Part 10

To care for the weak, the unfit, and the cripple is usually considered an extremely highly developed altruism in our society. As our society progresses, more and more provisions are made for the unfit.

In nature the unfit usually is soon weeded out. If an animal is unable to feed itself it is doomed; or if it is less successful than its fellows it has less chance of leaving progeny. That is natural selection.

Hence on both counts it comes as a surprise to find two well-authenticated cases of crippled birds, unable to search for food for themselves, surviving for long periods.

The first is T. R. Peale's record in 1848 of a brown booby on Enderby Island in the Pacific. An adult bird whose plumage indicated it was several years old was found on the island, and it had only one wing, the other having been lost by some accident and the wound completely healed. The bird was unable to go to sea and get its own food, and was being fed by its fellows.

The second was a frigate bird, found on the Revillagigedo Islands, reported by A. W. Anthony in 1898. This bird, too, was fat, and had one wing withered and useless, evidently from hatching. It had never flown. Frigate birds are masters of the air that snatch their food on the wing from the surface of the water, and a flightless frigate bird would be as badly off as a flightless swallow. The cripple had been fed all its life by its neighbors.

At first the uncritical might think, What altruism, what charity, for the healthy to feed these two cripples. But an explanation involving less advanced principles, principles more in keeping with what we know about bird behavior, is possible. Remember that young birds that are unable to begin feeding themselves at the proper time may continue to beg for food, and be dependent for a long time, as I have shown with young shrikes under the chapter, "Conditioning in Birds." Remember that a young bird begging for food may be fed by adults, not its parents, and even by other young birds (shown in "Bird Helpers at Nesting Time"); and we have the clue.

The cripples, hungry, begged for food; the healthy birds responded by feeding, as they might do to other begging young, and owing to the unusual circumstances both were continued.

These certainly are cases where the unfit survived. Natural selection has not operated. But such cases are rare exceptions.

DUST AND SNOW BATHING

The taxidermist preparing a bird specimen for the museum sometimes has to deal with one whose plumage is soiled or stained. He may have to wash it with water. Then, to dry the plumage, fluff it, and help in arranging the plumage so it will lie smooth and natural, he may use a powder: corn meal, sawdust, plaster, or plaster and potato starch may be worked into the feathers, then dusted out again. It is interesting that birds themselves use and have used long before taxidermists a similar method of using dust in dressing their feathers, a fact that anyone who has watched domestic hens for any length of time must be aware.

A DIRTY BATH Recently I watched a house sparrow dusting by the railway track in the city of Chicago. The dust may have been in part "clean" earth, but in part it was soot, city dust, and soft-coal debris. The sparrows here were dingy, all had their plumage heavily impregnated with city grime, and looked very different from the sparrows in the country. And this sparrow I was watching when it had finished dusting was the worst of the lot. These city sparrows, even when they bathe in water, seem never to get much of the grime out of their feathers.

This reminded me that Oscar Heinroth once wrote that birds do not bathe to get themselves clean, but bathe as an aid in bringing their feathers into order and making them lie smoothly. Perhaps he is right. Certainly my sparrow did nothing to clean himself.

It is in arid countries, plains and deserts especially, where many of the birds take only dust baths. In more humid regions water bathing is the rule. But some birds do both, like our flicker and our house sparrow, bathing now in water, now in sand.

In northern climates, when the land is held in the grip of winter, the water frozen over, and the earth covered with snow, neither dust nor water bathing is possible. Then, it has been recorded, some birds find a substitute in snow. Among other cases, in Alaska the hawk owl has been seen to perch in the snow on the tops of telephone poles, and go through the motions of bathing; in England a rook was recorded as bathing "in crisp powdery snow as if it were taking a bath in dust or water"; and in New England in midwinter juncos have been recorded bathing "in light dry snow, just as other sparrows take dust baths in hot weather."

The snow evidently is used as a substitute for dust in these northern latitudes.

DECORATION IN THE HOME

To use a bunch of flowers or a spray of leaves in decorating a room in a house is a refinement of civilization. As the flowers fade, or the leaves wilt, they are replaced with fresh ones. Sometimes a winter bouquet is used that will serve for months.

There are several birds that habitually deck their nests with green vegetation, and when it is wilted, it is renewed with fresh. The reason is not clear. It has been suggested it is to supply humidity and, by evaporation, coolness; it has also been suggested that its use serves a sanitary purpose. But whatever the reason in birds' eyes, it looks like decoration to human eyes.

