Townsend's warbler

Townsend's warbler (Setophaga townsendi) is a small songbird of the New World warbler family.

Taxonomy
Townsend's warbler was formally described in 1837 by the American naturalist John Kirk Townsend under the binomial name Sylvia townsendi. The type locality is Fort Vancouver on the Columbia River in the state of Washington. After the merger of the genera Dendroica and Setophaga, Townsend's warbler is now placed in the genus Setophaga that was introduced by the English naturalist William Swainson in 1827. The species is monotypic: no subspecies are recognised.

Description
Townsend's warbler has a yellow face with a black stripe across its cheeks extending into an ear patch, a thin pointed bill, two white wing bars, olive upperparts with black streaks on their backs and flanks, and a white belly. Adult males have a black cap, black throat and yellow lower breast; females have a dark cap and a yellow throat. Immature birds are similar to females with a dark green cap and cheeks.

Life history
Their breeding habitats are coniferous forests with large trees on the northwestern coast of North America. Their nests are shallow cups built with grass and lined with moss. These nests are usually placed atop a branch in a conifer. The female lays 4 to 5 brown-speckled white eggs.

This bird is closely related to the hermit warbler, and the two species interbreed where their ranges overlap.

Birds from Haida Gwaii migrate short distances further south on the Pacific coast. Other birds winter in Mexico, Central America, and the south-western United States.

They forage actively in the higher branches, often gleaning insects from foliage and sometimes hovering or catching insects in flight. They mainly eat insects and spiders and seeds. Outside of the nesting season, these birds forage in mixed flocks. In winter, they also eat berries and plant nectar, and honeydew directly from the anus of scale insects.

The song of the male bird is a buzzed zee-zee-zee-bzz-zee or weazy weazy weazy weazy twea, somewhat similar to that of its eastern relative, the black-throated green warbler. The call is a sharp tup.

This bird was named after the American ornithologist, John Kirk Townsend. Although Townsend is also credited with first describing this bird, he used a name chosen by Thomas Nuttall, who was travelling with him, and so sidestepped the convention against naming a species after oneself.

Books

 * Wright, A. L., G. D. Hayward, S. M. Matsouka, and P. H. Hayward. 1998. Townsend’s Warbler (Dendroica townsendi). In The Birds of North America, No. 333 (A. Poole and F. Gill, eds.). The Birds of North America, Inc., Philadelphia, PA.

Thesis

 * Pearson SF. Ph.D. (1997). Behavioral and ecological tests of four models explaining narrow hybrid zones between hermit and Townsend's warblers. University of Washington, United States, Washington.

