In Allegany Park, N. Y., according to Aretas A. Saunders (1938); “Magnolia warblers seem to have territory and a definite singing location, but I have seen no animosity toward each other or other species of warblers, such as the black-throated green and blackburnian, birds that have very similar habits and live in the same habitat and sometimes sing regularly in the same tree. * * * Territories are evidently vertical as well as horizontal, that is measured in volume rather than area, so that a clump of big hemlocks furnishes space for several pairs and several species of hemlock-loving warblers.”
Courtship.—William H. Moore (1904) says: “During the mating season the males are pugnacious little fellows, and many fights do rivals have. They attack each other with much fierceness, seizing hold with their beaks, and hitting with half-opened wings they sprawl about on the ground, until thoroughly overcome. When pressing his suit to the female of his choice, the male displays his colors to great advantage, as they show in fine contrast among the bright green foliage of the trees.”
Nesting.—All the 14 or more nests that I have seen, in Maine, New Brunswick, Quebec, and Newfoundland, have been in small spruces or balsam firs growing in old clearings, in reclaimed boggy pastures, or along the edges of coniferous woods. These little trees were often less than 6 feet high and generally stood in dense thickets. The lowest nest I find recorded in my notes was only 12 inches above the ground in a tiny fir, and the highest was 8 feet up in a slender balsam in a thick clump of these trees in rather open woods; more nests were below 5 feet than above it. The nests usually rested on horizontal branches or twigs and against the trunk but in a few cases they were placed a few inches or a foot out on a branch.
Similar nesting habits seem to be characteristic of the magnolia warbler in other parts of northern New England, Nova Scotia, and southern Canada according to information received from others; and most of the nests have been placed at similar low levels, though Mr. Brewster (1938) found one near Lake Umbagog that was 25 feet from the ground. In this northeastern region an occasional nest has been found in a cedar, a larch, or a small hemlock, but at a height usually less than 5 feet.
In New York and Pennsylvania hemlock seems to be the favorite tree, and the magnolia warbler more often places its nest at a higher level and well out toward the end of a horizontal branch, where it is usually shaded and sometimes well concealed in dense foliage. Verdi Burtch, of Branchport, N. Y., wrote to Dr. Chapman (1907) that he found nests "in hemlocks usually on a horizontal limb from eight to twenty feet up and over an opening in the woods. Several nests were found in the top of little hemlock saplings from one to five feet from the ground. One nest was found by Mr. C. F. Stone in a birch sapling, this being the only instance to my knowledge of its nesting in a tree other than a hemlock.” He has sent me a photograph of a nest in a wild blackberry bush.
T. E. McMullen has given me the data for 14 nests of the magnolia warbler found in the Pocono Mountains, Pa.; 10 of these were located in hemlocks from 30 inches to 30 feet above the ground and from 6 to 12 feet out on the branches; one nest was 30 feet up and one 18, but the others were all less than 10 from the ground. The other 4 nests were in rhododendrons, in woods, or along the banks of creeks, and were from 2 to 3 feet up.
Edward A. Preble (Todd, 1940) says that “all but one of more than fifty nests of this warbler that R. B. Simpson has examined near Warren [Pa.] were placed in hemlocks. One nest was at the exceptional height of thirty-five feet; another was only a foot from the ground in some low hemlock brush.” Mr. Simpson’s other nest was in a witch-hazel, and Mr. Saunders reported one in a pin cherry, both under hemlocks.
The magnolia warbler is a poor nest builder; its nests are apparently carelessly built and are very flimsy affairs, much like poorly built nests of the chipping sparrow; and they are usually insecurely attached to their supports. Brewster (1877) gives the following good description of a typical nest: “The framework is wrought somewhat loosely of fine twigs, those of the hemlock being apparently preferred. Next comes a layer of coarse grass or dry weed-stalks; while the interior is lined invariably with fine black roots, which closely resemble horse-hairs. In an examination of more than thirty examples I have found not one in which these black roots were not used. One specimen has, indeed, a few real horse-hairs in the lining, but the roots predominate. This uniform coal-black lining shows in strong contrast with the lighter aspect of the outer surface of the nest.”
Miss Cordelia J. Stanwood, of Ellsworth, Maine, who has sent me some elaborate notes on the magnolia warbler, gives me this description of one of her best nests: “In this some hay and the fine tips of cinquefoil served as a foundation, but the greater part of the nest consisted of a fine black, vegetable fibre, resembling horsehair. So much of this hair-like material was used that, when the rim was frescoed with down from the willow pod, a person looking at the dainty abode in its setting of fir twigs could see nothing but the jet-black lining and the fluffy, silvery plant-down around the throat of the nest. The structure was partly pensile, being bound with spiders' silk to the two branches at right angles to the main stem.
“The front part of the base rested on the branches beneath. It was placed in a small fir, 2 feet from the ground, surrounded by a growth of fir and gray birches. * * * The nests were about 2 inches wide at the top on the inside and 11⁄4 deep. The wall at the top was 3⁄4 inch thick.””