The species comprises two distinct subspecies that may merit specific status.
"Yellow Palm Warbler" (S. p. hypochrysea) of the eastern third of the breeding range has brownish-olive upper parts and thoroughly yellow underparts with bold rufous breast and flank streaking. It migrates later in the fall than its western counterpart.
"Western Palm Warbler" (S. p. palmarum) inhabits the remaining western two-thirds of the breeding range. It has much less yellow below, with less colorful streaking, and cold grayish-brown upper parts.
Palm Warblers breed in open coniferous bogs and edge east of the Continental Divide, across Canada and the northeastern United States. Their nests take the form of an open cup, usually situated on or near the ground in an open area.
These birds migrate to the southeastern United States, the Yucatán Peninsula, islands of the Caribbean, and eastern Nicaragua south to Panama to winter. They are one of the earlier migrants to return to their breeding grounds in the spring, often completing their migration almost two months before most other warblers.
Palm Warblers forage on the ground much more than other warblers, sometimes flying to catch insects. These birds mainly eat insects and berries. Their constant tail bobbing is an identifying characteristic.
The song of this bird is a monotonous buzzy, trill. The call is a sharp chek.
Status and distribution
Palm Warbler has been recorded as a vagrant to Iceland.
- BirdLife International (2009). "Dendroica palmarum". IUCN Red List of Threatened Species. Version 2011.2. International Union for Conservation of Nature. http://www.iucnredlist.org/apps/redlist/details/106009117. Retrieved 31 May 2012. Database entry includes justification for why this species is of least concern
- "Palm Warbler". All About Birds. Cornell Laboratory of Ornithology. http://www.birds.cornell.edu/AllAboutBirds/BirdGuide/Palm_Warbler.html. Retrieved 2008-10-12.
- Þráinsson, Gunnlaugur (1997) Palm Warbler and Cerulean Warbler in Iceland - new to the Western Palearctic Birding World 10(10): 392-393