That is the way some birds manage to put on their spring dress in the fall. The solid color is the color of the spring, but it is hidden or veiled by tips of another color for winter.
The meadowlark changes in this way. In the winter his coat is brownish, or buff. In the spring these tips are worn or broken off, and he comes out in yellow and black.
Another change, even more curious, is made by some birds, who all winter wear white spots, or light scolloped edges to their feathers, and in spring the spots are gone.
In these, the white or light parts only break off, as sharply as if cut with scissors. They leave the edges of the feathers notched in queer ways, but as they lie over each other that does not show.
[Ill.u.s.tration: BLACK AND WHITE WARBLERS (MALE AND FEMALE)]
Birds in this way can change color without changing their feathers.
While moulting but once a year, they can show two suits, and by partially moulting twice, can show three suits.
Another thing about the color of feathers is interesting. Some colors, such as black, and red, and brown, are caused by coloring matter in the feather. But other colors are only an effect of the way the feather is made, whether it has ridges on it, or certain minute specks under the surface, which seem to act as prisms (says Dr. Newton), and reflect the light in different colors.
For instance, green is always due to some shade of yellow coloring matter under a surface full of lengthwise ridges, and other colors are made in similar ways.
These curious facts have been found out by that tell-tale little instrument the microscope, and no doubt it will reveal many more secrets in time.
Color is useful to birds, as well as beautiful. Its great use is to conceal them from their enemies, and they show that they know this by their conduct.
When a bird is of the color of dead leaves, or the sand, he has only to flatten himself and keep still, and he is hidden. Such a bird on the nest will often let one come close, and even stroke her, while relying on her color to be unseen. A sitting ruffed grouse will do so. But if snow falls, the same bird is very wild, for she knows she can be seen in the snow.
I have seen a striped bird,--black and white warbler,--when frightened, flatten himself on a branch, where he looked so much like the bark that he could not be seen.
Ground birds are mostly in mottled colors of the ground. The whip-poor-will, whose habit it is to rest on a log all day, wears colors that hide him as well as if he were under the log.
The striking colors on a bird are often bidden when he is at rest, but show plainly when he flies. When a flicker stands quietly on a fence he is all in rather dull colors, but when he flies he shows a large snow-white spot on his back, so that as far as one can see him he may be known.
A meadowlark on the ground looks not unlike a flicker, but when he flies he shows that the outside feathers of his tail are white. This is as striking a mark as the white spot on the flicker.
Many birds have such markings, and it is thought by men who study birds and look for a use in everything, that such marks serve the purpose of "danger signals" or "recognition marks." That by these birds can know each other in the dusk, or that the flash of color will catch the eye, when the bird does not wish to give a call, but to slip away quietly to avoid danger, and at the same time to give notice to other birds to do the same.
HIS RELATIONS WITH US
XXVIII
HOW HE WORKS FOR US
MANY times in this book I have spoken of the great value of the services of birds, in helping us destroy insects and weeds that injure our crops.
But there is more to be said about it.
From morning till night, almost the whole of his life, nearly every bird is working for us. He does not know he is working for us, of course. He is simply hunting for the food he likes, and what is good for young birds to eat.
But what he chooses to eat himself, and to feed the young, consists mostly of creatures that destroy our fruit and vegetables, caterpillars that eat the leaves off our trees, worms that get into our apples and berries, beetles that spoil our roses and our potatoes, mice that eat our crops, and all the worms and grubs that gardeners and farmers are all the time fighting.
As I have already said, some of the birds like cherries and green peas, and other things we prefer to keep for ourselves. But we should never forget that they have earned, by their work among the worms, all they can take.
[Ill.u.s.tration: CEDAR-BIRD]
I say this, not merely because I love the birds, and want to have them live and be happy, but because it is true. It has been proved true by scientific men in the service of the United States government.
These men have had thousands of birds killed to see what they were eating, and have found out that nearly all the birds they have examined--blackbirds, cedar-birds, blue jays, hawks, owls, even crows--do us more good by the injurious creatures they destroy, than harm by the fruits and vegetables they eat. To this there is, among the small birds, but one exception, the English sparrow, and, of the large ones, only the two hawks and one owl, mentioned on page 53.
