The Yellow-rumped Warbler (Setophaga coronata), formerly referred to as a Myrtle Warbler, is not hard to find during its migration due to the large numbers that pass through (as well as stay to breed in) central and northern New England. These tiny jewels, also known as “butter-butts” because of their bright yellow rumps, are common and widespread.
Yellow-rumps are known for the diversity of their feeding techniques as well as their diet. You are as likely to find them clinging to a tree, probing under bark or foliage gleaning for insects as you are finding them taking short bursts of flight off of a branch to snag an insect in the air. These warblers are insect-eaters during the summer and consume a large amount of fruit during the winter. Their ability to digest the waxes in bayberries makes them unique among warblers, and allows populations to winter along the coast as far north as Nova Scotia.
The presence of “pantaloons” on this image of a male Yellow-rumped Warbler may be due to courtship behavior. Males hop from perch to perch, fluff out their feathers, raise their wings, erect their crown-feathers, and continuously chip in an effort to attract a female.
Should you choose to use your ears to locate this coniferous forest-loving warbler, its song can be heard at http://musicofnature.com/mary-holland/yellow-rumped-warbler/ . (Sound recording © Lang Elliott – langelliott.com)