The Yellow-rumped Warbler has one of my favorite bird nicknames.  Each Yellow-rumped Warbler has a patch of bright yellow feathers low on its back, right above the base of the tail.  Many birders call them “butter-butts.”  Those yellow feathers are easy to see as these active, acrobatic warblers jump and fly from branch to branch in search of food.

Most other warblers fly far away from Pennsylvania during the winter, seeking tropical climates rich with insects and other foods.  Yellow-rumped Warblers are actually a winter bird for us here in the Susquehanna Valley.  They survive our winters by being good at eating many different types of food.  Their winter menu consists of a wide variety of fruit, insects, tree sap, and seeds.

Fruit may be the most important winter food for Butter-butts.  They are the only species of warbler that can digest the waxy fruit of bayberries and wax myrtles, which allows them to live in winter as far north as Nova Scotia.  In fact, the original name for the Yellow-rumped Warbler was Myrtle Warbler.  Other favorite native fruits include red cedar, Virginia creeper, poison ivy, and dogwood.  They also visit bird feeders, especially for Bark Butter, Bark Butter Bits, and suet.