Mourning Warbler    Oporornis philadelphia

Migratory Status: Neotropical migrant

PIF Population Estimate: 7 000 000

Percent of western hemisphere population breeding in boreal forest: 75%

BAM Effective Detection Radius (m) : 72.16

PIF Maximum Detection Distance (m) : 125

Canadian BBS Population trend: -1.8 (-2.5 to -1.2)

Life History

The Mourning Warbler is a secretive understorey bird found in mixed woods and secondary forests of the boreal forest. Skulking in dense undergrowth and foraging near the ground makes it a hard warbler to see during the breeding season. The breeding range for this species extends from north-eastern British Columbia east into Newfoundland and Labrador. To the south, it extends into the United States, ranging from North Dakota to Pennsylvania and West Virginia. The Mourning Warbler winter range stretches from Nicaragua south along the Caribbean slope of Central America into the north western countries of South America.

Although difficult to spot, males in definitive alternate plumage offer flashes of yellow and a cheery “churry churry churry churry chorry chorry” song around bogs, clearings, and road sides in the summer. When spotted, breeding males can be identified by their grey hood (head and throat), black spot between hood and breast, bright yellow belly and vent, and olive-yellow back. Females are duller in appearance and lack the black on their throat.

Mourning Warblers are insectivores on their breeding grounds, foraging within 1-2 m of the ground by gleaning insects off branches in thickets. Like many other wood warblers, they are heavily frugivorous on their wintering grounds, becoming important seed dispersers in early successional and disturbed habitats in the neotropics.

Reference(s)

Pitocchelli, J. 1993. Mourning Warbler (Oporornis philadelphia), 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/072