The Animal World, A Book of Natural History Part 60

There is the singer--half a dozen of them in fact--fluffy little gray, black-capped birds not much bigger than a man's thumb, dodging busily about the limbs of that old apple-tree, swinging with desperate clutch at the tip of a twig, hanging head downward to get at a morsel on the under side of the bough, and chattering all the time as though cold weather were no hards.h.i.+p at all.

What do they find to eat? Keep your eyes on one, and see if you cannot guess. He is pecking here and there at the bark, and swallowing something so minute we cannot recognize it. But do you not remember how, last summer, we watched the procession of ants climbing this very tree to get honey from a "herd" of aphids on the branches? Those bark-lice are still there, each hidden under a sort of scale, like a winter blanket; and it is these that the chickadees are pulling off and eating.

It takes a great many of them to make a meal, and the birds must keep very busy. Perhaps that is one reason why they seem so happy. A busy person is usually a cheerful one.

When you meet a winter group of these merry tomt.i.ts it is well to wait quietly for a little while, since you are pretty sure to find others following them. There! do you hear that sharp tapping? Turn your head and you will see a small woodp.e.c.k.e.r with its checkered black and white coat, and a broad white stripe down the back, hewing away at the thick bark of that oak. He is tremendously in earnest, and let us hope he finds a good fat grub.

Gliding down the next tree-trunk comes something which for an instant we take for a mouse--it is so bluish and furtive; but it is a bird--a nuthatch--which has a straight slender bill almost like a woodp.e.c.k.e.r's, and which digs into the cracks and crannies for eggs and hiding grubs of small insects, now and then smas.h.i.+ng a thin-sh.e.l.led acorn for the wormy meal it contains, or tearing to pieces the fuzzy coc.o.o.n of a tussock-moth. It has an odd habit of working almost always head downward, and now and then lifts its head and squeaks out a sharp _nee-nee-nee_, as though it said "Never-mind-me. 'Tain't cold!"

Quite likely on the next tree a brown creeper--sedate brown little lady of a bird--is gliding about the trunk, very daintily picking and searching with her long slender and curving beak for similar hidden food. She is a dear little creature.

Even prettier are the kinglets that often form one of this little company of winter workers. They are the smallest of all American birds except the hummers, and are olive green with tiny crowns of gold and rubies, as one might say. They have the activity and nimbleness of the chickadees, and toward spring cheer us with a brilliant song. These lovely pygmies are cousins of the wrens; and one may sometimes see flitting about the brush a real wren, which in summer flies away to the far north, letting us hear for a few days in March, before he leaves, specimens of the exquisite song with which he will make the Canadian woods ring when next June he meets his mate and builds his nest among the great pines and spruces.

Most of our birds, you know, flee southward, when cold weather approaches, but some, like the crow, many birds of prey, as hawks and owls, some game-birds, such as Bob White and the grouse, several of the seed-eating sparrow tribe, and some others, such as the little fellows we have been watching, stay with us, because they find plenty of food.

If we should go out every day of the winter we could make a long list of these by the time All Fools' day came around. To it might be added a goodly list of birds whose proper home is in Northern Canada, but which in midwinter come south to a country which is less snowy if not less cold. The s...o...b..rds, with their satiny feet and ivory bills, dressed like gentlemen in lead-colored coats and white vests, to which you toss crumbs from the breakfast table every morning, are in this cla.s.s.

Doubtless we shall see others as we turn down the wooded lane that leads to the creek.

Here among these bushes is a good place to look for coc.o.o.ns of moths and b.u.t.terflies. One is pretty sure to see at once a few of those of the big Promethea moth folded within a large leaf, the stem of which is lashed by silk threads to its twig so that it will not fall or be blown away.

Very likely on the same bush will hang a similar big coc.o.o.n, but this one fastened all along the under side of the twig, so that it is hammock-shaped. Search about among the heaped-up leaves beneath the bush, and you may find the coc.o.o.ns of the great Polyphemus silkworm-moth and of that exquisite pale-green luna-moth which flits like a ghost to our lighted windows on summer nights.

But these are the giants of their race. Hundreds of smaller coc.o.o.ns and chrysalids--papery, fuzzy, leathery, or naked and varnished to keep out the damp, may be discovered in the crevices of the old fence, upon and beneath the rough bark of trees, rolled up in leaves little and big, and buried in the ground, where the moles hunt for them when the ground is not frozen too hard, and the skunks dig them up.

