Warbler Waves Are Coming!
A highlight of May is the eagerly anticipated arrival of warblers -- the small, colorful perching birds or “Passerines”. These tiny creatures typically weigh less than half an ounce and display their vibrant plumage upon their spring arrival. While the Americas boast New World warblers, Europe and Asia host Old World warblers, which are in a very different family and are far less colorful. New World warblers alone encompass nearly 120 different types, with New England home to about 50 species.
Warbler Migration
The males who breed here arrive a week before the females. They sing throughout their chosen territory and fight territorial battles regarding defended territories. The females pick the males with the best territory, plumage and song. At the same time other warbler species that do not nest here, practice their songs and by late May continue on to areas in northern New England and eastern Canada. It is possible to record up to two dozen kinds of warblers on "warbler wave days" when southwest winds follow rain events and/or northerly winds.
In the fall, warblers migrate southward to destinations like the southern U.S., the Caribbean, Central America, or South America. Among warblers, Blackpoll Warblers stand out as migration champions, undertaking remarkable journeys of up to 12,400 miles round trip from the Canadian Arctic to South America each year!
Warbler Identification
Warblers display a rich array of colors, ranging from predominantly yellow hues to those with splashes of yellow in their plumage. Some are characterized by black and white patterns, while others lean towards brownish tones, and a select few boast predominantly blue shades. It's no surprise that the spring migration, marked by the presence of warblers, is a favorite time of year for many birdwatchers. As late summer approaches, some warblers undergo a molt, transitioning into the duller colors of their nonbreeding feathers, making them more challenging to identify.
Identifying warblers can be both exhilarating and demanding for bird enthusiasts. During the spring migration, when foliage is abundant, spotting them becomes particularly challenging. This is where honing birding-by-ear skills becomes invaluable. The fall migration of warblers poses its own set of challenges, with numerous plumage variations to navigate. Many male warblers lose their vibrant spring colors during molt, adopting a more subdued appearance, while females often lack the vivid hues of their male counterparts. Additionally, first-year birds may not yet have acquired their adult plumage, adding further complexity to identification efforts.
Warbler Songs and Calls
Warblers exhibit remarkable vocal variety, captivating us with their diverse and intricate melodies as they migrate. Developing proficiency in birding-by-ear skills becomes essential in distinguishing between the myriad of songs they produce. Recognizing the tunes of different warbler species demands dedication, patience, and practice. Their songs encompass a broad spectrum, from the familiar sweet, sweet, sweet, I'm so sweet refrain of the yellow warbler to the blue-winged warbler's bee-like buzz rasp.
Warbler Nests and Diet
Warblers exhibit diversity both in their nesting habits and dietary preferences. Their cup-shaped nests, constructed from grass, bark, and various plant materials, can be found in various locations, including nestled within tree or shrub branches, suspended in reeds and sedges, or even placed directly on the ground. Warblers primarily rely on bugs for their diet, including beetles, spiders and caterpillars which they gather from the ground or foliage. Remarkably, certain species like the American Redstart showcase their agility by catching prey mid-flight.
May is an exciting time to explore birds in New England, yet it passes quickly, so get out and enjoy it!
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Learn About Warblers by taking our Spring Migration in New England Course.
Can you identify the warblers? Mouse over for the answer.
