Yellow-rumped Warbler
Dendroica coronata

Migratory Status: Neotropical migrant

PIF Population Estimate: 130 000 000

Percent of western hemisphere population breeding in boreal forest: 63%

BAM Effective Detection Radius (m) : 64.13

PIF Maximum Detection Distance (m) : 125

Canadian BBS Population trend: -0.1 n.s. (-0.8 to 0.6)

Life History

The Yellow-rumped Warbler is Canada’s most abundant wood-warbler and one of the first warblers to arrive on its breeding grounds in the spring. It is divided into two subspecies groups that were once considered separate species – the Myrtle Warbler to the north and east, and the Audubon’s Warbler to the west. The species’ merge was based on genetic evidence and proof of interbreeding in a narrow zone between British Columbia and Alberta.

Breeding males are easily distinguished from other warblers with a yellow rump by having a white and black breast and belly, instead of yellow. Other identifying features are a yellow crown patch, yellow side patches on the breast, and black cheeks. The main difference between the two subgroups is throat colour. Yellow-rumped “Myrtle” Warblers have a white throat, while Yellow-rumped “Audubon’s” Warblers have a yellow throat.

This species can be found in many habitats, but it prefers coniferous or mixedwood forest and as such, the boreal forest provides a large portion of its breeding habitat in Canada. The breeding range extends from Alaska east all the way to Newfoundland. Along the west coast it continues south through the western states into Mexico and Guatemala, and in the east, the breeding range stops around the Great Lakes Region. The winter range of Yellow-rumped Warblers extends from Washington State along the Pacific coast, and Nova Scotia and northern Massachusetts along the Atlantic coast, down through the southern states into Mexico, Central America, and the Caribbean.

Unique to this warbler species is an ability to digest the wax in bayberries (Myrica spp.), which allows it to overwinter so far north along each coast. While insects make up a large portion of the Yellow-rumped Warbler’s breeding diet, in the non-breeding season fruit and berries become very important.

Reference(s)

Hunt, P. D., and D. J. Flaspohler. 1998. Yellow-rumped Warbler (Dendroica coronata), The Birds of North America Online, . A. Poole, Ed. Ithaca: Cornell Laboratory of Ornithology; Retrieved from The Birds of North America Online database: http://bna.birds.cornell.edu/bna/species/376.