Blackburnian warbler

The Blackburnian warbler (Setophaga fusca) is a small New World warbler. They breed in eastern North America, from southern Canada, westwards to the southern Canadian Prairies, the Great Lakes region and New England, to North Carolina. They are migratory, wintering in southern Central America and South America, and are very rare vagrants to western Europe. The common name honors the English botanist Anna Blackburne.

Taxonomy

The Blackburnian warbler was formally described in 1776 by the German zoologist Philipp Statius Müller under the binomial name Motacilla fusca.<ref>Template:Cite book</ref><ref name=paynter>Template:Cite book</ref> The specific epithet is Latin meaning "dusky", "black" or "brown".<ref>Template:Cite web</ref> Müller based his account on a handcoloured plate of the "Figuier étranger" that had been engraved by François-Nicolas Martinet to accommpany the Comte de Buffon's multivolume work Histoire Naturelle des Oiseaux.<ref name=paynter/><ref>Template:Cite book</ref> The type location is French Guiana.<ref name=paynter/><ref>Template:Cite book</ref><ref>Template:Cite book</ref> The Blackburnian warbler is now placed in the genus Setophaga that was introduced by the English naturalist William Swainson in 1827.<ref name=ioc>Template:Cite web</ref> The genus name Setophaga combines the Ancient Greek σης/sēs, σητος/sētos meaning "moth" with -φαγος/-phagos meaning "-eating".<ref>Template:Cite web</ref> The species is monotypic: no subspecies are recognised.<ref name=ioc/> The common name was introduced in 1785 by the Welsh naturalist Thomas Pennant to honour Anna Blackburne, an English botanist.<ref>Template:Cite journal</ref><ref>Template:Cite book</ref>

Description

Blackburnian warblers are small passerines and average-sized wood-warblers. They measure around Template:Convert long, with a Template:Convert wingspan, and weigh Template:Convert. The average mass of an adult bird is Template:Convert, although is slightly higher in fall due to fat reserves, averaging Template:Convert.<ref>Graber, J. W., R. R. Graber, and E. L. Kirk. 1983. Illinois birds: wood warblers. Biological Notes No. 118. III. Nat. Hist. Surv. Urbana, IL.</ref> Among standard measurements, the wing chord is Template:Convert, the tail is Template:Convert, the bill is Template:Convert and the tarsus is Template:Convert.<ref>Template:Cite book</ref> In summer, male Blackburnian warblers display dark gray backs and double white wing bars, with yellowish rumps and dark brown crowns. The underparts of these birds are white and are tinged with yellow and streaked black. The head is strongly patterned in yellow and black, with a flaming-orange throat. It is the only North American warbler with this striking plumage. Other plumages, including the fall male and adult female, are washed-out versions of the summer male, and in particular, lack the bright colors and strong head pattern. The Blackburnian warbler is practically unmistakable if seen well, even the female due to her dull-yellow supercilium, contrasting with greyish cheeks and yellow throat contrasting with the dark streaky sides and back. The only other wood-warbler with an orange throat is the flame-throated warbler of Central America, which is very distinctive, lacking the contrasting blackish streaking about the head and whitish underside of a male Blackburnian.<ref>Dunn, J. and K. Garrett. 1997. A field guide to warblers of North America. Houghton Mifflin, Boston.</ref> Basic plumages show weaker yellows and gray in place of black in the breeding male.

Blackburnian warblers' songs are a simple series of high swi notes, which often ascend in pitch. Transliterations have included zip zip zip zip zip zip zip zip, titititi tseeeeee or teetsa teetsa teetsa teetsa.<ref>Ficken, M. S. and R. W. Ficken. 1962. The comparative ethology of the wood warblers: a review. Living Bird 1:103-122.</ref> Their call is a high sip. Genetic research has shown that their close living relative is the bay-breasted warbler, the latter species perhaps specialized to forage in the same coniferous trees at lower levels.<ref>Lovette, I. J. and E. Bermingham. 1999. Explosive speciation in the New World Dendroica warblers. Proc. R. Soc. London B 266:1629-1636.</ref> Hybridization in the wild has been recorded once each with a bay-breasted warbler (in West Virginia), with a black-and-white warbler (in Pennsylvania), and possibly a wintering hybrid with a Kirtland's warbler (in Hispaniola).<ref>Hurley, G. F. and J. W. Jones II. 1983. A presumed mixed Bay-breasted x Blackburnian Warbler nesting in West Virginia. Redstart 50:108-111.</ref><ref>Parkes, K. C. 1983. Three additional hybrid combinations in North American birds. Abstract of paper presented at the 101st stated meeting of the American Ornithologists' Union.</ref><ref>Latta, S. C. and K. C. Parkes. 2001. A possible Dendroica kirtlandii hybrid from Hispaniola. Wilson Bull. 113:378-383.</ref>

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  male, New York
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  1st winter, Costa Rica