This habit is common with a number of different hawks: for example, the red-tailed hawk is reported sometimes to have its nest, a bulky flat, basin-shaped structure in the crotch of a tree, "profusely and beautifully lined with fresh green sprigs of white pine, which are frequently renewed during incubation and during the earlier stages in the growth of the young." The golden eagle is said to add green grass, or green leaves often attached to the twigs from time to time to the lining of the nest, especially after the young are hatched; and the broad-winged hawk is said to add green leaves to the lining of its nest. In quite another group of birds the same thing also occurs. A carrion crow's nest in England was visited periodically from March to August. Strangely no eggs were laid during this whole period, but the birds remained in attendance. When found, fresh sprigs of oak leaves were interwoven around the rim of the nest. On subsequent visits the oak leaves were found to have been replaced with fresh ones, and the leaves were kept fresh until late August.

The purple martin supplies another example. The nest boxes we put up for them supply their main breeding places in some areas. "The parents have a habit of collecting many green leaves and placing them in the nest, a practice which may tend by evaporation to reduce the heat" in the next box. "Where large colonies are breeding they sometimes injure pear trees by stripping certain branches of their leaves," according to E. H. Forbush.

A Madagascar weaverbird provides an example of decorating the nest entrance of a quite different type of nest; in this case the nest is in the shape of an inverted retort, with the entrance through the spout. The entrance is decorated with green grass heads or with green leaves, and the males keep adding fresh green decorations even when the eggs are being incubated by the female.

It seems hard to believe that this is really decoration, that it is not for some purpose--either connected with the raising of the young, or more probably a leisure or substitute activity--something to keep the bird busy and strengthen the bond between bird and nest when it is not otherwise directly occupied with nesting activities.

CURIOSITY IN BIRDS

Being unable to ask birds questions that will receive answers, we have to judge their motives from appearances. And from the way some birds act curiosity seems a strong motivation at times. They show a disposition to inquire into things, especially strange things.

Young blue jays that I've raised and studied are among the most prying, investigating, inquisitive birds I've known. When well fed they devoted much time to examining things. Humans, of course, would examine objects by picking them up in their hands, looking at and feeling them, perhaps tasting them. The jays, with more limited equipment, would examine them with bill and eye. When the jays were very young their toes interested them. They pecked at and twisted their own and their neighbor's toes. Pencils and crayons on my desk appeared to interest them particularly. These they were continually pulling about and pecking at. They went about picking at lines on paper, knotholes in the walls of their cage, the red letters printed on a bottle label, and the buttons on our clothes. Cigarettes they liked to investigate by pulling them to pieces. It looked as if the jays were interested in finding out about the things around them by touch and taste as much as they could.

LURED INTO DANGER Compared with jays, ducks seem rather stolid creatures, but they have curiosity too. This was well known to the old-time duck hunters who capitalized on it in duck shooting. The technique is known as "tolling" and I've used two variations of it in museum collecting.

Once on a little mountain lake in New Guinea I found a pair of ducks of a rare species I especially needed for our collection. I stalked them to the farthest bit of cover I could reach, a tussock of grass on the lake margin, behind which I lay concealed. But the ducks were still too far away for me to reach, and their feeding did not seem to be drawing them nearer. I remembered the gunners' trick of tolling, and tried it. I took out my white handkerchief, held it above the tussock of grass while I kept well hidden, and waved the handkerchief back and forth. The response was surprisingly prompt and gratifying. The two ducks turned at once and swam right in to me so that I secured them without any trouble.

Once on a lake in central New York State there was a flock of scaup ducks swimming well offshore. It looked as if they never would come in near the bank. Quite by accident a setter dog that accompanied us began to cavort along the beach. Again the ducks turned and the whole flock came swimming in. Only then did I remember that among old-time gunners there was the practice of using a dog thus, a dog that was even trained for the purpose, to jump high and run about very conspicuously while the ducks were far out, and as the ducks came swimming in, to keep lower and frisk about partly concealed so that the ducks would have to come close to satisfy their curiosity.

REFERENCES

Is it true? Did it really happen? The implications and correlations are my own, and some of the accounts on the previous pages are based on my experiences. But many of the facts come from the writings of others. Where the incidents are well known no documentation is given. But when the behavior described is little known or only recently discovered I've given a reference so that the source can be consulted. These are arranged under the appropriate chapter headings.