Articles
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 * Catherine ES & Sievert R. (2000). A phenotypic test of Haldane's rule in an avian hybrid zone. The Auk. vol 117, no 3. p. 578.
 * Deviche P, Greiner EC & Manteca X. (2001). Interspecific variability of prevalence in blood parasites of adult passerine birds during the breeding season in Alaska. Journal of Wildlife Diseases. vol 37, no 1. p. 28-35.
 * Greenberg R, Caballero CM & Bichier P. (1993). Defense of homopteran honeydew by birds in the Mexican highlands and other warm temperate forests. Oikos. vol 68, no 3. p. 519-524.
 * Jackson WM, Wood CS & Rohwer S. (1992). Age-Specific Plumage Characters and Annual Molt Schedules of Hermit Warblers and Townsend's Warblers. The Condor. vol 94, no 2. p. 490.
 * Kissling ML & Garton EO. (2006). Estimating detection probability and density from point-count surveys: A combination of distance and double-observer sampling. Auk. vol 123, no 3. p. 735-752.
 * Mannan RW, Hale BS & Morrison ML. (1983). Observations of Nesting Townsends Warblers Dendroica-Townsendi in Northeastern Oregon USA. Murrelet. vol 64, no 1. p. 23-25.
 * Mannan RW & Meslow EC. (1984). Bird Populations and Vegetation Characteristics in Managed and Old-Growth Forests Northeastern Oregon USA. Journal of Wildlife Management. vol 48, no 4. p. 1219-1238.
 * Manuwal DA. (1991). Spring Bird Communities in the Southern Washington Cascade Range USA. U S Forest Service General Technical Report PNW. vol 285, p. 161-175.
 * Matsuoka SM, Handel CM & Roby DD. (1997). Nesting ecology of Townsend's Warblers in relation to habitat characteristics in a mature boreal forest. Condor. vol 99, no 2. p. 271-281.
 * Matsuoka SM, Handel CM, Roby DD & Thomas DL. (1997). The relative importance of nesting and foraging sites in selection of breeding territories by Townsend's warblers. Auk. vol 114, no 4. p. 657-667.
 * Mizrahi DS & Wagner SJ. (1996). Georgia's second state record for Townsend's warbler. Oriole. vol 61, no 4. p. 81-82.
 * Morrison ML. (1983). Analysis of Geographic Variation in the Townsends Warbler Dendroica-Townsendi. Condor. vol 85, no 4. p. 385-391.
 * Owen-Ashley NT & Butler LK. (2004). Androgens, interspecific competition and species replacement in hybridizing warblers. Proceedings of the Royal Society Biological Sciences Series B. p. 6) S498-S500, December 497, 2004.
 * Pearson SF. (2000). Behavioral asymmetries in a moving hybrid zone. Behav Ecol. vol 11, no 1. p. 84-92.
 * Pearson SF & Manuwal DA. (2000). Influence of niche overlap and territoriality on hybridization between Hermit Warblers and Townsend's Warblers. Auk. vol 117, no 1. p. 175-183.
 * Pearson SF & Rohwer S. (2000). Asymmetries in male aggression across an avian hybrid zone. Behav Ecol. vol 11, no 1. p. 93-101.
 * Rappole JH, King DI & Barrow WC Jr. (1999). Winter ecology of the endangered Golden-cheeked Warbler. Condor. vol 101, no 4. p. 762-770.
 * Rohwer S. (1994). 2 NEW HYBRID DENDROICA WARBLERS AND NEW METHODOLOGY FOR INFERRING PARENTAL SPECIES. Auk. vol 111, no 2. p. 441-449.
 * Rohwer S. (1994). Two new hybrid Dendroica warblers and new methodology for inferring parental species. Auk. vol 111, no 2. p. 441-449.
 * Rohwer S. (2004). Using age ratios to infer survival and despotic breeding dispersal in hybridizing Warblers. Ecology. vol 85, no 2. p. 423-431.
 * Rohwer S, Bermingham E & Wood C. (2001). Plumage and mitochondrial DNA haplotype variation across a moving hybrid zone. Evolution. vol 55, no 2. p. 405-422.
 * Rohwer S, Wood C & Bermingham E. (2000). A new hybrid warbler (Dendroica nigrescens x D-occidentalis) and diagnosis of similar D-townsendi x D-occidentalis recombinants. Condor. vol 102, no 3. p. 713-718.
 * Sallabanks R, Haufler JB & Mehl CA. (2006). Influence of forest vegetation structure on avian community composition in west-central Idaho. Wildl Soc Bull. vol 34, no 4. p. 1079-1093.
 * Scott FP & Sievert R. (1998). Influence of breeding phenology and clutch size on hybridization between Hermit and Townsend's Warblers. The Auk. vol 115, no 3. p. 739.
 * Sievert R & Christopher W. (1998). Three hybrid zones between Hermit and Townsend's warblers in Washington and Oregon. The Auk. vol 115, no 2. p. 284.
 * Thompson LC. (1993). First Georgia record of a Townsend's Warbler. Oriole. vol 58, no 1-4. p. 1-3.
 * Tiedemann AR & Woodard PM. (2002). Multiresource effects of a stand-replacement prescribed fire in the Pinus contorta-Abies lasiocarpa vegetation zone of Central Washington. U S Forest Service Pacific Northwest Research Station General Technical Report PNW GTR. vol 535, p. 1-26.
 * Vidal RM, Macias-Caballero C & Duncan CD. (1994). The occurrence and ecology of the Golden-cheeked Warbler in the highlands of Northern Chiapas, Mexico. Condor. vol 96, no 3. p. 684-691.