The Animal World, A Book of Natural History Part 40

One of the largest of all the sea-birds is the albatross, which is found chiefly in the tropical seas. When the wings are fully spread, they sometimes measure nearly twelve feet from tip to tip. Yet the entire weight of the bird is not more than sixteen or seventeen pounds. It often remains at sea for weeks or months together, sometimes remaining in the air all through the night as well as all through the day, and following s.h.i.+ps for hundreds of miles in order to feed upon the refuse which is thrown overboard. Its appet.i.te is enormous, for it has been known to gulp down a great piece of whale's blubber, weighing between three and four pounds, and then to return almost immediately for more!

Great numbers of albatrosses nest together on uninhabited islands, each pair scooping together a quant.i.ty of clay, gra.s.s, and sedge, which they arrange in a conical heap about ten or twelve inches high, with a little hollow at the top. Only a single egg is laid, which is quite white, and is rather larger than that of a goose.

THE PUFFIN AND THE PENGUIN

Two most curious birds must be mentioned in conclusion. The first of these is the puffin, which is found plentifully in one or another species on all northern coasts where there are bold cliffs. An odder and more quaint-looking bird it would be difficult to imagine, for it has a beak quite large enough for a bird six times its size, while that beak, which is banded with bright crimson, gray, and brilliant yellow, looks just as if it had been stuck on with glue! More than that, it does not appear to fit very well; so that altogether, with its short, squat body and stout little legs, the puffin is by no means a graceful bird. It is often known as the sea-parrot.

On dry land, the puffin is very awkward, and can only waddle along slowly and clumsily. But it is a good swimmer and diver, and can chase and overtake small fishes with the greatest of ease. It is also able to fly very well, and takes long journeys over the sea when it comes to us in the spring, and again when it goes southward in the autumn. It makes no nest, but finds a cranny, digs out a hole in the face of a cliff to the depth of about three feet, and lays a single grayish-white egg at the end of the hole.

Odder still is the penguin, whose wings are but little more than flippers, with scales on their upper edges instead of feathers! It cannot fly, of course; but it uses its wings for two purposes. For if it is frightened upon land it throws itself down on its breast and scuttles along on all fours, just as though its wings were legs, and if it wants to chase a fish in the sea it swims with them, just as though they were paddles.

There are a good many different kinds of penguins, all of which are found in the southern hemisphere. On some of the islands in the Pacific and Antarctic oceans they are found in immense numbers, and have a curious way of standing side by side upon the sh.o.r.e in long rows, with their flippers hanging down on either side of their bodies. From a distance, indeed, they might almost be mistaken for lines of soldiers standing at attention. When the breeding-season begins they become very busy, picking up stones, carrying them about with a great deal of fuss, and then carefully arranging them in position, every now and then turning their beaks up to the sky, waving their flippers, and making a curious gobbling noise. If a sitting hen leaves her nest for a little, all the other hens become greatly excited, and peck at her as she pa.s.ses by in order to drive her back again, croaking loudly in chorus, and evidently feeling extremely indignant with her for neglecting her duties.

When these odd birds are sitting on a ledge of ice, and want to get down into the sea, they often throw themselves upon their b.r.e.a.s.t.s, and "toboggan" down the slope into the water!

REPTILES

CHAPTER XXVII

TORTOISES, TURTLES, AND LIZARDS

We now come to the cold-blooded animals, which are divided into three cla.s.ses. First we have the reptiles, whose hearts are formed of three chambers, and which breathe air by means of lungs. Next come the amphibians, which are like the reptiles in many ways, but which have to pa.s.s through a tadpole stage before they reach the perfect form. And, thirdly, there are the fishes, whose hearts are divided into two chambers only, and which breathe water by means of gills.

TORTOISES AND TURTLES

At the head of the reptiles stand the tortoises and turtles, whose bodies are shut up in a kind of h.o.r.n.y box, which we generally call the sh.e.l.l. In reality, however, it is not a sh.e.l.l at all; for the upper part, which we call the carapace, is a development of the spine and the ribs, while the lower part, which is known as the plastron, is a development of the breast-bone. These animals, in fact, have part of their skeletons inside their bodies and part outside; so that they are really shut up in their own bones!

The so-called sh.e.l.l of a tortoise or a turtle is always very hard and strong, so that you can stand upon quite a small tortoise without hurting it in the least and in most cases the head and legs can be tucked away inside it, so that the animal is safely protected from almost every foe.

None of the turtles and tortoises have any teeth. But the edges of their jaws are so sharp and h.o.r.n.y that they can often inflict a very severe bite. Some of the larger turtles, indeed, could snap off the fingers of a man's hand as easily as you could bite through a carrot!

[Ill.u.s.tration: TYPES OF WATER-BIRDS

1. Mandarin Duck. 2. Penguin. 3. Heron. 4. Pelican.

5. Bittern. 6. Flamingo. 7. Crane.]

LAND-TORTOISES

The most famous of all the tortoises is the common land-tortoise, or Greek tortoise, which is found in many parts of the south of Europe, and also in Asia Minor. This is the animal which is so often kept as a pet, and about which so much pleasant literary interest has gathered. It does not grow to any great size, but will live in a garden for many years, crawling about by night as well as by day. Early in the autumn it buries itself underground, and falls into a deep sleep, from which it does not awake until the spring.

This tortoise is a vegetable-feeder, and is very fond of lettuce leaves, more especially when they are quite crisp and fresh, so that it can easily nip them to pieces with its sharp jaws. If they are rather old and stringy, it will hold them down with its front feet while it tears them asunder. And if you keep one of these animals as a pet, and want to give it a great treat, there is nothing that it likes better than a little milk. It is amusing to see how it drinks, for it first scoops up a little milk in its lower jaw, just as if it were using a spoon, and then holds up its head in order that the liquid may trickle down its throat.

