In the spring/summer these warblers are found in mature coniferous and mixed coniferous-deciduous woodlands feeding on insects including caterpillars, ants, leaf beetles, grasshoppers and spiders. This makes them a very winter hardy bird allowing them to winter farther north than other warblers. This bird has unique gastrointestinal traits that allow it to subsist on this unusual food source. During this time they mainly eat berries and fruits, particularly wax-coated berries of bayberries and wax myrtles. In winter, Yellow-rumped warblers can be found in open pine and pine-oak forests and dunes where bayberries are common. The female is brownish with the similar patterns. Its rump, crown and small area at the sides of the breast are yellow. In the spring before they leave Seabrook Island, the male is dark blue-gray upper parts white throat, breast and belly are white and heavily streaked with black. In winter, the females, males and young are a paler streaked gray-brown, have bright yellow rumps and usually yellow side patches. The Yellow-rumped is medium-sized warbler with a long narrow tail and stout dark bill. This bird constantly “chirps” which is a contact call that keeps the flock together.

You will see them in small flocks in open woodlands and brushy habitats. They arrive in November and depart in April. On Seabrook, Butter Butts are our most obvious and widely distributed winter Warbler. It was formally called Myrtle Warbler in the East because it is the only Warbler able to digest the wax-coated berries of the Wax Myrtles. The Yellow-rumped Warbler is sometimes referred to as “Butter Butt” due to its bright yellow rump. Yellow-rumped Warblers are one of the most common warblers in North America and abundant on Seabrook Island from fall through spring. Yellow-rumped Warbler – Setophaga coronata

Yellow rumped warbler range map