But, all the while, he is watching you with the other eye, for he is a wary little bird, and not to be taken by surprise. _If_ you can get near him, you will notice his rather long yellowish legs, greyish-brown back, and, more than all, the white collar round his neck, and the black band showing on his white chest. Again we see the black-and-white markings which are so useful to the bird of the sh.o.r.e.
Everyone who knows the Ringed Plover loves to watch him. He is one of the daintiest, most fairy-like birds. When he is picking up worms and sand-hoppers on the wet sand he is easily observed. But wait! He flies off and settles on the shingle not far away. You walk nearer, to watch him. Alas! he is gone. You know just where he settled, yet he is gone!
He has often played that trick on me.
The secret lies in his grey, white-and-black markings. When our ships were in danger from enemy submarines, our sailors painted them with queer stripes and bars, to make it hard for the enemy to see them.
Nature has marked the Ringed Plover on the same plan. The feathers are so coloured and the colours are so arranged that, once among the grey, yellow, black, and white pebbles on the beach, the little bird is invisible. It is as if the earth had swallowed him up.
The eggs, too, are just as hard to find. There is no nest to "give the game away"; and the eggs look just like the pebbles amongst which they are laid. The young ones are protected from their enemies in the same way, and they crouch, as still as death, amid the stones which they so much resemble.
Now let us leave the beach and look for the Redshank on the mud-flats.
Many birds would starve there, but the Redshank is quite happy, as Nature has fitted him for his life in such a place. His long, red legs--from which he gets his name--are for wading in the shallow, muddy creeks he loves. Those wide-spreading feet keep him from sinking in the mud.
The long beak is for probing. As a rule the Redshank digs for his dinner, though he also picks up any worms or other food on the surface; but he is nearly always seen probing the mud.
Like all the sh.o.r.e birds, Redshanks are very wary. They have no hedges or trees for hiding-places, and so must always be on the watch. No sooner does the Redshank spy you than he is up and, with a shrill whistle of alarm, flies quickly away.
The marshes are the home of many a bird like the Redshank. They are all waders and diggers. They live much as he does, and so they have the long beak and legs, and the spreading feet, to fit them for that life.
We have now looked at a few sea birds, sh.o.r.e birds, and a marsh bird.
Many inland birds, too, are fond of the sh.o.r.e. The artful Jackdaw builds in the cliffs, and his cousin, the Crow, searches the sh.o.r.e for food.
Even the gay Kingfisher has been seen diving in the seaside pools.
1. How do you know which is the Black-headed Gull in the summer months?
2. Why is it difficult to see the Ringed Plover on the stones of the sh.o.r.e?
3. Where would you look for the eggs of the Ringed Plover and of the Black-headed Gull?
4. Why have marsh birds such long beaks?
Little Crabs are to be found everywhere along the sea-sh.o.r.e--not the monsters of the fishmonger's shop, but small greenish-brownish Crabs.
They live in the weed of the rock-pools, and in the wet sand. These are the Sh.o.r.e Crabs; the large Edible Crabs are a different kind, and live mostly in deep water.
Sh.o.r.e Crabs are quarrelsome little creatures; the larger ones are always ready to gobble up the smaller ones, or to s.n.a.t.c.h their food and run away with it. If you put some dead mussels or fish in a pool, you will be amused at their antics. How they scramble and fight! Crabs do not believe in "table manners."
[Ill.u.s.tration: THE REDSHANK.]
[Ill.u.s.tration: THE CRAB.]
It is their taste for waste sc.r.a.ps of food that makes crabs of use in the sea. They are most useful scavengers. They clear the sea and beach of dead matter which would poison the air and water.
For many years n.o.body knew how Crabs grew up. It was thought that a baby Crab was like its mother, just as a baby spider is a tiny picture of its parent. But no, the young Crab is as much _like_ a Crab as a caterpillar is like a b.u.t.terfly.
Let us begin at the beginning--the egg. Mother Crab carries her eggs with her, under her tail, which itself is always kept tucked up under her body. Out of each egg there comes the queerest little creature! It is just large enough to be seen as it wriggles in the water. Then its skin splits, and there appears a quaint thing with long feathery legs, a big head, a spike on the back of its head, and another spike like a nose.
Who would suspect this strange atom would turn into a Crab! Well, n.o.body did. It was called a _zoea_; but you can call it a Crab caterpillar or larva. The maggot is the larva of the fly, and the zoea is the larva of the Crab. With crowds of its brothers and sisters, the zoea kicks about on the surface of the sea. Fishes, and even great whales, swallow these tiny things by the million.
The Crab larva eats and grows. Again and again its skin splits, and a rather different zoea appears. This happens about once a week, until, hey presto! the spiked zoea is now rather like a Crab. The spikes are gone, and now it has tiny claws, and two eyes at the end of stalks. Yet it still owns a tail. At last this is tucked up under its body, and lo!
our little friend has changed into a very small Crab. No longer able to swim about, it comes to get a living in the shallow pools of the sh.o.r.e.
