“Who was the fool that time?” cried Jules, in high delight.
“It certainly was the sparrow, sealed up in its narrow prison and left to perish.”
“Caught, you nest-robber!” Emile exclaimed, clapping his hands.
“The chimney-swallow or house-swallow, also called barn-swallow, has chestnut-red forehead, throat, and eyebrows, a black back with violet sheen, and a white breast and stomach. Its name of house-swallow is given to it because it seeks man’s neighborhood and even nests inside our houses, especially where there is but little commotion or noise. Open and empty rooms, sheds and coach-houses, the eaves of roofs, the under side of balcony floors, and the inside of tall chimneys are its chosen nesting-places. The nest itself is made of moistened clay mixed with straw and hay and furnished inside with feathers and dry grass. It is in the shape of a half-cup wide [[227]]open at the top. The eggs are five in number, white with small brown and violet spots.
“The house-swallow is the most interesting of the tribe. It is the farmer’s cheery companion and the guest of the barn, while the martin prefers towns and the cornices of monuments. Its characteristic cry is a sweet little song which the father, perched on the edge of the nest, keeps repeating to the brooding mother to beguile the long hours of incubation. This bird is found all over the world. It reaches us after a long migration about the first of April, twelve days before the martin and a month ahead of the swift.
“The sand-martin is smaller and of less frequent occurrence than the other two swallows of which we are speaking. Its back is mouse-gray in color, as are also its cheeks and a wide stripe across the chest, while breast and stomach are pure white. With its beak and claws—poor tools for such rough work did not energetic good will supply the deficiency—it tunnels into steep sand-banks by the waterside, or into the face of cliffs and the walls of quarries, making a hole with a narrow entrance and extending in a winding passage for nearly two feet. At the further end a little space is hollowed out and furnished with a thick bed of straw, dry grass, and feathers, all heaped together with no art. There are laid five or six slightly translucent white eggs. The sand-martin perches only on rocks, to which it clings easily with its long and pointed claws. It haunts the water’s edge, which it explores in rapid flight, darting [[228]]to and fro and snapping up the gnats attracted by the coolness.”
“It is said,” remarked Jules, “that swallows take long journeys.”
“Yes, all our swallows migrate every year, not from a love of wandering but from necessity. Many other birds, particularly those that live on insects, do the same. Swallows, like bats, live entirely on flying insects, and when cold weather comes these are lacking. What does the bat do then to keep from starving?”
“It goes to sleep,” answered Emile.
“Yes, it closes as tightly as it can the draft in the vital stove—that natural stove, you know, that gives us heat, movement, and animation by burning up our blood with the help of air. The bat almost stops its breath in order to economize the fuel stored up in its little veins and make it last until the reappearance of insects at the approach of summer. In a word, it goes to sleep in the depths of some grotto, falling into an unconsciousness resembling death. Birds, however, cannot thus save their fuel. Their little stoves are always burning away under forced draft, because of the violent exercise of flying. Their temperature, summer and winter, is forty-two degrees, centigrade, whereas man’s is only thirty-eight. When such a fire has to be kept going, imagine if you can take a six months’ nap because there was nothing to eat in the larder. It is quite out of the question. What, then, do birds do?