The May influx of warblers is one of the most glorious events of our spring bird migration. This quiet spectacle is essentially confined to eastern and central North America, as the west coast has far fewer warbler species. We have about 30 species of warblers come through our area every migration season. Fewer than half of these species stay into June to breed here, with most continuing farther north, many to the boreal forests of Canada.
The warblers are small birds, for the most part chickadee sized or smaller, and most have bright, colorful spring plumages, often involving bright yellow. Their songs are generally high-pitched, often with a buzzy quality.
The first few warbler species to show up in our area are Yellow-rumped, Pine, and Palm Warblers—these three first show up around early April, as they are all relatively short distance migrants that winter mostly in the southern US. They are followed by Louisiana Waterthrush (which, despite its name, is indeed a warbler) and Black-and-White Warbler, generally the first warblers to arrive back from the tropics. These two are in turn followed by a flood of later tropical-wintering species at the very end of April and beginning of May.
Many people are unacquainted with warblers, which is a great pity. Though few warbler species are especially wary, their small size and the fact they are generally present here only when trees and shrubs are leafed out often leads to them going unnoticed by those not looking for them. It is well worth the effort, as the warblers are the stars of the extraordinary diversity of colors and sounds of our annual avian visit from the tropics.