Luckily, this helpless baby knows how to hide. He is helped by his colour, for it matches the green and brown of the weeds and rocks. He knows how to dig himself into the sand, and work his sh.e.l.l well down.
Then only his funny eyes on stalks peer up at you. At this time of his life he has to "make himself scarce," and s.n.a.t.c.h his food when and where he can.
[Ill.u.s.tration: PURSE CRAB.]
We do not eat these little Crabs, but other Crabs do, and so do anemones, gulls, and other hungry creatures; and they themselves hunt sand-hoppers, and eat anything they can find or steal. So they grow bigger; and then, like the boy who grows quickly, the Crab finds his sh.e.l.ly suit a size too small for him!
Now look at his suit. It is a hard coat, a complete suit of armour to protect his soft body. Our picture shows the Lobster, the Crab's cousin.
The Shrimp and Prawn and Lobster are relations of the Crab; these _crustaceans_, as they are called, are all cased up in a hard _crust_, which will not stretch the slightest little bit. But the Crab's body _must_ grow! What is he to do?
At first he starves himself, and so his body shrinks inside its old sh.e.l.l. He loosens himself as well as he can. Soon the sh.e.l.l breaks across, and the Crab struggles to get free. At last he backs out, and leaves his old suit for ever. It is a wonderful performance, for he has withdrawn even from the legs, claws, feelers, bristles, eye-stalks and eyes! The old sh.e.l.l is left quite whole--a perfect Crab, but with no Crab inside it!
Now the Crab, in his new suit, hides away. He knows that he is a soft, flabby creature at this time, and that other animals, even Mrs. Crab, would be glad to meet him--and eat him. While his covering is yet soft he grows quickly. When it is hard, he ventures out again, ready to quarrel and fight.
This change of sh.e.l.l happens often to young Crabs. Older ones change only once a year. All the different kinds of Crab begin life as _larvae_ or _zoeas_, and cast their sh.e.l.ls as we have seen.
Crabs can see and hear and smell; and they must also have a fine sense of touch. I was once watching a big Crab eating his dinner under a rocky ledge in a large gla.s.s tank. As he tore his food, some of the bits, no larger than crumbs, fell and settled on the rocks below. Then I saw that a smaller Crab, with long pincers, was hiding under a rock. As the crumbs fell, he reached out his pincers and picked them up, one by one.
Each bit was gravely carried to his mouth, and tucked in, and then he reached out for another. Though I was very close to the Crab, I could hardly see the tiny sc.r.a.ps which he was able to pick up so easily.
One of the strangest Crabs is the Hermit. You would think that Nature had played a joke on him, for he has only half a suit of armour. His tail part is soft. He would have a bad time in the sea, but for a dodge he has learnt.
The baby Hermit takes the empty home of a periwinkle. As he grows he needs a larger house, and so leaves the tight sh.e.l.l and pops his tail into a bigger one, generally a whelk sh.e.l.l. If he meets with another Hermit there is a battle, one trying to steal the other's sh.e.l.l. Our coloured picture, page 35, shows some Hermits at war. Fighting, house-hunting, and moving house seem to be the Hermit's favourite pursuits. But, whatever he does, his first care is to protect that soft tail of his. His right claw is large and strong, so he uses it to close the door of his stolen home.
Sometimes he has a lodger who lives on the roof. This lodger, as you will notice in our coloured picture, is the sea anemone. The Hermit and his lodger seem to be good friends, at least they seem to like each other's company. There is no doubt that there are good reasons for this.
We shall have more to say about this strange pair in our lesson on the sea anemones.
[Ill.u.s.tration: HERMIT CRAB IN WHELK'S Sh.e.l.l.]
Another funny Crab is the Spider Crab. Its back is covered with reddish bristles, like so many hooks. These catch in the seaweed, and soon the Spider Crab is decorated with bits of weed. But that is not all. The artful Crab tears off other pieces of weed with its pincers, and attaches them to the hooks. It is another dodge, of course, to escape from enemies. The Lobster, whose picture you see, has a life-story much like that of the Crab. He, also, grows too big for his suit of armour, and casts it off in a wonderful manner, but only after a great deal of trouble. In his new suit he is very weak and soft--an easy prey to the first enemy to find him. He cannot defend himself then; he can only lie helplessly on his side, waiting for his coat to harden. He is so weak that his soft legs cannot bear the weight of his body.
[Ill.u.s.tration: HERMIT CRABS FIGHTING.]
Needless to say, the Lobster always finds a secure retreat before casting off his protecting coat of armour. A hole under a rock suits him well at that time. Strange to say, he seems to dislike his old clothes, and often crunches them to pieces or eats them up, or even pushes them under the sand or stones! Then he marches out like a proud warrior, knowing his strength, and the power of his great claws.
Lobsters are fond of fighting, and must be very disagreeable neighbours.
They can swim along by using the little "swimmerets" under their bodies.
Or, by rapidly bending down their powerful tails, Lobsters are able to shoot backwards through the water at a great pace. In our next lesson we shall find that Prawns are also able to paddle forwards or dart backwards in a similar way.
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