteristics, and next season it mates with another cowbird. There is nothing left of its early environment.

The cuckoos of the New World and some of those of the Old make their own nests in normal avian fashion. But a number of Old World species are social parasites, and their behavior has long been a subject of study and discussion. Specializations indicate that here perhaps we have the highest stages of social parasitism. Whereas the cowbird may grow up with nestmates that are the young of the foster parent, unless perchance it crowds them out or starves them if it is larger, the young cuckoo gets the rightful occupants of the nest on its back and throws them out of the nest to perish.

EGGS LOOK ALIKE Another refinement in social parasitism by the European cuckoo is that apparently certain individuals, and apparently certain strains, lay their eggs only in the nests of certain host species. And these cuckoos' eggs resemble those of the particular species in whose nest the cuckoos' eggs are laid. For example, if certain cuckoos lay their eggs only in the nests of meadow pipits these cuckoos' eggs would resemble those of meadow pipits, while another group of cuckoos specializing in hedge-sparrows would have eggs resembling those of hedge-sparrows. Another oriental cuckoo has a color adaptation in the young. In southern Asia these cuckoos parasitize crows, and the nestling cuckoos have black feathers like the young crows; in the Australian area where the same species of cuckoo occurs it parasitizes grayish-brown honey eaters and the young are brown, more like the rightful nestlings. Both these resemblances apparently reduce the chances of the cuckoos' offspring being rejected by the foster parents.

FISH EATS BIRD!

It has become commonplace to hear about birds eating fish. The government gets out reports on the relation of fish-eating birds to fish abundance. The cries of commercial fisheries have caused inquiries to be instituted into the food of cormorants that were supposed to be eating the fish before they grew up enough for us to eat. The scarcity of salmon in some of our Northeastern streams has caused the allocation of biologists to study the predation of kingfisher and merganser on salmon fry and fingerlings.

But fish get some of their own back by eating birds. It's not as spot news as the "man bites dog" angle, but it's certainly less widely known.

To one who has fished for large-mouth black bass among the cypress trees and the bonnets of water hyacinth, and seen the bass strike savagely at surface lures as soon as they hit the surface, it comes as no surprise to find they strike at, and catch, such birds as Maryland yellow-throats that flutter across close to the surface of the water.

Young ducks, too, are good game to the large-mouth, and probably many a young duck finds its way into the maw of a bass. On a pond where bass had taken many young ducks I heard a story of a fisherman who made a floating model of a mother duck, powered it with a propeller, and attached to it by lines of various lengths several floating models of downy ducklings. In each duckling was concealed a hook. The whole flotilla was set afloat, and drifted across the pond. Mother steamed ahead, with young following. Soon the bass, used to a duck diet, began to grab the ducklings. When the model was retrieved several large bass were taken.

In Northern waters, where Northern pike, or jackfish, as they're called in the North, abound in duck-nesting waters, pike are accused of eating enough ducklings to affect the survival of the broods. Many a marshland traveler has reported young ducks and young grebes diving, to be seen no more. He's blamed the pike. Sometimes perhaps the young bird has simply come up unobserved. But enough pike's stomachs have proved to have young ducks in them to demonstrate pike do eat ducklings. Strangely, in some areas, pike eat many ducklings; in others they do not eat them. But it's not alone young birds or small birds that get eaten by fish.

A twenty-four-inch bass is recorded as having been caught while it still had the legs of a full-grown coot projecting from its mouth. From beak to tip of its outstretched legs the coot measured seventeen inches and it weighed one and one quarter pounds.

Angler fish weighing between forty and fifty pounds have been found to have eaten birds. One had the band from a Manx shearwater in its stomach, and another had an adult American merganser. In tropical and subtropical seas the examination of birds seemed to indicate they had been attacked by some fish and seized by the feet, but were able to escape, and a white-winged black tern off Corsica has been seen to disappear under the water, presumably dragged under by a fish.

CROWS ARE SMARTER THAN "WISE" OWLS

The owl has always been considered the symbol of wisdom. The old saying has it that "fine feathers don't make fine birds," but I'm afraid that the owl has taken in people with its appearance. The owl's reputation for wisdom seems to be based on a staid, impressive appearance combined with an inarticulate disposition. Though owls do at times make a great deal of noise, hooting, shrieking, and whistling, much of the time the owl sits quietly looking wise and saying nothing. But owls don't seem to have much behind the front they put up. People who have studied them find the young are very slow to learn to feed themselves, and one saw-whet owl that was kept captive refused to eat liver put into its cage, apparently not recognizing the meat as food. But when the liver was stuffed into an empty mouse skin the owl at once ate it. One might conclude that the owl was the original "stuffed shirt."

The crows and their relative, the jays, are the birds that are really intelligent. They are active and usually have little trouble getting enough to eat. They have an abounding curiosity that leads them to spend their time investigating things and getting new experiences. And they seem to profit by these experiences, too.

The following is how three ravens co-operated in getting a bone from a dog, as written by B. J. Bretherton:

"He was espied by a raven who flew down and tried to scare the dog by loud cawing, in which he was shortly afterwards assisted by another, both birds sidling up to the dogs head until they were barely out of his reach. Just at this time a third raven appeared on the scene and surveyed the situation from an adjacent fence, but soon flew down behind the dog and advanced until within reach of his tail, which he seized so roughly that the dog turned for an instant to snap at him, and at the same moment the bone was snatched away by one of the ravens at his head."