Birds
Yellow-Rumped Warbler
Setophaga coronata · also called myrtle warbler, Audubon's warbler
While most warblers have long since departed for warmer climates, a yellow-rumped warbler continues foraging through a cold northern winter, drawing sustenance from waxy bayberries that most of its warbler relatives simply cannot digest.
Overview
The yellow-rumped warbler, Setophaga coronata, is a widespread and abundant warbler that breeds in coniferous and mixed forest across Canada and the northern United States before wintering across a broad range farther south. Its unusual ability to digest waxy winter berries and its distinctive bright yellow rump patch make it one of the most successful and easily recognised warblers in North America.
A diet that stretches the winter map
While most warblers are forced south by the disappearance of insects, the yellow-rumped warbler’s rare ability to live on waxy berries lets it hold its ground considerably farther north, redrawing what a typical warbler’s winter range can look like.
Status
Least Concern — widespread and abundant across suitable forest breeding habitat and its broad wintering range throughout North America.
Yellow-Rumped Warbler: common questions
Why can the yellow-rumped warbler winter so much farther north than other warblers?
A yellow-rumped warbler can digest the waxy coating of bayberry and wax myrtle fruit, a food source most other warbler species cannot process, and this ability to switch to a fruit-based diet when insects become scarce lets the species winter considerably farther north than almost any other North American warbler.
Were the myrtle warbler and Audubon's warbler always considered the same species?
No, the yellow-rumped warbler exists as two recognisable forms, the myrtle warbler in the east and Audubon's warbler in the west, and the two were once classified as entirely separate species before genetic and hybridisation studies led to them being combined into a single species.
Why is the yellow-rumped warbler sometimes called the butter-butt?
A yellow-rumped warbler displays a bright yellow patch on the rump, visible even in the duller plumage worn outside the breeding season, a feature distinctive enough to give the species the informal birdwatcher nickname butter-butt.
Where does the yellow-rumped warbler live?
The yellow-rumped warbler breeds in coniferous and mixed forest across Canada and the northern United States, then winters across a broad range further south, including areas considerably farther north than most other wintering warblers can tolerate.