英文科學(xué)讀本 第四冊(cè)·Lesson 40 More about Birds

Lesson 40 More about Birds

We have not yet finished our classification of the birds. The next order for us to consider are the waders. These birds have very long legs, for walking in the water. Hence they are sometimes known as stilt-walkers. They live on fishes, frogs, and other water animals. They have long necks to correspond with their long legs, and pointed bills for spearing their prey. They include the snipes, plovers, lapwings, and herons of England, and the stork, crane, flamingo, buzzard, and bittern of other lands.

The swimmers form the next order. Their distinguishing characteristic is the web between the claws. The webbed feet enable these birds to swim, and so specially fit them for a water life. They live in the water because they get their food out of the water. This is a large and important order; the most familiar members of it are the ducks, geese, and swans. Many of the family are marine birds. Among them are the gull, penguin, petrel, and albatross. The last is an immense bird, the largest of the order. It has marvellous powers of flight. The next order is known as runners, and includes a few large and powerful birds, which neither fly nor swim, but are extremely fleet on foot. The legs are exceedingly strong, and the broad thick toes are pointed forwards. As they do not fly, these birds have small wings; and they use the wings as balancers while running. The ostrich is the largest and most powerful of the group. It can run at the rate of twenty-six miles an hour. The emu and the cassowary belong to the same order.

Many of our smaller birds, while they differ very slightly in the structure of the claws, are capable of a further useful classification according to the form of the beak or bill. The blackbird, thrush, robin, nightingale, and other well-known birds live mostly on worms, grubs, and insects. These birds have the upper mandible notched near the point, for the purpose of securing their prey. Hence they are known as tooth-billed birds. They may be regarded, on the whole, as very good friends to the farmer, in devouring the worst of his destructive enemies, although they do now and then help themselves to a little of his fruit by way of dessert.

If you have ever watched a swallow skimming swiftly over a pool on a summer evening, you must have seen that the bird always flies with its mouth wide open. The mouth is slit some distance beyond the mandibles to admit of this. But what can be the object of such structure and habits? These birds live on insects, which they catch on the wing. The open mouth presents a wide-gaping flytrap, and the swift, skimming flight through the air is to assist them in catching their prey. The swallow, marten, swift, and goat-sucker belong to this group, which are known as wide-gaping bills.

A glance at the bill of a sparrow, a linnet, or a lark will show that it is short and conical in shape. It has the appearance of more strength than you might expect to find in so small a bill. These birds live mostly on seeds. Their short strong beaks are specially fitted for cracking and crushing the husks of the seeds. The group are known as cone-shaped bills.

The humming-birds of South America represent another group. They are all tiny little birds, with remarkably gorgeous plumage, although some of them are scarcely bigger than a bee. They frequent the flowers, some say for the sake of the insects in them, others for the sake of the sweet juice or nectar which they contain. Whether for one or both of these purposes, the bills have no hard work to do, and hence they are soft and slender. The group are known as the slender bills.