Page:Popular Science Monthly Volume 7.djvu/198

186 year. We have fewer instances recorded of single swallows, seen at unusually early dates, than of birds of any other family. Some, indeed, arrive much earlier than do others, as, for instance, the bank-swallow; but the variation in date of arrival, throughout any ten years, is certainly much less than with other birds, and with some of them it is surprisingly regular, but not absolutely so, as so often asserted.

Let us now glance at the peculiarities of this family of birds, and compare them with the thrushes and warblers. One marked difference at once is seen; that is, that the swallows have a wonderful flight-power, and the thrushes and warblers are weak in their powers of flight, positively as well as comparatively: and our observations bear us out in asserting, as a law of migration, that its regularity is in proportion to and solely dependent on the flight-powers of the species. With the entire list of inland birds of New Jersey, we believe this to hold good.

We have already expressed our belief that many birds have the ability to foretell a coming storm. As this is not directly connected with the subject of our essay, as we are now considering it, we will pass to another feature of this prophetic power, as it apparently is, in birds, and that is, their ability to judge of the general character of the coming season, by a visit of a few days' duration early in spring. We have so frequently noticed that certain birds, common to a locality during the summer, occasionally fail to visit it, except one or two individuals, that in April come for a few days, that it has appeared to us that these "pioneer" birds saw satisfactory reasons for believing that there would be a scarcity of food, and so return to meet their fellows, and informing them, they all depart to "fresh fields and pastures new," just as a single crow, discovering danger, will turn a whole colony from their course as they are going to their roosting-place. This, be it understood, is our supposition, and may be wholly untrue; but how are we to interpret the meaning of any habit or particular movement of a bird, except by the human standard? An act on the part of a bird is intelligible to us only as we would interpret a corresponding act in man; and these acts in birds and men, producing allied results, indicate that close connection between all animal life which is so readily comprehended from an evolution stand-point. Now, as an instance of this "foretelling" power in birds, we noted, during the past spring, the arrival of the first chewink (Pipilo erythrophthalmus) on April 27th. Busily among the dried leaves and tangled briers it hopped, enlivening the thicket with its constant song just as a dozen of its kind had done throughout the preceding summer. In a few days it had disappeared, and not a chewink has been seen or heard for nearly six months. Now a few are noticed on their way south from the country north of us. This locality is one where these birds usually congregate, and we have often found a dozen nests in the limits of the spot. But a few miles away, these birds were as abundant as usual. In