While on a recent foray in Shawnee State Forest, I came across a number of individuals of three of the early-bird arrivals in the warbler world. These three – Pine Warbler, Yellow-throated Warbler, and Black-and-white Warbler – are among the first to return to Ohio, often by March’s end. Life is tougher for largely insectivorous birds that return before leaf-out. Once the foliage materializes, far more caterpillars can be found, and little wriggly larvae make the warbler world go ‘round. But these three have evolved specializing feeding niches that frees them from the need for leafy trees.
Beautiful male Pine Warbler poses briefly in a Red Maple, Acer rubrum. They are hardy; nearly the entire population winters in the U.S., and some stick it out in Ohio. A more apt name couldn’t be found: Pine Warblers and pine trees go together like apples and pie.
older timber stands. The tree above is one of the largest American Chestnuts, Castanea dentata, known in Ohio. This formerly abundant component of eastern forests was decimated by disease and now persists rarely as stump sprouts or the odd big tree. Chestnuts would have supported many a Black-and-white Warbler, but now they use other trees such as oak and tulip.
These three species of warblers, along with early returning Louisiana Waterthrushes, beat the crush of other warblers, in part because their specialized feeding styles enable them to exploit niches where food can be found. Most of the other warblers come later, following the arboreal wave of flowering and leafout of forest trees as spring rolls northward, taking advantage of the bonanza of insects that emerge with the foliage.