Palm Warbler    Dendroica palmarum

Migratory Status: Neotropical migrant

PIF Population Estimate: 20 000 000

Percent of western hemisphere population breeding in boreal forest: 98%

BAM Effective Detection Radius (m) : 65.22

PIF Maximum Detection Distance (m) : 125

Canadian BBS Population trend: 2.6 n.s. (-0.3 to 5.5)

Life History

Palm Warblers are slim, active songbirds that are unusual among wood-warblers as the adult male and female are almost visually indistinguishable. In breeding plumage, adults are brownish-olive above and yellow below. They have a chestnut cap in summer, which becomes a dirty brownish-gray in fall and winter. The breast and flanks are subtlety streaked brown. Birds breeding in eastern North America are bright yellow underneath, while those in the west are dingier. Both populations have conspicuous rich yellow undertail-coverts. Palm Warblers frequently wag their tails when foraging on the ground or low shrubs.

The Palm Warbler is a true boreal species; almost the entire world’s population breeds in Canada’s northern forests. The summer range extends from the northeastern Yukon eastward to Newfoundland. Its preferred breeding habitats are bogs and open coniferous forests, typically with a high proportion of black spruce (Picea mariana) and tamarack (Larix laricina). The majority of Palm Warblers winter in the southeastern United States and the Caribbean, particularly near the coast. A few winter as far north as British Columbia in the west and Nova Scotia in the east. In tropical wintering areas, Palm Warblers sometime feed in palms, as their name implies, but more often forage in pastures, open forests, scrublands and residential areas. They sometimes form single-species flocks, but during migration, they frequently associate with other warblers, particularly the Yellow-rumped Warbler (Dendroica coronata).

Males sing from high branches and the tops of trees, frequently the tallest conifer in a forest stand. The song is a long, flat trill, easily confused with that of a Chipping Sparrow (Spizella passerina) or Dark-eyed Junco (Junco hyemalis). During the breeding season, males sing from dawn until early afternoon, then spend the rest of the day quietly in the vicinity of the nest. Other vocalizations include a soft “tsip”, and a louder emphatic “chick”, the latter is often uttered as an alarm call.

Males are territorial, but rarely engage in aggressive encounters. They will briefly chase intruding males of their species as well as other species that utilise similar habitat. On the wintering grounds, they will at times defend foraging areas from other birds.

Reference(s)

Wilson, Jr., W. H. 1996. Palm Warbler (Dendroica palmarum), 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/238