Yellow-rumped Warbler

Look for

A small, streaky, gray-brown warbler with a bright yellow rump patch that flashes like a signal flag in flight. Winter birds are drab; spring birds show sharp black and yellow patches.

Size: ~5.5" — small warbler.

Listen for

• Call: a dry, sharp "check!" — constantly given as flocks move through shrubs.
• Song: a soft warbling trill (rarely heard in Memphis — they sing on northern breeding grounds).

Where in Memphis

The most abundant winter warbler in the South. Yellow-rumps are everywhere — woodlands, backyards, parks, shrubby edges — October through April.

Behavior

• The warbler that eats berries. Almost uniquely among warblers, they can digest wax-coated berries (juniper, bayberry, poison ivy) — which lets them winter much farther north than other warblers.
• Flycatch in winter — they sally out from perches to catch gnats and midges on warm days.
• Travel in loose flocks of 10–30 birds, often with kinglets and chickadees.

Story

"Butter-butt"

Universal affectionate birder nickname. The yellow rump is unmistakable — the first field mark every beginning winter birder learns.

The Myrtle Warbler split (and un-split)

For decades, "Myrtle Warbler" (Eastern) and "Audubon's Warbler" (Western) were considered separate species. In 1973 they were lumped into one "Yellow-rumped Warbler." Ongoing research suggests they may get split again — stay tuned. Memphis only gets the Myrtle form.

The poison-ivy warbler

Yellow-rumps are one of the few birds that eat poison-ivy berries in winter. The seeds pass through and get dispersed — Yellow-rumps are one reason poison ivy is so widespread in Southern woodlands.

Fun facts

• Memphis Yellow-rumps bred in Canadian boreal forest last summer.
• They can survive sub-freezing temperatures by digesting wax — other warblers would starve.
• Oldest known wild Yellow-rumped Warbler: 9+ years.
• In a big winter, Memphis can host tens of thousands of Yellow-rumps.