A medium-sized (5 inches) wood warbler, the male Blackpoll Warbler in summer is most easily identified by its gray body, streaked back and flanks, and black head with prominent white cheek patches. Female Blackpoll Warblers are dull gray overall with faint white eye-stripes. In fall and winter, both sexes become dull green-gray on the back and pale tan below. The Blackpoll Warbler primarily breeds across Alaska and north-central Canada. Smaller numbers breed in southeastern Canada, and isolated breeding populations exist in the mountains of New England and New York. The Blackpoll Warbler is a long-distance migrant, wintering in northern South America. Blackpoll Warblers breed in northern and high-mountain evergreen forests, particularly in areas where Black Spruce (Picea mariana) occurs. In winter, this species may be found primarily in humid tropical forests. Blackpoll Warblers mainly eat small invertebrates, including insects and spiders, although this species may eat fruits or berries while on migration. In appropriate habitat, Blackpoll Warblers may be observed foraging for food located on leaves, needles, and branches in the forest canopy. Birdwatchers may also listen for this species’ song, a high “zi” note repeated several times in quick succession. Blackpoll Warblers are primarily active during the day, but, like many migratory songbirds, this species migrates at night.
- Hunt, Pamela D. and Bonita C. Eliason. 1999. Blackpoll Warbler (Setophaga striata), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online: http://bna.birds.cornell.edu/bna/species/431
- Peterson, Roger Tory. Birds of Eastern and Central North America. Boston: Houghton Mifflin, 1980. Print.
- eBird Range Map - Blackpoll Warbler. eBird. Cornell Lab of Ornithology, N.d. Web. 20 July 2012. http://ebird.org/ebird/map/bkpwar.
- Dendroica striata. Xeno-canto. Xeno-canto Foundation, n.d. Web. 20 July 2012. http://xeno-canto.org/browse.php?query=Dendroica+striata.
- Blackpoll Warbler (Dendroica striata). The Internet Bird Collection. Lynx Edicions, n.d. Web. 20 July 2012. http://ibc.lynxeds.com/species/blackpoll-warbler-dendroica-striata.
occurs (regularly, as a native taxon) in multiple nations
Regularity: Regularly occurring
Type of Residency: Breeding
Regularity: Regularly occurring
Type of Residency: Breeding
Global Range: Breeding range extens from western and north-central Alaska and northwestern Canada (Mackenzie Delta) to northern Labrador and Newfoundland, and south to southern Alaska, south-central British Columbia, northern Saskatchewan, eastern New York, northern New England, and Nova Scotia. During the northern winter, this warbler occurs primarily in the Amazon basin in Colombia, Venezuela, Ecuador, Peru, Brazil, and Bolivia, and has been found several times in southern South America, where the species is perhaps common locally in southeastern Brazil (Ridgely and Tudor 1989). This species is an autumn transient in Bermuda, Bahamas, eastern Greater Antilles, and throughout the Lesser Antilles; spring transient in western Greater Antilles and Bahamas; casual in Central America (Stiles and Skutch 1989).
- Clements, J. F., T. S. Schulenberg, M. J. Iliff, B.L. Sullivan, C. L. Wood, and D. Roberson. 2012. The eBird/Clements checklist of birds of the world: Version 6.7. Downloaded from http://www.birds.cornell.edu/clementschecklist/downloadable-clements-checklist
Length: 14 cm
Weight: 13 grams
Catalog Number: USNM 231288
Collection: Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Birds
Sex/Stage: Male; Adult
Preparation: Skin: Whole
Collector(s): G. Hanna
Year Collected: 1911
Locality: Nushagak, Nushagak Bay, Dillingham Census Area, Alaska, United States, North America
- Type: Burleigh & Peters. June 16, 1948. Proc. Biol. Soc. Washington. 61: 119.
Comments: Cool, wet boreal coniferous forest (primarily spruce), usually dominated by low trees; locally also mixed second growth, regenerating burns, peatlands, and alder thickets (AOU 1998). In migration in various forest, forest border, woodland, scrub, and brushy habitats (AOU 1983), clearings with scattered trees. In winter, mostly (exclusively?) on islands in and vegetation surrounding major rivers.
