(Conurus carolinensis), we next arrive at the cuckoos and kingfishers, which differ widely in their habits. The blackor yellow-billed cuckoos or rain-crows are shy, retiring birds, with drab plumage, and though seldom seen are often fairly abundant, and are of much service in destroying insects. Unlike their shiftless European relatives, which lay their eggs in the nests of others birds, they build their own airy homes in some bush or hedgerow, and raise their brood with tender care. The belted kingfisher (Ceryle alcyon) is also of a retiring disposition, and spends much of its time on some branch overlooking the water, occasionally varying the monotony by dashing after a fish, or flying with rattling cry to another locality. Their nests are built in holes in banks, and six or eight young are annually reared.

214. The woodpeckers (Pici).-The woodpeckers are widely distributed throughout the world, and are preeminently fitted for an arboreal life. The beak is stout for chiseling open the burrows of wood-boring insects, which are extracted by the long and greatly protrusible tongue. The feet, with two toes directed forward and two backward, are adapted for clinging, and the stiff feathers of the tail serve to support the bird when resting. Almost all are brightcolored, with red spots on the head, at least in the males, which may further attract their mates by beating a lively tattoo with their beaks on some dry limb. The glossy white eggs are laid in holes in trees, and both parents are said to share the duties of incubation and feeding the young. Among the more abundant and well-known species is the yellowhammer or flicker (Colaptes auratus), which extends throughout the United States. Somewhat less widely distributed is the red-headed woodpecker (Melanerpes erythrocephalus), and the small black-and-white downy woodpecker (Dryobates pubescens). This is often called sapsucker, but incorrectly so, as, like all but one of our other woodpeckers it feeds on insects. The yellow-bellied wood

pecker (Sphyrapicus varius) is a real sapsucker, living on the juices of trees. A close relative of the red-headed woodpecker, the California woodpecker (Melanerpes formicivorus), is renowned for its habit of boring holes in bark and inserting the acorns of the live oak. Subsequently the bird returns, and breaking open the acorns, devours the grubs which have infested them, and apparently eats the acorns also.

215. Swifts, humming-birds, etc. (Macrochires).-The birds of this order are rapid, skilful fliers, and their wings are very long and pointed. The feet, on the other hand, are

FIG. 127.-Night-hawk (Chordeiles virginianus) on nest. Photograph by H. K. JOB.

small, relatively feeble, and adapted for perching or clinging. Accordingly, the insects upon which they feed are taken during flight by means of their open beaks. The night-hawk (Chordeiles virginianus), roosting lengthwise on a branch by day, at nightfall takes to the wing, and high in the air pursues its food after the fashion of a swallow. In the same haunts throughout the United States the whip

poorwill (Antrostomus vociferus) occurs, sleeping by day, but active at night. Neither of these birds constructs nests, but lays its streaked and mottled eggs directly on the ground. The chimney-swifts (Chatura pelagica), swallowlike in general form and habits, but very unlike the swallows

in structure, frequent hollow trees or unused chimneys, to which they attach their shallow nests. The nearly related humming-birds are chiefly natives of tropical America, only a few species extending into the United States. Of these the little, brilliantly colored, and pugnacious ruby throat (Trochilus colubris) is the most widely distributed. Its nest, like that of other hummers, is composed of moss and lichens bound together with cobweb and lined with down.

216. Perching birds (Passeres). The remaining birds, over six thousand in all, belong to one order, the Passeres or perchers. They are characterized by great activity, interesting habits, frequently by exquisite powers of song, and in addition to several other structural arrangements have the feet adapted for perching. Their nesting habits

differ widely, but in every case the young are helpless at the time of hatching, and require the care of the parents.

The perchers constitute the greater number of the birds living in the meadows and woods, and are more or less

FIG. 129.-Anna hummer (Calypte anna) on nest.

common, and consequently familiar everywhere. Among the families into which the order is divided that of the flycatchers (Tyrannida), the crows and jays (Corvida), the orioles and blackbirds (Icterida), the finches and sparrows (Fringillida), the swallows (Hirundinida), the warblers (Mniotiltida), the thrushes, robins, and bluebirds (Turdida), are the more familiar, though the others are equally interesting.

CHAPTER XVIII

THE MAMMALS

217. General characteristics.-The mammals, constituting the last and highest class of the vertebrates, comprise such forms as the opossum and kangaroo, the whales and porpoises, hoofed and clawed animals, the monkeys and man. All are warm-blooded, air-breathing animals, having the skin more or less hairy. The young are born alive, except in the very lowest forms, which lay eggs like reptiles, and for some time after birth are nourished by milk supplied from the mammary glands (hence the word mammals) of the mother. The skeleton is firm, the skull and brain within are relatively large, and, with few exceptions, four limbs are present.

Most of the mammals inhabit dry land. A number, however, such as the whales and seals, are aquatic; while others, such as the beavers, muskrats, etc., though not especially adapted for an aquatic life, are, nevertheless, active swimmers, and spend much of their time in the

water.

Mammals tend to associate in companies, as we may witness among the ground-squirrels, prairie-dogs, rats, mice, and the seals and whales. In many cases they band for mutual protection, and often fight desperately for one another. Claws, hoofs, and nails are efficient weapons, and spiny hairs, as on the porcupines, bony plates, such as encircle the bodies of the armadillos, and thick skin and hair, serve as a protection. The hair is also frequently colored to harmonize the animal with its surroundings.