BIRDS USING TOOLS

Edna Fisher, _Jour. Mammalogy_, Vol. 20, p. 21 (sea otter). P. A. Gilbert, 1939, _Emu_, Vol. 39, pp. 18-22 (satin bower bird). D. Lack, 1947, _Darwin's Finches_, p. 59 (woodpecker finch). D. Morris, 1954, _British Birds_, Vol. 47, p. 33 (song thrush). A. C. Bent, 1921, _U. S. Natl. Mus. Bull._ 113, p. 111 (gull and crow).

BIRDS AS BRIGANDS

A. L. Rand, 1954, _Fieldiana-Zoology_ (Chicago), Vol. 36, p. 35 (eagle, skua, frigate bird).

BIRDS BATHING

F. N. Bassett, 1922, _Condor_, Vol. 24, p. 63 (hummingbirds). A. C. Bent, 1937, _U. S. Natl. Mus. Bull._, 167, p. 370 (osprey).

HOW BIRDS ANOINT THEIR FEATHERS

W. L. McAtee, 1938, _Auk_, Vol. 55, p. 98 (review).

TRAVELING BIRDS' NESTS

H. S. Swarth, 1935, _Condor_, Vol. 37, p. 84 (barn swallows). M. A. Common, 1942, _Auk_, Vol. 59, p. 43 (tree swallow). D. L. Serventy and H. M. Whittell, 1948, _Birds of Western Australia_, p. 243 (welcome swallow).

MALADAPTATION IN BIRDS

J. Grinnell, 1926, _Condor_, Vol. 28, p. 97 (robin). W. H. Bergtold, 1930, _Auk_, Vol. 47, p. 571 (robin). H. W. Henshaw, 1921, _Condor_, Vol. 23, p. 109 (California woodpecker). D. Bannerman, 1933, _Birds Tropical West Africa_, Vol. 3, p. 415 (thick-billed honey-guide).

FEATHERED BABY SITTERS AND CO-OP NURSERY NESTS

D. Davis, 1940, _Auk_, Vol. 57, p. 179 (ani). A. C. Bent, 1925, _U. S. Natl. Mus. Bull._, 130, p. 85 (eider duck). R. C. Murphy, 1936, _Oceanic Birds of South America_, Vol. 1, p. 398 (penguins).

BIRDS' NESTS AND THEIR SOUP

Gibson-Hill, 1948, _Malay. Nat. Jour._, Vol. 3, p. 190; F. H. Giles, 1935, _Jour. Siam Soc. Nat. Hist. Suppl._, Vol. 10, p. 137; and Jabouille, 1931, _L'Oiseau et Rev. Franc. d'Ornith._, Vol. 1, n.s., p. 219 (swiftlets).

WALLED WIVES OF HORNBILLS

R. E. Moreau, 1937, _Proc. Zool. Soc._ London, 1937, p. 331 (hornbills).

BURIED EGGS AND YOUNG

A. Newton, 1893, _Dictionary of Birds_, p. 733; and D. Bannerman, 1931, _Birds Trop. West Africa_, Vol. II, p. 205 (crocodile bird). Deusing, 1939, _Auk_, Vol. 56, p. 367 (grebe). Bent, 1925, _U. S. Natl. Mus. Bull._, 130, p. 98 (eider duck).

THE SNOWY OWL AS A TRADE INDEX

A. Gavin, 1947, _Wilson Bull._, Vol. 59, p. 202 (snowy owl).

MONKEY BIRDS

A. L. Rand, 1954, _Fieldiana-Zoology_ (Chicago), Vol. 36, p. 23 (various "monkey-birds").

BIRD-MADE INCUBATORS

C. G. Sibley, 1946, _Condor_, Vol. 48, p. 92; Coles, 1937, _Proc. Zool. Soc. London_, 1937, pp. 261-73; Fleay, 1937, _Emu_, Vol. 36, pp. 153-63 (mound builders).

CORMORANT FISHING

B. Laufer, 1931, _Publ. Field Mus. Nat. Hist. (Anthr. Ser.)_, 18, pp. 201-62; Gudger, 1926, Amer. Nat., 60, p. 5 (cormorant fishing).

THE SHRIKE'S LARDER

A. C. Bent, 1950, _U. S. Natl. Mus. Bull._ 197, p. 120 (shrike's larder).

BIRD FLAVORS

H. B. Cott, 1946, _Proc. Zool. Soc. London_, Vol. 116, pp. 371-524 (bird flavors).

HOW MANY FEATHERS HAS A BIRD?

