Mr. Nuttall noticed this species passing through Massachusetts about the 15th of April. He regarded it as an active insect-hunter, keeping in the tops of the highest trees, darting about with great activity, and hanging from the twigs with fluttering wings. One of these birds that had been wounded soon became reconciled to its confinement, and greedily caught at and devoured the flies that were offered. In its habits and manners it seemed to him to greatly resemble the Chestnut-sided Warbler.
Mr. T. M. Trippe speaks of this Warbler as one of the last to arrive near Orange, N. Y. Owing to the fact that at that time the foliage is pretty dense, and that it makes but a short stay, it is not often seen. He speaks of it as not quite so active as the other Warblers, keeping more on the lower boughs, and seldom ascending to the tops of the trees.
Mr. C. W. Wyatt met with this species at Naranjo, in Colombia, South America.
Eggs of this bird obtained by Mr. George Bush at Coldwater, near Lake Superior, are of an oblong-oval shape, measuring .75 by .52 of an inch, and except in their superior size and fewer markings might be mistaken for eggs of D. æstiva. Their ground-color is a bluish or greenish white. The markings are very few and fine, except those in the crown around the larger end, and there the blotches are deeper and more numerous. Their colors are dark reddish-brown and purple.
Mr. Maynard found this species the most abundant of the Sylvicolidæ at Lake Umbagog, where it breeds. Two nests were taken in June. One was found June 3, in a tree by the side of a cart-path in the woods, just completed. It was built in the horizontal branch of a hemlock, twenty feet from the ground, and five or six from the trunk of the tree. By the 8th of June it contained three fresh eggs. The other was built in a similar situation, fifteen feet from the ground, and contained two fresh eggs.
These nests were large for the bird, and resembled those of the Purple Finch. They were composed outwardly of fine twigs of the hackmatack, with which was mingled some of the long hanging Usnea mosses. They were very smoothly and neatly lined with black fibrous roots, the seed-stalks of Cladonia mosses, and a few hairs. They had a diameter of about six inches,
and a height of about two and a half inches. The cavity was three inches wide and an inch and a quarter deep. The eggs varied in length from .71 to .65 of an inch, and in breadth from .53 to .50. Their ground-color was a bluish-green, thickly spotted with brown, and generally with a ring of confluent blotches of brown and lilac around the larger end. Occasionally the spots proved to be more or less of an umber-brown, and in some specimens the spots were less numerous than in others.
These birds were found in all the wooded sections of that region, where they frequented the tops of tall trees. Their song, he states, in its opening, is like that of the Black-Poll, with a terminal warble similar to that of the Redstart, but given with less energy.
Dendroica cærulescens, Baird.
BLACK-THROATED BLUE WARBLER.