There are a good many other kinds of land-tortoises, some of which grow to a very great size. The largest of all comes from the Galapagos Islands, and is quite a giant; for some of them are more than four feet long, and weigh between eight and nine hundred pounds! These huge creatures, however, are now nearly extinct.

TURTLES

The turtles are distinguished from the tortoises by the structure of their feet, which are flattened out in such a way as to serve as paddles in the water. For this reason these reptiles hardly ever come upon land except when they want to lay their eggs; and they can swim so well that they are often met with many hundreds of miles out at sea.

One of the best known of these creatures is the hawksbill turtle, which is so called because its mouth is shaped just like the beak of a hawk.

The carapace is made up of thirteen large scales, which overlap one another for about a third of their length, just like the slates on the roof of a house.

These scales are very valuable, for the best tortoise-sh.e.l.l is obtained from them. When they are first taken from the animal they do not look like tortoise-sh.e.l.l at all, for they are dull and crumpled and brittle.

But after they have been boiled, and steamed, and pressed for some hours they quite change their character, and become so soft that they can easily be molded into any required shape.

The eggs of this turtle are laid in a hole which the mother sc.r.a.pes in the sand, and are hatched by the heat of the sun. As soon as the little turtles make their appearance they hurry off as fast as they can toward the water. But they are very good to eat, and a number of hungry animals and birds are always on the lookout for them, so that a very great many are snapped up and devoured before they can plunge into the waves.

The famous turtle soup, which is considered so great a dainty, is made from the flesh of the green turtle, which is found most plentifully off the island of Ascension and in the West Indies. It grows to a great size, for it is often four feet six inches in length and three feet in breadth, while it may weigh nearly three-quarters of a ton. Of course it is not at all easy to capture such big creatures. But they are generally pursued when they come on sh.o.r.e to lay their eggs, and are turned over on their backs by means of a lever. They are then perfectly helpless, and can be left lying where they are until a number of others have been overturned in the same way, when they are lifted into a boat one by one, and are taken on board s.h.i.+p. There they thrive quite well if a pail of water is thrown over them two or three times a day, and are generally in very good condition when they reach this country.

It is said that if one of these turtles has once begun to lay her eggs in the sand, nothing will induce her to pause in her task until she has finished it, and that even if the eggs are taken away from her as fast as she lays them, she will still go steadily on just as if she were undisturbed.

CROCODILES AND ALLIGATORS

Of course you know what these huge creatures are like. They are just enormous lizards, fifteen, or twenty, or even thirty feet long, with very short legs, and very clumsy bodies, and very long tails. And their great jaws are armed with rows of most terrible teeth.

But what is the difference between crocodiles and alligators? Well, in some ways they are certainly very much alike; but you can always tell them by the shape of their heads, for the muzzle of a crocodile is always narrowed just behind the nostrils, while that of an alligator is not. And in the crocodiles the fourth lower tooth fits into a notch in the edge of the upper jaw, so that you can distinctly see it even when the mouth is closed.

All these creatures live in the water, and spend a great deal of their time lying motionless on the surface, when they look like floating logs.

One would think that they were fast asleep. But woe betide any animal which comes to drink from the bank close by, for one of the great reptiles instantly dives, swims swiftly along under water, and knocks it into the stream by a blow from its mighty tail.

There is scarcely any animal which does not fall a victim at times to these giant lizards. And as soon as the unfortunate creature is knocked into the water it is dragged beneath the surface, and held there until it is drowned. You would think that the reptiles themselves would be drowned, wouldn't you, as they have to remain submerged for many minutes with their jaws widely opened? But they have a very curious valve at the back of the throat, and as soon as the mouth is opened this closes so tightly that not even the tiniest drop of water can find its way down the throat.

Both crocodiles and alligators swim with very great speed by waving their powerful tails from side to side in the water. They can run, too, with some little pace upon land. But it is very easy to avoid them, for the bones of their necks are made in such a way that they cannot turn their heads, and all that one has to do if pursued is to spring suddenly to one side. But of course it is necessary to avoid the stroke of the tail.

The crocodiles always lay their eggs in the sand on the bank of a river.

The eggs are about as big as those of a goose, and are generally buried at a depth of a couple of feet. The mother reptile always sleeps on the top of the nest, and it is said that when the little ones are ready to hatch out they utter a curious little cry. The mother hears this, and scoops away the sand under which they are buried, in order that they may have no difficulty in making their escape.

Crocodiles are found in the warmer parts of Africa, Asia, America, and Australia, and in some of the larger rivers are very plentiful. Just now and then they venture down into the sea. Alligators, which also are known as caymans and jacares, are only found in America and place their eggs in holes dug in the mud or earth beside the water. In the colder parts of the range they burrow under the mud of the banks and spend the winter in sleep.

THE LIZARDS

Lizards look at first glance like diminutive alligators, because most of them have long-jawed heads, short legs wide apart, and long tails; but really they are near relatives of the snakes, for not only their internal structure but the coat of scales is snake-like; but an important difference is that the jaws of the lizard are firmly hinged to a solid skull, while the bones of the skull of the snake, including those of the jaws, are connected by elastic cartilages which enable them to spread apart and permit the swallowing of a mouthful astonis.h.i.+ngly large. But the lizards have no need of such a convenience, for they subsist almost wholly on insects, or else are vegetable-eaters. Lizards are almost entirely denizens of the tropics, and seem to rejoice in the fiercest heat. They will lie contentedly in the desert at noonday on rocks so hot that they would blister your hand if you touched them.

Therefore few are to be found in Europe or North America, except in the extreme south.

THE BLINDWORM