A. Wetmore, 1936, _Auk_, Vol. 53, p. 159; F. B. Hutt and L. Ball, 1938, _Auk_, 55, p. 651 (number of feathers).

LAST YEAR'S BIRDS' NESTS

A. C. Bent, 1925, _U. S. Natl. Mus. Bull._ 130, pp. 91, 92; H. F. Lewis, 1938, _Bird-Lore_, Vol. 40, p. 239 (eider down).

SYMBIOSIS--ANIMALS LIVING IN MIXED HOUSEHOLDS

A. C. Bent, 1938, _U. S. Natl. Mus. Bull._ 170, pp. 384-86, 398 (burrowing owl). H. Friedmann, 1930, _Natural History_, Vol. 30, p. 205 (social weaver). W. H. Hudson, 1920, _Birds of La Plata_, Vol. 2, p. 31 (monk parrot). W. R. B. Oliver, 1930, New Zealand Birds, p. 118 (_Sphenodon_).

BIRD APARTMENT HOUSES

A. C. Bent, 1942, _U. S. Natl. Mus. Bull._ 179, p. 490 (purple martin). A. Wetmore and F. C. Lincoln, 1933, _Proc. U. S. Nat. Mus._, Vol. 82, art. 25, p. 44 (West Indian woodpecker). D. Bannerman, 1933, _Birds of Tropical West Africa_, Vol. 3, p. 381 (barbets). J. T. Emlen, 1954, _Auk_, Vol. 71, p. 16 (cliff swallows). W. H. Hudson, 1920, _Birds of La Plata_, Vol. 2, p. 31 (monk parrot). A. Wetmore and B. H. Swales, _U. S. Natl. Mus. Bull._ 155, p. 346 (palm chat); H. Friedmann, 1930, _Nat. Hist._, Vol. 30, p. 205 (social weaver).

BIRD HELPERS AT NESTING TIME

A. Skutch, 1935, _Auk_, 52, p. 257 (helpers at nest). M. M. Nice, 1943, _Trans. Linn. Soc._, Vol. 6, p. 79 (young feeding young). R. C. Murphy, 1936, _Oceanic Birds of South America_, Vol. 1, p. 360 (emperor penguins).

WEAVERS AND TAILORS IN THE BIRD WORLD

H. Friedmann, 1922, _Zoologica_, Vol. 2, p. 355 (weaverbird). C. A. Wood, 1926, _Smithsonian Rept._, p. 349 (tailorbird).

SOCIAL PARASITES AMONG BIRDS

A. H. Miller, 1946, _Sci. Monthly_, Vol. 62, p. 238 (social parasites).

FISH EATS BIRD!

W. E. Glegg, 1945, _Ibis_, p. 422 (fish eating birds).

CROWS ARE SMARTER THAN "WISE" OWLS

A. L. Rand, 1943, _Canad. Field Nat._, Vol. 57, p. 35 (saw-whet owl). A. L. Rand, 1942, _Bull. Amer. Mus. Nat. Hist._, 79, p. 518 (blue jay). A. C. Bent, 1946, _U. S. Natl. Mus. Bull._ 191, p. 196 (raven), p. 266 (crow).

TAME WILD BIRDS

D. Lack, 1942, _Ibis_, p. 271 (flycatcher). A. H. Chisholm, 1943, _Ibis_, p. 105 (honey eaters). H. H. Brimley, 1934, _Auk_, 51, p. 237 (phoebe).

BIRDS AS PILFERERS

A. L. Rand, 1954, _Fieldiana-Zoology_, Vol. 36, p. 31 (pilfering, several species).

HIBERNATION IN BIRDS

W. L. McAtee, 1947, _Amer. Midland. Nat._, 38, p. 191 (old records on torpidity). E. C. Jaeger, 1949, _Condor_, 51, p. 105 (poor-will).

SNAKESKINS IN BIRDS' NESTS

A. L. Rand, 1953, _Nat. Hist. Miscl._ (Chicago), No. 125 (snakeskins in nests).

CO-OPERATION BY BIRDS

A. L. Rand, 1954, _Fieldiana-Zool._ (Chicago), Vol. 36, pp. 10, 12 (co-operation, various species).

WATCHDOGS AT THE NEST

R. E. Moreau, 1942, _Ibis_, p. 240 (in Africa). D. R. Dickey and A. J. van Rossem, 1938, _Publ. Field Mus. Nat. Hist._, _Zool. Ser._, Vol. 23, p. 360 (in El Salvador).