How about the moles and the skunks? Well, the moles are by no means as active as in summer, though they move around somewhat under the frozen layer of top-soil, in search of the earthworms which have been driven deep down by the frost. As for the skunks, they, like the woodchucks, the chipmunks, and the red squirrels, are deeply sleeping in underground beds; but plenty of four-foots are wide awake. See how that gray squirrel is making the snow fly as he paws his way down to the nut he buried three months ago! Only the tip of the plume of his tail waves above the drift.

Do you see that double row of holes punched in the snow? Every country boy knows them as the track of a rabbit, and would tell you how fast the rabbit was going. But what embroidered on the glistening snow-sheet this lovely chain that extends wavily from this tree to that stone wall? A weasel. Little cares he for cold, in his white ermine coat; and many's the careless sparrow, and snugly tucked-in mouse that falls to his quick spring and sharp white teeth. The weasel's nearest cousin, the mink, is working for his living, too, these winter days, haunting the warm spring-holes in hope of catching eels or other fish. Perhaps we shall see some signs of his work along the creek.

And now we have come to the end of the last of our rambles. But don't think that we have seen nearly all that there is to be seen. If we had been able to spend a little more time in the fields, or the lane, or the wood, or on the banks of the stream, we should have noticed a great many more animals and birds and reptiles and insects, quite as curious and quite as interesting as any of those which we have met with. And if we had taken a dozen rambles together instead of only four, each time we should have found fresh creatures to look at, and fresh marvels to wonder at, and fresh beauties to admire. For wherever we go nature always has something new to show us; and the world is full of wonderful sights for every one who has eyes to see.

NATURE-STUDY AT THE SEASIDE

Introduction

Many very curious and interesting creatures are to be found on the seash.o.r.e, and we dare say you would like to know something about them.

So let us take, in thought, four rambles along the sh.o.r.e together. First we will go for a stroll on the sandy beach, which is left quite dry for some little time when the tide goes down. Next, we will pay a visit to the stretches of mud just above low-tide mark, left bare in the coves for perhaps a couple of hours twice each day. For our third ramble we will wander about among the rocks, and examine the creatures which are crawling about on them, or burrowing into them, or hiding underneath the great ma.s.ses of seaweed with which they are covered. And then, lastly, we will search in the pools which lie between the rocks, where we shall probably find some of the most interesting animals of all.

We will suppose that these walks are on our Atlantic coast, for we have not time now to explore the sh.o.r.es of the Pacific and describe its animals, many of which are very different from those of the Eastern coast.

I

ALONG THE SANDY BEACH

As all the coast of the United States south of New York, and Cape Cod and Long Island besides, are formed of soil and pebbles ground off the tops and sides of the Appalachian ranges of mountains, the ocean beaches and the bottom of the sea near sh.o.r.e are all of sand, constantly swept by currents, and moved by storms. On such a plain of s.h.i.+fting sand not many plants or animals can live save those which are able to swim or to bury themselves; and not nearly so long a list can be made as among the rocks which give root-hold and shelter, or where the bottom is muddy, as we shall see later; yet a walk will enable us to find a good many things about which you ought to know something.

Here, for instance, are a lot of sh.e.l.ls, the hard outer coats of the soft boneless creatures we call mollusks, such as you know very well on land as snails. When you have filled your little basket, if we asked you to sort them into two kinds, you would be almost sure to put those which consist of two pieces, attached together, into one pile, and those which are in one solid piece, and more or less twisted like a snail, into the other. This would mark a real division, for the first heap would have the clam-like mollusks which we call bivalves, and the second would have those coiled gastropod mollusks that we may call sea-snails.

The bivalves scattered along the beach are all dead and mostly broken, for they have been washed up from muddy places; but many of the sea-snails may be found alive and belong here on the sand, and so we may look first at them.

Here is a big one to begin with which the southern fishermen call a conch and the northern oystermen a winkle. It is shaped like a pear, and pus.h.i.+ng out of its sh.e.l.l a very tough muscular part of its body called the foot, it plows along in the sand, or even burrows into it, small end first, searching for food, which consists of animal matter, either dead or alive. It finds this by its sense of smell, and when it comes to it, thrusts out of its head, near the forward end of the foot, a long ribbon-like tongue, covered with hundreds of minute flinty teeth, and rasps away the flesh. Winkles are numerous everywhere and are of great service in devouring dead fish, etc., which would pollute the water; but they also eat a great quant.i.ty of oysters, as we shall see presently.

You will find two kinds, and should note how their sh.e.l.ls differ.

