* * * * *

We see then that the scratching birds live nearly all over the world, yet, no doubt, it is a disadvantage to them that in their ground life they have become so heavy that they cannot fly so lightly or so far as their near allies, the pigeons, which, like them, feed on the ground. For the Pigeons have already made many steps forward in life. Their wings are strong, so that they can fly for great distances; their toes are slender and well fitted for perching; and though it is true that our tame pigeons and the wild rock-pigeons from which they are descended do not build nests, but lay their eggs in dovecots or church towers, or, if they are wild, in holes in the rocks, yet the beautiful blue-gray wood-pigeon, with her pure white collar and soft cooing note, builds a nest in the trees—

“The stock-dove builds her nest

Where the wild flowers’ odours float;”

though it is but a rough one, made, as well as her weak feet and bill can do it, of a few stout twigs, laid so loosely that her two little white eggs may be seen from below, and even sometimes fall through.

Fig. 42.

Wood-pigeon on her nest.

Yet, though but a beginner in nest building, she is a true tree bird, and her little ones are born naked and helpless, far out of reach of the ground, and must be fed and cared for till they can fly. So she feeds them with infant pap from her own mouth. The “crop” or bag in which the partridge or hen stores the grain she picks up is large and single; but the pigeon has two bags, one on each side of the throat, and when she is feeding her young these bags secrete a large quantity of milky fluid, which, mixing with the tender shoots she has pecked off in the spring, or with the oily seeds she has gathered for her autumn brood, makes a soft food, which she pours into the mouths of her nestlings till they fly and feed themselves.

In the pigeons, then, we are gradually rising from the ground birds,—where the father generally has many wives[101] and the young ones run as soon as they are hatched,—to the tree birds, where father and mother, taught by the helplessness of their brood, share the cares of nest building and the pleasures of love. Even the pigeons did not all at once become tree birds, for we have them in all stages now from the ground to the air. Many years ago, in the island of Mauritius, there were heavy flat-breasted pigeons, the Dodos, which lived entirely on the ground without the power to rise, so that when the Dutch settled there, bringing rats with them in their ships, the Dodos soon fell victims to the intruders, and now there is not one left. Again, in New Guinea now, there are ground pigeons which fly heavily and slowly, and only go to the trees to roost. Then come our own tame pigeons, the rock-pigeons, and the stock-dove which builds in boles in the trees; and then our wood-dove and his relations, with their rude nests and their mixed food of grain and grass. And among these are the wonderful long-winged passenger pigeons[102] of America, which fly in flocks of hundreds of thousands through Ohio, Kentucky, and Indiana, in search of nuts and seeds, breaking down the boughs of the trees by their weight where they alight, and then darkening the whole sky as they start off again in a succession of vast multitudes to another forest where beech nuts, acorns, and chestnuts are plentiful, or to the rice-grounds of Carolina, to take their fill.