This boy discovered for himself the screech owls' strange characteristic of changing their colour without changing their feathers, as moulting song birds change theirs. They have a rusty, reddish-brown phase and a mottled-gray phase. So far as is known, these changes of colour are not dependent upon age, sex, or season. No one understands what causes them or what they mean. Sometimes the same family will contain birds with plumage that is rusty-brown or gray or intermediate. But you may always know a screech owl by its small size (it is only about as long as a robin) and by the ear tufts that make it look wide-awake and very wise. By day it keeps well hidden in some deserted woodpecker's hole or a hollow in some old orchard tree, which is its favourite residence; but some mischievous little birds, with sharper eyes than ours, often discover its hiding place, wake it up, and chase it, blinking and bewildered, all about the farm. By night, when its tormentors are asleep, this little owl goes forth for its supper, and then we hear its weird, sweet, shivering, tremulous cry. Because it lives near our homes and is, perhaps, the commonest of the owls all over our country, every child can know it by sound, if not by sight. [Illustration] Father and mother barn owls [Illustration] The heavenly twins: young barn owls {233} CHAPTER XVI MOURNER, WHISTLER, AND DRUMMER Mourning Dove Bob-White Ruffed Grouse {234} {235} MOURNING DOVE _Called also: Carolina Dove_ Do not waste any sympathy on this incessant love-maker that slowly sings _coo-o-o, ah-coo-o-o-ooo-o-o-ooo-o-o_, in a sweetly sad voice. Really he is no more melancholy than the plaintive pewee but, on the contrary, is so happy in his love that his devotion has passed into a proverb. Nevertheless, the song he sings to his "turtle dove" sounds more like a dirge than a rapture. While she lives, there is no more contented bird in the woods. Dove lovers are quite self-sufficient. Their larger cousins, the wild pigeons, that once were so abundant, depended on friends for much of their happiness and lived in enormous flocks. Now only a few pairs survive in this land of liberty to refute the adage "In union there is strength." Because millions of pigeons slept in favourite roosts many miles in extent, they were all too easily netted, and it did not take greedy men long to turn the last flock into cash. Happily, doves preserved their race by scattering in couples over a wide area--from {236} Panama, in winter, as far north as Ontario in warm weather. Not until nursery duties, which begin early in the spring, are over, late in summer, do they give up their shy, unsocial habits to enjoy the company of a few friends. When they rise on whistling wings from tree-bordered fields, where they have been feeding on seeds and grain, not a gun is fired: no one cares to eat them.