Very likely you will find among the long rows of dead eel-gra.s.s and drift-stuff marking the reach of high tides a twisted string of most curious objects, each about as big as a cent, feeling as if made of yellow paper and strung together like a necklace on a stiff cord.

These are the eggs of a conch, or more truly, the egg-cases, for in each cent-like capsule was placed an egg. You can prove it by opening some of them. In the dry ones you will probably find only dead young sh.e.l.ls, hardly bigger than pin-heads, which have hatched from the eggs; but now and then you may pick up a soft and elastic set, and in these, which are alive, or have only lately been torn from the weeds in deep water and thrown upon the beach, you will find much larger baby conchs, which by and by would have found a way out and begun to travel about.

We have already picked up several different sorts of slender, twisted sea-snails of small size, and a few as big as a walnut and almost as round, save for the circular opening out of which the animal pushes its foot. His name is Natica, and he is one of the worst foes of the clam, whose sh.e.l.l he bores. Here, half buried in the wet sand at the edge of the gentle surf, is a living one, and we can see the grooved trail behind him showing where he has traveled. We will pick him up, and see how hastily he shrinks back into the armor of his sh.e.l.l, and shuts his door with a plate growing upon the tip-end of his foot. All these sea-snails have such a plate, sometimes thin and h.o.r.n.y like this one, sometimes thick and sh.e.l.l-like; and if you try to pry it away you will have to tear it to pieces, for the frightened animal will not let go its strong hold. He knows better than to open his door and let you pick him out. Even if you did you would have to tear his body out piecemeal, for he would by no means uncoil it from around the central post of his house and let himself be dragged out whole. This door is a good protection, then, against the claws of crabs and the nibbling teeth of fishes and various small parasites which would like to get at him. It is called an operculum.

Just lift up some of that seaweed and stuff which the waves have piled up. Why, the sand underneath it is simply alive with sandhoppers, besides various jumping and crawling insects, sand-bugs, spiders, etc.

But the sandhoppers are most numerous--there must be a hundred, all skipping about so actively that it is quite difficult to follow their movements. They were feeding upon the seaweed, and their sharp little jaws are so powerful that if you were to tie up a few sandhoppers in your handkerchief and carry them home, you would be almost sure to find that they had nibbled a number of little holes in it by the time that you got there! But surely such little creatures as sandhoppers cannot do very much good, even by eating decaying seaweed. Ah! but there are so many of them! Wherever the sh.o.r.e is sandy they live in thousands, and even in millions. If you walk along the edge of the sea, sometimes, when the tide is rising, you will see them skipping about in such vast numbers that the air looks as if it were filled with a kind of mist for a foot or eighteen inches from the ground. And though many of the sh.o.r.e-birds feed upon them, and some of the land-birds do so, too, and the sh.o.r.e-crabs eat a very great many, yet their numbers never seem to grow less.

These sandhoppers are small cousins of the crabs with which we shall get acquainted when we go to the mud-flat; and a search would find many others, such as beach-fleas of various kinds. Here and there are strange grooves, and--look! one of them is growing longer under our very eyes.

Dig away the sand just ahead of it, and see what you can find. There it is--a small ivory-like creature, about twice as big as a pumpkin-seed.

It is a sand-bug, or hippa, and it burrows along just under the surface, searching for minute particles of food among the grains and letting the sand fall in behind it, for it does not mean to make a tunnel.

One of the waste objects you tossed aside was a piece of wood which the waves have flung up, and which no doubt once formed part of a wrecked vessel.

"And I don't wonder!" some one exclaims, "if all the timbers were as rotten as that!"

The bit of timber is certainly ruined--but what has happened to it? It is full of long round burrows, each about big enough to admit a lead-pencil, and so close together that the walls between them are very little thicker than paper; and every burrow seems to be lined with a kind of glaze.

That is the work of a curious creature known the world over as the s.h.i.+p-worm, which often does a great deal of mischief by burrowing into the hulls of s.h.i.+ps and the timbers supporting wharfs and harbor-side buildings. It has a soft round body no bigger than a piece of stout string, and often nearly a foot in length. But it is really a sh.e.l.l-bearing mollusk, like the c.o.c.kle and the clam. And if you were to look closely at the fore end of its body you would see its bivalve sh.e.l.ls, although they are so very small that they might easily be mistaken for jaws.

When first this animal hatches from the egg it is not in the least like its parents. It is just a little round-bodied creature covered almost all over with hairs, by waving which up and down it manages to swim about in the water. But it does not keep its shape very long, for if you were to look at it about thirty-six hours later you would find that it was oval instead of round. Twenty-four hours later still it would be almost triangular, while next day it would be almost round again. And so it would go on changing its form day after day, till at last it fastened itself down by its fleshy foot to a piece of sunken timber and began to burrow in it. And then at last it would take the form of its parents.