Ecology

Blackburnian warblers are solitary during winter, highly territorial on their breeding grounds, and do not mix with other passerine species outside of the migratory period. However, during migration, they often join local mixed foraging flocks of species such as chickadees, kinglets, and nuthatches. Similarly, in the tropics, they were found to be fairly social while engaging in migration but solitary from other passerines while wintering.<ref name= Bent>Bent, A. C. 1953. Life histories of North American wood warblers. U.S. Natl. Mus. Bull. 203.</ref> These birds are basically insectivorous but will include berries in their diets in wintertime. They usually forage by searching for insects or spiders in treetops. Their breeding season diet is dominated by the larvae of Lepidoptera, i.e. moths and butterflies.<ref>Morse, D. H. 1976. Variables determining the density and territory site of breeding spruce-woods warblers. Ecology 57:290-301.</ref> They may help control the spruce budworm (often considered a harmful pest) when breakouts occur, at the local if not at epidemic level.<ref>Crawford, H. S., R. W. Titterington, and D. T. Jennings. 1983. Bird predation and spruce budworm populations. J. For. 81:433-435.</ref> In one study from Ontario, 98% of the diet was made of insects, the remaining 2% being spiders.<ref>Kendeigh, S. C. 1947. Bird population studies in the coniferous forest biome during a spruce budworm outbreak. Dept. Lands Forests, Ontario, Canada, Biol. Bull. 1:1-100.</ref> Among the migratory Setophaga warblers, it is considered one of the specialists at foraging in the micro-habitat of the tree's top canopy.<ref>Morse, D. H. 1968. A quantitative study of foraging of male and female spruce woods warblers. Ecology 49:779-784.</ref>

The breeding habitats of these birds are mature coniferous woodlands, the central part of their breeding range being in the southeastern portion of Canada's boreal forest. However, their distribution as a breeding species continues broadly down much of New England and the Appalachian Mountains, from New York to northernmost Georgia, in elevated mixed woodlands, especially ones containing spruce and hemlocks.<ref name= Morse2>Morse, Douglass H. 2004. Blackburnian Warbler (Setophaga fusca), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology.</ref> Hemlocks in particular are most likely to host Blackburnian warblers in mixed forests.<ref>Kendeigh, S. C. 1945b. Nesting behavior of wood warblers. Wilson Bull. 57:145-164.</ref> It typically winters in tropical montane forests, from roughly Template:Convert, mainly from Colombia to Peru, more sporadically in Panama and the Amazon region.<ref>Hilty, S. L. and W. L. Brown. 1986. A guide to the birds of Colombia. Princeton Univ. Press, Princeton, NJ.</ref><ref>Ridgely, R. S. and J. A. Gwynne. 1989. A guide to the birds of Panama. 2nd ed. Princeton Univ. Press, Princeton, NJ.</ref><ref>Stotz, D. F., R. O. Bierregaard, M. Cohn-Haft, P. Petermann, J. Smith, A. Whittaker, and S. V. Wilson. 1992. The status of North American migrants in central Amazonian Brazil. Condor 94:608-621.</ref>

Blackburnian warblers begin their first clutches in mid-May to early June in the contiguous United States and about 1 to 2 weeks later in Quebec.<ref name= Bent/> This species builds a nest consisting of an open cup of twigs, bark, plant fibers, and rootlets held to a branch with a spider web and lined with lichens, moss, hair, and dead pine needles, that is placed near the end of a branch. Although typically only laying one brood per year, if a nest is destroyed they are capable of producing a second or even third brood.<ref>Morse, D. H. 1989. American warblers: an ecological and behavioral perspective. Harvard Univ. Press, Cambridge, MA.</ref> Three to five whitish eggs are laid in its nest which is usually placed Template:Convert above the ground, on a horizontal branch.<ref>Template:Cite web</ref> Nests usually constructed outwardly with twigs, bark, plant fibers, and rootlets; lined with lichens, mosses, fine grasses, hair, dead pine needles, and even occasionally such exotic substances as string, willow cotton, horsehair, and cattail down.<ref name= Morse2/> Only the female broods and spends about 80% day actively brooding, with the male usually helping bring food to the nest.<ref>Lawrence, L. de K. 1953. Notes on the nesting behavior of the Blackburnian Warbler. Wilson Bull. 65:135-144.</ref> Among warblers, they are relatively rarely parasitized at the nest by brown-headed cowbirds, most likely due to the cowbirds' lack of success in dense pine-dominated forests.<ref>Peck, G. K. and R. D. James. 1989. Breeding birds of Ontario: nidiology and distribution. Royal Ont. Museum, Toronto.</ref><ref>Merriam, C. H. 1885. Nest and eggs of the Blackburnian Warbler. Auk 2:103.</ref> Blue jays and American red squirrels have been verified to prey on nestlings and new fledglings, while a merlin was recorded killing a brooding adult female. Sharp-shinned hawks and Cooper's hawks are likely, but not confirmed, predators of adult Blackburnian warblers.<ref name= Morse2/> By far the greatest threat faced by this species is the destruction of forest habitat, which some predict could cause the Blackburnian warbler to lose up to more than 30% of its wintering or breeding habitat.<ref>Webb, W. L., D. F. Behrend, and B. Saisorn. 1983. Effect of logging on songbird populations in a northern hardwood forest. Wildl. Monogr. 55:1-35.</ref><ref>Diamond, A. W. 1991. Assessment of the risks from tropical deforestation to Canadian songbirds. Trans. NA Wildl. Nat. Res. Conf. 56:177-194.</ref> However, currently, this species continues to occur over a large range and can appear in stable numbers where habitat is appropriate.<ref name= Morse2/>

External links

• Template:InternetBirdCollection
• Blackburnian warbler species profile - The Nature Conservancy
• Blackburnian warbler species account - Cornell Lab of Ornithology
• Blackburnian warbler - Dendroica fusca - USGS Patuxent Bird Identification InfoCenter
• Template:Usurped (for Cuba, Grenada) with Range Map at bird-stamps.org
• Template:VIREO