Two days afterward (July 31st) I went to the western end of the wood, and found the influx there much smaller than on the opposite side; but I arrived late, and made a partial count only. After sunset 186 birds were seen, whereas there had been 455 entries at the eastern end, two nights before, during the same time.
Thus far I had always been too late to witness the beginning of the flight. On the evening of August 1st I resolved to be in season. I reached the border of the pond at 5.15, and at that very moment a single robin flew into the wood. No others were seen for eighteen minutes, when three arrived together. From this time stragglers continued to appear, and at 6.30 I had counted 176. In the next ten minutes 180 arrived; in the next five minutes, 138. Between 6.45 and 7, I counted 549; then, in six minutes, 217 appeared. At 7.25, when I concluded, the figures stood at 1533 birds. For about twenty minutes, as will be noticed, the arrivals were at the rate of thirty-six a minute. Throughout the thickest of the flight I could keep a lookout upon only one side of me, and, moreover, the gathering darkness was by that time making it more and more difficult to see any birds except such as passed above the dark tree line; and from what went on just about me, it was evident that the number of arrivals was increasing rather than diminishing as my count fell off. There seemed to be no good reason for doubting that at least two thousand robins entered the wood at the eastern end.
Two nights later I stationed myself in the meadow southwest of the roost. Here I counted but 935 entries. The movement appeared to be fully as steady as on the opposite side, but as darkness came on I found myself at a great disadvantage; a hill occupied the background, giving me no illuminated sky to bring the birds into relief, so that I could see only such as passed close at hand. Of the 935 birds, 761 came before seven o'clock, but it was reasonably certain that the flight afterward was nearly or quite as great, only that I wanted light wherewith to see it.
On the evening of August 4th I went back to the eastern end, and as the sky was perfectly clear I hoped to make a gain upon all my previous figures. But the fair weather was perhaps a hindrance rather than a help; for the robins came later than before, and more in a body, and continued to arrive long after it was impossible to see them. I counted 1480,—53 less than on the 1st.
I attempted no further enumeration until the 18th. Then, in an hour and ten minutes, 1203 birds were seen to enter the roost at the eastern end. But they arrived more than ever in flocks, and so late that for much of the time I missed all except the comparatively small number that passed in my immediate vicinity. Many were flying at a great height,—having come from a long distance, as I inferred,—and sometimes I knew nothing of their approach till they dropped out of the sky directly over the wood. On this occasion, as well as on many others,—but chiefly during the latter part of the season,—it was noticeable that some of the robins appeared to be ignorant of the precise whereabouts of the roost; they flew past it at first, and then, after more or less circling about, with loud cackling, dived hurriedly into the wood. I took special note of one fellow, who came from the south at a great altitude, and went directly over the wood. When he was well past it he suddenly pulled himself up, as if fancying he had caught a signal. After a moment of hesitation he proceeded on his northerly course, but had not gone far before he met half a dozen birds flying south. Perhaps he asked them the way. At all events, he wheeled about and joined them, and in half a minute was safe in port. He had heard of the roost, apparently (how and where?), but had not before visited it.
This count of August 18th was the last for nearly a month, but I find a minute of August 27th stating that, while walking along the highway on the westerly side of the roost,—the side that had always been the least populous,—I saw within less than two minutes (as I calculated the time) more than eighty robins flying toward the wood. Up to this date, then, there could not have been any considerable falling off in the size of the gathering. Indeed, from my friend's observations upon the Belmont roost, to be mentioned later, it seems well-nigh certain that it was still upon the increase.
Toward the close of August I became interested in the late singing of several whippoorwills, and so was taken away from the robins' haunt at the hour of sunset. Then, from the 5th to the 13th of September, I was absent from home. On the night of my return I went to the shore of the pond, where, on the 1st of August, I had counted 1533 entries. The weather was favorable, and I arrived in good season and remained till the stars came out, but I counted only 137 robins! It was plain that the great majority of the congregation had departed.
As I have said, there was little to be learned by going into the wood after the robins were assembled. Nevertheless I used frequently to intrude upon them, especially as friends or neighbors, who had heard of my "discovery," were desirous to see the show. The prodigious cackling and rustling overhead seemed to make a deep impression upon all such visitors, while, for myself, I should have had no difficulty in crediting the statement had I been told that ten thousand robins were in the treetops. One night I took two friends to the place after it was really dark. All was silent as we felt our way among the trees, till, suddenly, one of the trio struck a match and kindled a blaze of dry twigs. The smoke and flame speedily waked the sleepers; but even then they manifested no disposition to be driven out.
For curiosity's sake, I paid one early morning visit to the roost, on the 30th of July. It would be worth while, I thought, to see how much music so large a chorus would make, as well as to note the manner of its dispersion. To tell the truth, I hoped for something spectacular,—a grand burst of melody, and then a pouring forth of a dense, uncountable army of robins. I arrived about 3.40 (it was still hardly light enough to show the face of the watch), and found everything quiet. Pretty soon the robins commenced cackling. At 3.45 a song sparrow sang, and at the same moment I saw a robin fly out of the wood. Five minutes later a robin sang; at 3.55 another one flew past me; at four o'clock a few of the birds were in song, but the effect was not in any way peculiar,—very much as if two or three had been singing in the ordinary manner. They dispersed precisely as I had seen them gather: now a single bird, now two or three, now six, or even ten. A casual passer along the road would have remarked nothing out of the common course. They flew low,—not as if they were starting upon any prolonged flight,—and a goodly number alighted for a little in the field where I was standing. Shortly before sunrise I went into the wood and found it deserted. The robin is one of our noisiest birds. Who would have believed that an assembly of thousands could break up so quietly? Their behavior in this regard may possibly have been influenced by prudential considerations. I have said that many of them seemingly took pains to approach the roost indirectly and under cover. On the westerly side, for example, they almost invariably followed a line of bushes and trees which runs toward the roost along the edge of the meadow, even though they were obliged sharply to alter their course in so doing.