The birth and growth of most of the bivalves is similar to this; and it must be remembered that these changing larval forms are hardly large enough to see.

Another timber-destroyer all along the New England coast is the gribble, a crustacean related to the sandhoppers, which is not bigger than a grain of wheat, and looks like a pill-bug. It devours wood wherever it finds it under water, and will gradually honeycomb and weaken until they fall to pieces the bases of piles, boat-stairs, and other timbers under water which are not sheathed with copper or filled with creosote.

Therefore it is much hated.

A sandy beach is not the place for crabs in general, but there is one kind which we ought to find here. There is one now, but one might wager something that you can't discover it in its hiding-place unless shown to you. Do you see those two little round objects on short stems sticking half an inch out of the sand by that old winkle-sh.e.l.l? Yes? Well, please go and get one or both of them. What! is it alive? some sort of crab, buried in the sand? All right--pick it up, but look out it doesn't nip you! Those claws are powerful, for with them the crabs must seize and firmly hold struggling, slippery fish and other animals, until it can subdue and eat them. Notice how the hind legs are flattened into strong paddles to enable it to swim swiftly upon its prey. In spite of these fierce qualities we call this one a lady-crab, because of its richly ornamented costume--greenish yellow profusely marked with purple rings.

It spends most of its time crawling or swimming in the sea where the bottom is sandy and the water shallow, but now and then comes ash.o.r.e and buries itself in the dry sand, all but its stalked eyes, as we found this one.

A smaller, lighter-colored, and more square-bodied cousin of this crustacean, called the ghost-crab, is very common on southern beaches, where it digs slanting burrows deeply into the sand. Prof. A. G. Mayer tells us that it is a scavenger, feeding on dead animals, and also catching and eating beach-fleas. It is at night that they are most active. "As they flit rapidly about in the moonlight their popular name of ghost-crab seems remarkably appropriate. As one approaches they dash off with great rapidity, and will often rush into the water, although the gray snappers are swimming close along the sh.o.r.e in order to devour them."

What have you found now? It appears to be a horseshoe-shaped skillet, or frying-pan, made of brown parchment, with a long spike loosely hinged to one side for a handle, and a big crab lying on its back in the pan. No wonder you are surprised. The first white men who came to this country were equally so, for nothing of the sort is to be seen in any other part of the world, except in the Malayan islands. If we search we are likely to find one alive and creeping about, and then we shall see that the skillet is a broad s.h.i.+eld covering the back of an animal, and that what we thought was the crab inside it, is its body and legs. When you come to study natural history more deeply you will learn many very interesting things about this strange inhabitant of our beaches, which is known as a horseshoe-crab, or king-crab, and also as limulus. It is the sole remnant of a great tribe of sea-animals called trilobites, which became extinct ages ago.

One more curiosity must be mentioned before we quit this first short walk upon the open beach--what the fishermen call the mermaid's-purse, of which, see, you have found several.

It is an egg, but you never would have suspected it, would you? Examine it. It is about two inches long, and made of a hard, black, leathery substance, and at each of the four corners there is a little projection about an inch in length. It is the empty egg of a skate--a fish of the shark tribe with a broad, flat body and a long whip-like tail--from which one of these curious fishes has just escaped. How do you think it got out of the egg when the time came for it to be hatched? Just look at this empty case, and you will see. At one end there is a slit running across it almost from one side to the other, made in such a manner that the little fish could easily push its way out, while none of its enemies could push their way in. So the baby skate lay in its cradle in safety till the time came for it to pa.s.s out into the sea.

But here is an egg made in just the same way, with one little difference. Instead of having a short straight projection at each corner, it has a long, coiled, twisted one, much like the tendril of a grapevine. That is the egg of one of the small sharks called dogfish, which are so called because they swim about in parties or packs of fifty or sixty together, driving herring and other fishes before them, as dogs drive deer. The skin of a dogfish is as rough as a piece of sandpaper.

When the eggs of this fish are first laid, the twisted projections at the ends coil themselves round the stems of weeds growing at the bottom of the sea, and hold them so firmly that they cannot be washed away; and at each end there is a small hole, so that a current of water may always flow through this egg-case and over the little fish inside--something of just as much importance to it as is a supply of air to a land-baby.

II

SEARCHING THE Sh.o.r.e AT LOW TIDE