two ways we can explain the absence of these birds: either those that were accustomed to occupy it went to a new locality, and the single bird that had preceded them, finding his companions did not come, left, rather than remain alone; or he left to announce that food would be scarce, for it must be remembered, as Darwin has remarked, "most animals and plants keep to their proper homes, and do not needlessly wander about; we see this, even with migratory birds, which almost always return to the same spot." At any rate, the summer of 1874, in this neighborhood, was the driest in the past forty years, and it seemed as if the chewink knew what was coming. So, at least, we believe. During this season we noted the entire absence, during the summer, of several migratory birds, common, as a rule, and a very marked decrease in the numbers of those that did appear; but, at the same time, our note-books mention the arrival of one or more individuals of every one of our migratory birds. Many, like the chewink, foresaw what was coming and acted accordingly. It would be most interesting to determine if insect-life was less abundant than usual during the past summer, but concerning this we have only to note, as suggestive that it was so, a marked freedom of the fruit-trees and fruit itself from the attacks of their insect enemies.
Another feature of the migration of our inland birds must here be briefly referred to; and that is, the failure of late years of certain species to come, as a rule, as far north as New Jersey; and also the habit, now fully acquired by others, of remaining throughout the year, when, but a comparatively short time ago, these same birds were truly migratory.
As an instance: the summer red-bird (Pyranga æstiva), twenty years ago, was a regular visitor to Central New Jersey, arriving about May 1st and remaining until October. It nested on trees, frequently in apple-orchards, laying pretty purple-blotched, green eggs. It preferred wooded hill-sides with a growth of underbrush, and having a southern exposure. In such situations they were numerous, and to one such locality, in particular, we can well remember the charm they added to the scene by the bright gleam of their plumage as they passed from tree to tree, uttering their peculiar but not melodious notes. For the past fifteen years we have seen not half a dozen individuals, and recorded no nests since 1857. In far scantier numbers the scarlet tanager (Pyranga rubra) has taken their place, although this bird is not rare by any means, nor was it so when the preceding species was abundant.
It is much the same with the mocking-bird (Mimus polyglottis). Formerly, as regular in its appearance, if not as abundant, as the catbird, it is now among our rarest summer visitors. An occasional pair, selecting some well-tangled thicket, will come late or early, and build their nest, and then half a dozen years may elapse before we see them again. Yet, thirty years ago these birds were common.