BIRD GUIDES TO HONEY

H. Friedmann, 1954, _Nat. Geog. Mag._, Vol. 105, p. 551 (honey-guides).

OXPECKERS

D. Bannerman, 1948, _Birds of Tropical West Africa_, Vol. 6, p. 105 (oxpecker).

WINGS IN FEEDING

J. Delacour, 1946, _Auk_, Vol. 63, p. 441 (black heron).

CONDITIONING IN BIRDS

A. L. Rand, 1942, _Bull. Amer. Mus. Nat. Hist._, Vol. 79, p. 517 (shrikes).

POISONOUS BIRDS

E. H. Forbush, 1927, _Birds of Mass._, etc., Vol. 2, p. 34 (ruffed grouse). D. L. Serventy and H. M. Whittell, 1948, _Birds of Western Australia_, pp. 73, 74 (Australian pigeons). R. Meinertzhagen, 1912, _Ibis_, p. 96 (Mauritius pigeon).

BIRDS WASHING FOOD

F. G. Evenden, 1943, _Condor_, 45, p. 120 (dipper). For divers records of washing food see _British Birds_ for 1946, 6 and 8.

HOW BIRDS USE COWS AS HUNTING DOGS

A. L. Rand, 1953, _Auk_, 70, p. 26 (ani).

BATTLE OF THE SEXES AND ITS EVOLUTIONARY SIGNIFICANCE

A. L. Rand, 1952, _Fieldiana-Zoology_ (Chicago), Vol. 34, p. 65.

WATER IN THE DESERT

C. T. Vorhies, 1945, _Univ. Ariz. Agri. Exp. Sta. Tech. Bull._ 107 (water need in desert). J. T. Emlen, Jr., and B. Blading, 1945, _Univ. Calif. Coll. Agri. Bull._ 695, p. 34 (valley quail). E. G. B. Meade-Waldo, 1922, _Bull. Brit. Orn. Cl._, Vol. 42, p. 69 (sand grouse).

BIRD GRAVEYARDS

R. C. Murphy, 1936, _Oceanic Birds of South America_, Vol. 1, p. 372 (penguins). U. M. Grigg, 1950, Brit. Birds, Vol. 43, pp. 11-13 (graveyard in hollow tree). G. Simmons, 1927, _Nat. Geog. Mag._, Vol. 52, p. 27 (petrel bones on Cima).

ANIMAL GARDENS

R. C. Murphy, 1936, _Oceanic Birds of South America_, Vol. 1, p. 374 (penguins). F. Harper, 1953, _Amer. Midland Nat._, Vol. 49, p. 6 (birds and lichens). H. W. Feilden, 1877, _Zoologist_, Vol. 1, p. 319 (arctic-fox gardens).

DROPPING THINGS

M. E. W. North, 1948, _Ibis_, p. 138-41 (lammergeier). E. Jaeger, 1951, _Condor_, 53, p. 207 (sparrow).

LEARNING BY BIRDS

A. L. Rand, 1941, _Bull. Amer. Mus. Nat. Hist._, Vol. 78, p. 222 (thrasher). A. L. Rand, 1942, _Bull. Amer. Mus. Nat. Hist._, Vol. 79, p. 518 (blue jay).

CAN BIRDS COUNT?

_Bird-banding_, 1940, Vol. 11, p. 121 (summary various experiments).

COURTSHIP FEEDING

D. Lack, 1940, _Auk_, Vol. 57, p. 169 (courtship feeding).

THEY TURNED THE TABLES

A. C. Bent, 1926, _U. S. Natl. Mus. Bull._ 135, p. 109 (great blue heron). W. P. Baldwin, 1946, _Auk_, Vol. 63, p. 589 (oyster catcher). G. Mackay, 1929, _Auk_, 46, p. 123 (goldfinch). D. Bannerman, 1936, _Birds Tropical West Africa_, Vol. 4, p. 244 (dusky flycatcher).

SURVIVAL OF THE UNFIT

A. W. Anthony, 1898, _Auk_, Vol. 15, p. 314 (frigate bird). J. Cassin, 1858, _United States exploring expedition ..., Mammals and Birds_, Philadelphia, p. 364 (brown booby).