Chickadees like to eat the eggs of cankerworms; and for a single meal, one of these tiny birds will eat two hundred and fifty eggs, and he will take several meals a day. Now cankerworms destroy our apples. When they get into an orchard in force, it looks, as Miss Merriam says, as if it had been burned over.
Robins, catbirds, and shrikes, and several others, like to eat cutworms, which destroy gra.s.s and other plants. As many as three hundred of them have been found in the stomach of one robin, of course for one meal.
Ants are very troublesome in many ways, and three thousand of them have been taken from the stomach of one flicker.
Rats and mice, ground squirrels and gophers, make great havoc in our crops, and farmers spend much time and labor trying to get rid of them; but these creatures are the favorite food of most hawks and owls.
If the farmer would stop shooting the birds, and protect them instead, they would do this work for him, and much better than he can. But because (as I said in a former chapter) one or two hawks and owls have a taste for chickens, he generally kills every hawk and owl he sees, and for this folly has to spend half his time trying to kill the little animals they would gladly have eaten.
A great deal of refuse, dead sea creatures, and other matter, is thrown up on the seash.o.r.e, or floats on the water. On this feed the water birds,--herons, gulls, terns, and others. If this were not disposed of, it would make us sick. Indeed, on the sh.o.r.es where so many herons have been killed, to get their plumes for ladies" hats, the result has been sickness and death among the people, as Dr. Gaumer, of Yucatan, told Mr.
Chapman.
Besides the work they do for us in destroying animal life, their seed-eating is almost as useful. As I said, they eat the seeds of weeds that farmers and gardeners are all the time laboring to keep down, so that useful plants may have a chance to grow.
The whole family of finches, sparrows, buntings, grosbeaks, and all birds with the high, thick bill, though they eat largely of insects through the summer, and feed their nestlings on them, when insects get scarce and weed seeds are ripe, turn to the latter for food. They eat the seeds of all kinds of troublesome weeds; and as each single seed might produce a plant, we cannot guess how much they destroy.
Professor Beal, who is at the head of this government inquiry into the food of birds, and who knows what he is talking about, says that one species of little bird--the tree sparrow--destroys every year in one of the Western States, many tons of the seeds of weeds.
There is a curious and interesting fact about this seed-eating. The regular seed-eaters, the finches, prefer the seeds of certain weeds, most of them harmful; these they break up, taking off the sh.e.l.ls, and of course destroying the germ, making it impossible for them to grow.
But there are many birds who eat berries having in them seeds, such as raspberries, blackberries, and all kinds of wild fruit. These birds do not crack the seeds; and, as they are hard, they do not digest in the stomach, but are dropped whole, and are ready to grow wherever they fall.
Thus, while seed-eating birds destroy the weeds which are hurtful, the fruit-eaters plant the seeds of berries and fruit which we like. That is why we find wild berry bushes all over the country. We have to thank the birds for it.
A great deal more could be said about the birds" work for us, not only of the robins and those I have spoken of, but cedar-birds, who are shot because they take part of our cherries, blackbirds, because they eat some grain, orioles, because they occasionally take green peas, and kingbirds, because they have the name of eating bees, though it has been proved that they eat only drones, which have no sting and make no honey.
Let me impress upon you two facts. First, the stories of the harm done by birds are often mere guesswork, from careless observation. For instance, a man seeing a bird going over his blossoming fruit-trees, at once concludes he is destroying the fruit, probably shoots him, and then writes to his favorite paper that a certain bird eats fruit buds. Other papers copy it, and a war against that bird begins in every orchard.
Whereas, the truth is, the bird was preserving the fruit by picking out the insects that would have spoiled it. This is no fancy picture; this very thing has happened more than once.
And again, whatever is said about the harm this or that bird does, never forget this second fact, which I repeat, and which may be relied upon as perfectly trustworthy. The officers of the government of the United States, who have carefully studied the matter and found out positively, without guesswork, what birds eat, have declared emphatically that every bird they have examined does more good by destroying pests, than harm to our crops, excepting only the bird we have imported,--the English or house sparrow.
XXIX