

The female builds a cup-shaped nest of twigs, pine needles, and grasses lined with fur and mosses on a horizontal conifer branch. Yellow-rumped Warblers pair up at the beginning of each breeding season. Yellow-rumped Warbler in winter plumage by Paul Reeves Photography Shutterstock Other populations are found in similar, but higher-altitude, woodlands. Yellow-rumped Warblers are birds of coniferous and mixed forests an estimated 63 percent of their population breeds in Canada's boreal forest. They sometimes visit backyard feeders for seed, suet, and fruit. Its ability to digest the waxy coating of berries allows the Yellow-rumped Warbler to winter farther north than other warbler species. When insect food is scarce, the Yellow-rumped Warbler switches to fruit, including wax myrtle berries, which gave the bird one of its former names. Like Blackpoll and Cape May Warblers, Yellow-rumped Warblers feed heavily on spruce budworm during outbreaks. It gleans caterpillars, larvae, spiders, and other invertebrates from leaves, or zips out from perches like a flycatcher to nab aerial insects such as craneflies and gnats. (Audio of Yellow-rumped Warbler song by Frank Lambert, XC353483, accessible at Audio of Yellow-rumped Warbler call by Martin St-Michel, XC467698, accessible at Flexible Feederĭuring its breeding season, the Yellow-rumped Warbler is mainly insectivorous.

These are the distinctive and nonmigratory "Black-fronted" Warbler of northwestern Mexico and the "Goldman's" Warbler of Guatemala. Two of these subspecies, associated with the "Audubon's" group, are found further south. These two groups are further divided into five subspecies. The two groups hybridize where their ranges meet in southwestern Canada, and were combined into a single species in 1973, named the Yellow-rumped Warbler.

North America is home to two migratory Yellow-rumped Warbler groups that are sometimes considered separate species: the "Myrtle" Warbler of eastern and far-northwestern North America and the "Audubon's" Warbler of the West. This bird's species name, coronata, means crowned. Adults also have a yellow crown patch, most obvious in adult males. Birders affectionately refer to this species as "butter-butt," since its bright yellow rump is an eye-catching and diagnostic field mark throughout the year. The Yellow-rumped Warbler is one of the most widespread and well-known warblers in North America. Yellow-rumped Warbler range map, Birds of North America, maintained by the Cornell Lab of Ornithology