DECORATION IN THE HOME

A. C. Bent, 1937, _U. S. Nat. Mus. Bull._ 167, p. 151 (red-tailed hawk), p. 296 (golden eagle). M. R. Lieff and N. P. Jordan, 1950, _British Birds_, Vol. 43, p. 56 (carrion crow). E. H. Forbush, 1929, _Birds of Mass., etc._, Vol. 3, p. 141 (purple martin). A. L. Rand, 1936, _Bull. Amer. Mus. Nat. Hist._, Vol. 72, pp. 487, 490 (weaverbird).

INDEX

adaptation, 31 Aeschylus, death of, 186 Aeschylus on vultures, 172 ani, feeding rates of, 168 anointing feathers, 25 anting, 27 anvil, thrush's, 15 apartment houses, 77 Arctic fox and snowy owl, 49 association of: burrowing owl, prairie dog, snake, 73 lizard, petrel, 75 parrot, duck, opossum, 75 social weaver, falcon, 74

baby sitters, 35 bad and good birds, 152 bathing in dust, 204 bathing in snow, 204 bathing in water, 22, 205 beehives, guiding to, 125 beeswax as bird food, 125 bird of paradise, 162 boat names, 84 booming of nighthawk, 135 bower, painting of, 16 brigands, birds as, 19 brush turkey, 54 bucket drawing by jay, 190 buried eggs, 45 buried young, 45

cassowaries swim, 149 cattle disease and oxpeckers, 129 _Chicago Tribune_ farm, 151 cliff dwellers, 78 colony, mixed, 73 colony nesters, 77 color, change in jay, 164 color and palatability, 63 communistic care of young, 37 community nests, 35 conditioning, 136 conservation, 151 co-operation, 117 co-operation: birds and monkeys, 51-53 cow and ani, 167 in carrying prey, 118 in fishing by pelican, 118 in killing skunk, 119 co-op nursery, 35 cormorant: fishing with, 57 training, 58 cosmetics, various, 26 counting, of photographers, 193 distinguishing more from less, 193 courtship feeding, 195 function of, 197 significance of, 195 covering eggs: by eider duck, 47 by grebe, 47 cows, use as hunting dogs, 167 credit and snowy owl, 48 cripples, cared for, 201 crocodile bird, 45 crow, intelligence of, 98 crows profit by experience, 99 curiosity, 210

dangerous prey, 198 death: caused by clam, 199 by porcupine, 202 by spiders, 200 decoration: function of, 209 in nests, 207 snakeskin in, 113 droppings things: 186 by crows, 16 by gulls, 16, 187 by lammergeier, 186 by sparrow, 187 reason for, 188 drumming: of grouse, 134 of woodpecker, 133 drunkenness, 32 duck, muscovy, 162

ecological competition, 173 eggs: buried, 55 covered, 46, 47 in other birds' nests, 91 specializations, 93 eider down, 71 environment modifies heredity, 139 Eskimo, credit to, 48 experience: crows profit by, 99 learning by, 189

feathers: and size of bird, 67 and temperature, 67 number of, 66 feeding rates of ani, 168 fish eats bird, 95 fishing with cormorants, 57 flavor of flesh, 63, 142 flesh: flavor of, 63, 142 poisonous, 141 fluctuations in the Arctic, 48 food: impaling of by shrike, 61 storage of, 32, 61 foster parents, 93 foster young, specialization in, 93 foxing, 166 frogs mistaken for birds, 109

gardens: animal, 183 ecological balance in, 153 of Arctic fox, 185 good and bad birds, 152 grackles, character of, 152 graveyards: 180 in hollow tree, 181 on island, 182 penguins', 180 green hunting jay, 164 guarding birds' nests, by insects, 121 guides to honey, 124

hair pulling, 102 helpers at nesting time, 81 heredity modified by environment, 139 hibernation, 108 honey guides: 124 lead to big game, 125 hornbills' nests, 42 households, mixed, 73

identification: caution in making, 161 errors in, 161 over the telephone, 160 sight, 161 incubation, artificial, 56 incubators, bird-made, 54 infantile behavior modified, 137 inquisitive birds, 210 instrumental music, 133 intelligence, comparative, 98 intoxication, 32

jays: change of color in, 164 helping at nest, 81

kingfisher: a painting of, 143 classical allusions to, 145 on the telephone, 143 variation in, 144