
Photo by
cottonmanifestoUrban species #127: Yellow-rumped Warbler
Dendroica coronataMillions of tons of tiny inchworms, feeding on the buds and flowers of trees, fuel one of Boston's most wonderful natural events. The city is in the middle of the migration route for dozens of bird species, including a large group of small insectivorous birds called warblers. For a few brief weeks in May, attentive nature lovers have an opportunity to see these tiny transients as they eat caterpillars on their way to Canadian breeding grounds. For many birders, it is the beginning and the main highlight of the birding year. Their often secretive habits, and sometimes subtle differences in song and markings make identifications challenging and rewarding.
Familiarity, as we urban nature lovers know all too well, breeds contempt. Thus it is that the most frequently encountered warbler is denigrated by experienced birders as "butterbutt." The yellow-rumped warbler also can feed on flying insects, and so is not as dependent on the temporary supply of early-instar caterpillars. And while many of their close relatives prefer high treetops and dense woods, yellow-rumps like more open areas. The yellow-rumped (or "myrtle"--isn't that better?) warbler may be the most common warbler in the bunch, but as the vanguard of a major migration, it's also one of the most welcome.