The Chestnut-sided Warbler (Dendroica pensylvanica) is a New World warbler. They breed in eastern North America and in southern Canada westwards to the Canadian Prairies. They also breed in the Great Lakes region and in the eastern USA.
These birds are migratory, wintering in Central America south to northern Colombia, with an unconfirmed sighting from as far south as Ecuador; they are also very rare vagrants to western Europe.
In the summer, male Chestnut-sided Warblers are unmistakable in appearance. They display dark-streaked gray backs, white faces, black eyestripes and greenish crowns. Their underparts are white, with chestnut flanks, and they also have two white wing bars. The adult females resemble washed-out versions of the summer male, and in particular, the females lack the strong head pattern, and also have less chestnut coloring on their flanks.
Non-breeding birds of both sexes have greenish heads, and greenish upperparts which are usually unstreaked. They also have unstreaked pale grey breasts. Their wing bars are always present in their plumages. Their lack of streaking helps to distinguish this species from the Blackpoll Warbler outside the breeding season.
The songs are whistled pleased, pleased, pleased to meecha lines. Their calls are harsh chips. Their cup-shaped nests are placed in a low bush, which is usually located in young deciduous woodland or scrub. These birds lay 3-5 eggs. Their species is frequently parasitized by cowbirds.
Chestnut-sided Warblers are insectivorous, but will include berries in their winter dietsE.g. those of Cymbopetalum mayanum (Annonaceae); such trees can be used to attract wintering birds into gardens and parks: Foster (2007). They forage actively in shrubs and small trees, and sometimes will attempt to catch insects in mid-air.
This bird's numbers have increased as second growth forest became more common in the east in the late 19th century; their numbers have declined slightly since then.
Database entry includes justification for why this species is of least concern
(1994): New World Warblers. Christopher Helm, London. ISBN 0-7136-3932-6
(2007): The potential of fruiting trees to enhance converted habitats for migrating birds in southern Mexico. Bird Conservation International 17(1): 45-61. PDF fulltext
(2004): New and noteworthy records of birds from the Sierra Nevada de Santa Marta region, north-eastern Colombia. Bull. B.O.C. 124(1): 38-51. PDF fulltext
Chestnut-sided Warbler videos, photos & sounds on the Internet Bird Collection
Chestnut-sided Warbler - Dendroica Pensylvanica - USGS Patuxent Bird Identification InfoCenter
Chestnut-sided Warbler Species Account - Cornell Lab of Ornithology
Chestnut-sided Warbler Information and Photos - South Dakota Birds and Birding
Chestnut-sided Warbler photo gallery VIREO
Chestnut-sided Warbler at Animal Diversity Web
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article Chestnut-sided Warbler