Farther down stream in a rough portion of the pasture, brambly but beautiful with barberries, is the chosen habitat of the yellow warblers of my neighborhood. Always they build in the barberry bushes here, nor have I ever found them anywhere else or in other bushes. It is not difficult to find them when the pasture is in the full leafage of late May, for you have but to go from one barberry bush to another till you have succeeded. But the yellow warbler is a shy bird, and I have known them to desert nest and eggs when these were too often visited.
It is much better to hunt them now, when you have but to stand on a little hillock and count, then pluck the nest that you prefer and take it home with you without abraiding anybody’s feelings. The yellow warbler mother bird seems to have a great love for the tender buff wool of the young shoots of the cinnamon fern, which are just about ready to shed these delicate overcoats when nesting begins with the yellow warblers. In fact, her color scheme is perfect.
The nest, when finished, is a symphony of pale buff and silvery grays that shade imperceptibly toward the buff touches on the under parts of the warbler and are lighted as with a gleam of sunlight by the bright yellow of the remaining plumage. Yet this bright yellow has a greenish tint that is deepened in the tender green of the young shoots of the barberry, while the yellow itself is again reproduced in the blossoms. No wonder this lovely little singing-bird loves a barberry bush for its nest. It finds protection and an artistically satisfying color scheme in the same bush.
The silvery grays of the nest are the fine, silky, fibrous inner bark of the milkweed, whose last year’s stems are shredded by wind and storm in time for the nest-building. These barberry-bush-building yellow warblers with whom I have been more or less acquainted for a quarter of a century seem to care for little else for material, though sometimes they make the fern fuzz more adhesive with caterpillars’ silk and line with a few horsehairs and soft feathers.
Yet though these nests have been invariable in material they have varied otherwise. Some have been so firmly woven and the material so stoutly packed as to defy the storms of a winter or two. Others have been so frail as hardly to be found when the leaves are off. Perhaps these slight nests are made by birds that were nestlings of the previous year and have not yet learned the complete art of nest-building.