One reason why dead birds and animals are so rarely found is, that on the approach of death their instinct prompts them to creep away in some hole or under some cover, where they will be least liable to fall a prey to their natural enemies. It is doubtful if any of the game-birds, like the pigeon and grouse, ever die of old age, or the semi-game-birds, like the bobolink, or the "century living" crow; but in what other form can death overtake the hummingbird, or even the swift and the barn swallow? Such are true birds of the air; they may be occasionally lost at sea during their migrations, but, so far as I know, they are not preyed upon by any other species. The valley of the Hudson, I find, forms a great natural highway for the birds, as do doubtless the Connecticut, the Susquehanna, the Delaware, and all other large water-courses running north and south. The birds love an easy way, and in the valleys of the rivers they find a road already graded for them; and they abound more in such places throughout the season than they do farther inland. The swarms of robins that come to us in early spring are a delight to behold. In one of his poems Emerson speaks of "April's bird, Blue-coated, flying before from tree to tree;" but April's bird with me is the robin, brisk, vociferous, musical, dotting every field, and larking it in every grove; he is as easily atop at this season as the bobolink is a month or two later. The tints of April are ruddy and brown,--the new furrow and the leafless trees,--and these are the tints of its dominant bird. From my dining-room window I look, or did look, out upon a long stretch of smooth meadow, and as pretty a spring sight as I ever wish to behold was this field, sprinkled all over with robins, their red breasts turned toward the morning sun, or their pert forms sharply outlined against lingering patches of snow. Every morning for weeks I had those robins for breakfast; but what they had I never could find out. After the leaves are out, and gayer colors come into fashion, the robin takes a back seat. He goes to housekeeping in the old apple-tree, or, what he likes better, the cherry-tree. A pair reared their domestic altar (of mud and dry grass) in one of the latter trees, where I saw much of them. The cock took it upon himself to keep the tree free of all other robins during cherry time, and its branches were the scene of some lively tussles every hour in the day. The innocent visitor would scarcely alight before the jealous cock was upon him; but while he was thrusting the intruder out at one side, a second would be coming in on the other. He managed, however, to protect his cherries very well, but had so little time to eat the fruit himself that we got fully our share.