One fair morning, while several of us were scrambling through one of the thickets of trees, scarcely waist-high, my youngest son chanced to scare from her nest a female of the Black-poll Warbler. Reader, just fancy how this raised my spirits. I felt as if the enormous expense of our voyage had been refunded. "There," said I, "we are the first white men who have seen such a nest." I peeped into it, saw that it contained four eggs, and observed its little owner looking upon us with anxiety and astonishment. It was placed about three feet from the ground, in the fork of a small branch, close to the main stem of a fir tree. Its diameter internally was two inches, the depth one and a half. Externally it resembled the nest of the White-crowned Sparrow, being formed of green and white moss and lichens, intermixed with coarse dried grass; within this was a layer of bent grass, and the lining was of very dark-coloured dry moss, looking precisely like horse-hair, arranged in a circular direction with great care. Lastly, there was a thick bed of large soft feathers, some of which were from Ducks, but most of them from the Willow Grouse.
I must now return to the United States, and trace the progress of our Warbler. It enters Louisiana as early as the middle of February. At this time it is seen gleaning food among the taller branches of the willows, maples, and other trees that overhang the rivers and lakes. Its migrations eastward follow the advance of the season, and I have not been able to comprehend why it is never seen in the maritime parts of South Carolina, while it is abundantly found in the State of New Jersey close to the sea shore. There you would think that it had changed its habits; for, instead of skipping among the taller branches of trees, it is seen moving along the trunks and large limbs, almost in the manner of a Certhia, searching the chinks of the bark for larvæ and pupæ. They are met with in groups of ten, twelve, or more, in the end of April, but after that period few are to be seen. In Massachusetts they begin to appear nearly a month later, the intervening time being no doubt spent on their passage through New York and Connecticut. I found them at the end of May in the eastern part of Maine, and met with them wherever we landed on our voyage to Labrador, where they arrive from the 1st to the 10th of June, throwing themselves into every valley covered by those thickets, which they prefer for their breeding places. It also breeds abundantly in Newfoundland.
In these countries it has almost become a Flycatcher. You see it darting in all directions after insects, chasing them on wing, and not unfrequently snapping so as to emit the clicking sound characteristic of the true Flycatcher. Its activity is pleasing, but its notes have no title to be called a song. They are shrill, and resemble the noise made by striking two small pebbles together, more than any other sound that I know. They may be in some degree imitated by pronouncing the syllable sche, sche, sche, sche, sche, so as progressively to increase the emphasis.
I found the young fully grown in the latter part of August, but with the head as in the females, and like them they obtain their full plumage during the next spring migration, after which these birds return southward. They raise only one brood in the season, and if any of them breed in the United States, it must be in the northern parts. They are seldom seen in autumn in the States, and very seldom during the summer months.
The Black-poll Warbler is a gentle bird, by no means afraid of man, although it pursues some of its smaller enemies with considerable courage. The sight of a Canadian Jay excites it greatly, as that marauder often sucks its eggs, or swallows its young. In a few instances I have seen the Jay confounded by the temerity of its puny assailant.
The occurrence of this species so far north in the breeding season, and the curious diversity of its habits in different parts of the vast extent of country which it traverses, are to me quite surprising, and lead me to add some remarks on the migration of various species of Sylvia, which, like the present, seem to skip, as it were, over large portions of the country.
In the course of my voyages to the south-eastern extremity of the Peninsula of the Floridas, I frequently observed birds of many kinds flying either high or low over the sea. Of these the greater number were, like the present species, Sylviæ which are never found in Georgia or the two Carolinas. Their course was a direct one, and such as led me to believe that the little voyagers were bound for Cape Hatteras. The meeting with many of the species to which I allude, along the shores of Maryland, New Jersey, the eastern coast of Long Island, &c., and all along to the Bay of Fundy, has strengthened the idea; but as I may not be correct, I leave the matter to the determination of more experienced observers. The subject appears to me to be one of the greatest importance, for the occurrence of plants in certain parts of a country and not in others may possibly be caused by the absence, during migration, of such birds as move by "short cuts" from one point of land to another.
Sylvia striata, Lath. Ind. Ornith. vol. ii. p. 61.—Ch. Bonaparte, Synops. of Birds of the United States, p. 81.
Sylvicola striata, Swains. and Richards. Fauna Bor.-Amer. part ii. p. 218.
Black-poll Warbler, Sylvia striata, Wils. Amer. Ornith. vol. iv. p. 40. pl. 30. fig. 3. Male; and vol. vi. p. 10. pl. 49. fig. 4. Female.—Nuttall, Manual, part i. p. 383.