B ESIDES the birds which live and feed on the land there are a great many which live mostly on the water. Some of these are called "waders," and some are "swimmers" and have webbed feet. We read about two waders, the coot and the moorhen, in Book II. To-day we will talk about the swimming birds.
If you live by the seaside, you will know the gulls which float on the sea, and often fly a long way up the rivers. Gulls come up the river Thames as far as London, and feed in the ponds of the parks. In the winter it is a pretty sight to watch them circling round and round, and catching the food which people throw to them.
You may have seen Cormorants (see p. 38), big black birds which fly heavily over the sea, with their long necks stretched out and their narrow wings beating the air. Then they settle on the water, and suddenly jump up and dive down head foremost, presently coming up with a fish, which it takes them often some time to swallow.
But if you live in the country near a large lake or a river, you are more likely to see a curious little swimming bird called the little Grebe or dabchick. This is a brown bird with a thin neck and head, which paddles about among the reeds on the bank of a river, or swims along quietly, diving down every now and then to catch water-snails, fish, or weeds. You will have to move very quietly if you want to get near the dabchick, for it dives down at the least alarm and comes up a long way off, out of sight.
If you have not seen any of these web-footed birds, nor even a wild duck yet every child knows the tame Duck which lives in our farmyards. Our ducks and drakes were tamed long, long ago from wild ducks, and are still very like them. Let us see what we can learn about a duck.
First I want you to look at her as she waddles across the yard. Her feet have a skin between the three front toes which joins them together. That is to say she is "web-footed." Now notice that, as she lifts her foot, the skin folds up like a fan, and when she puts her foot down, it spreads out again. When she reaches the pond, she glides into the water and begins to paddle, using one foot after the other, just as you do when you walk. In clear water you can see that as she puts her foot forward the skin shuts up, as it did when she walked, but when she puts it back and strikes the water, it opens and makes a paddle, and so she rows herself along.
Her legs grow far back on her body, so that she can use them to twist and turn herself about, and she can tip her head and body down into the water to look for water-snails and tadpoles, while she paddles along with her tail up in the air.
Next notice how light her body is. It floats quite on the top of the water. This is partly because she has a layer of light fat under her skin, and partly because she has a thick covering of down under her feathers. There is a great deal of air caught in this down, and this makes her light.
Do you know why her feathers do not get wet and draggled in the water? The reason is very curious. Her outer feathers are all smeared with oil which she gets from a little pocket near her tail. Look at her when she comes out of the water. She presses her beak against her tail and then draws the feathers through the beak. When she has oiled them in this way, they are water-proof and keep the wet off her body.
Next watch her as she feeds. She goes gobble, gobble through the mud, and often throws her head up to swallow something she has found. Her beak is broad and flat. It is hooked at the tip, but higher up it is covered with a soft skin full of nerves. With this skin the duck feels what is in the mud as well as if she saw it. The tip and edges of the beak are very horny and sharp, and, both above and below, it is lined with thin strips of horn. When she closes her beak these strips fit into each other and make a strainer. With her sharp beak she cuts the weeds or kills the snails. With the strainer she sifts the mud and keeps the food in her mouth, forcing out the water with her thick tongue. Geese, swans, and all wild ducks have feet and beaks much like our farmyard duck.
You may have seen wild-ducks in the lakes or rivers. The drake is a very handsome bird. His head and neck are a dark shiny green. He has a white collar, and his breast is the colour of a chestnut. His wings and back are partly brown and partly green. The four middle feathers of his tail are a glossy black and curl up. The others are grey, edged with white. When the wild drake changes his coat in June he puts off this beautiful plumage, and puts on a plain brown and grey suit, like the mother duck, till August. Then he begins to moult again, and in October is as gay as before.
The cormorants and gulls have not beaks like the duck, for they do not grope in the mud. Their bills are sharp and strong for fishing, and their wings long for flying. The little dabchick, on the contrary, has short wings, as he chiefly floats on the water. His beak is not very long, and it has no hook at the end. His feet are rather large, but the web is not wide as in ducks.
There are a great many other web-footed birds. Try if you can find some.
Examine a dead duck. Notice the webbed foot, the parts of the beak, the thick down, and the glossy oiled feathers not wetted in water. Draw the foot of any dead bird you can find.