Nests usually are well hidden in small trees, to about 3 m above ground. Adults usually return to previously used breeding sites (Eliason 1986).
Habitat and Ecology
Non-Migrant: No. All populations of this species make significant seasonal migrations.
Locally Migrant: No. No populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).
Locally Migrant: Yes. At least some populations of this species make annual migrations of over 200 km.
Late migrant in spring in Atlantic states; moves through northeast May-June (Terres 1980). Migrates from eastern North America to northern South America, nonstop or through West Indies, with most apparently not going through the southeastern U.S. before going to South America (McNair and Post 1993). Fairly common in fall in Puerto Rico, rare in spring (Raffaele 1983, Murray 1989). Present in South America mostly September-April, occasionally to May (Ridgely and Tudor 1989).
Comments: Eats various small insects and spiders gleaned from leaves and twigs of trees; also flycatches and eats some small fruits (Terres 1980).
Comments: Global abundance estimated at 21,000,000 birds (Rich et al. 2004).
Life History and Behavior
Lifespan, longevity, and ageing
Eggs laid June-July. Clutch size 3-5 (usually 4-5). Incubation at least 11 days, by female. Young tended by both sexes, leave nest at 10-12 days. (Terres 1980, Harrison 1978). Some males bigamous (Eliason 1986).
Molecular Biology and Genetics
Barcode data: Dendroica striata
There are 22 barcode sequences available from BOLD and GenBank. Below is a sequence of the barcode region Cytochrome oxidase subunit 1 (COI or COX1) from a member of the species. See the BOLD taxonomy browser for more complete information about this specimen and other sequences.
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Download FASTA File
Statistics of barcoding coverage: Dendroica striata
Public Records: 22
Specimens with Barcodes: 24
Species With Barcodes: 1
National NatureServe Conservation Status
Rounded National Status Rank: N5B - Secure
Rounded National Status Rank: N5B - Secure
NatureServe Conservation Status
Rounded Global Status Rank: G5 - Secure
Reasons: Large breeding range in North America; numerous; secure.
IUCN Red List Assessment
Red List Category
Red List Criteria
Global Long Term Trend: Increase of 10-25% to decline of 30%
Comments: Breeding Bird Survey (BBS) data indicted an Increasing trend from 1966 to 1980 (Sauer et al. 2005). Since 1980, North American BBS data indicate that this species has suffered the steepest long-term decline of any neotropical-nearctic migrant landbird (9.6 percent per year, P< 0.00, n = 59), with population declines of over 50 percent and 90 percent across breeding ranges in Alaska and Canada, respectively (Sauer et al. 2004, 2005). When the entire BBS data set is considered, the long-term trend is a nonsignificant decrease of 2.6 percent per year (1966-2005). Only in New Brunswick is this long-term trend significant (6.3% per year, P< 0.00, n = 8; Hunt and Eliason 1999, Sauer et al. 2005).
Comments: Threats include habitat loss at breeding and nonbreeding areas, in-flight collisions during migration, mortality during migration associated with increased storm frequency/severity, and climate change related habitat loss of favored riparian and bog habitats.
Habitat loss: Breeding densities declined in 20-meter riparian buffers after the surrounding habitat was removed by clearcutting in the Canadian boreal forest (Darveau et al. 1995). Degradation of red spruce and subalpine spruce-fir forests from acid rain in the northeastern United States and southeastern Canada may adversely affect this species (Darveau et al. 1995, Hunt and Eliason 1999, Moegenburg and Greenberg 2004). Deforestation on wintering grounds in lowland Amazonia may also impact the species; blackpoll warblers were considered one of the 12 species most vulnerable to extinction due to tropical deforestation (Petit et al. 1993, Petit et al. 1995).
Collisions: This species commonly collides with towers during migration (e.g., communication, wind turbines, buildings), presumably due to their attraction to lights and disorientation during night migration (Bent 1953, Ogden 1996, Hunt and Eliason 1999). Hundreds to thousands of deaths have been reported at single locations over one season (Ogden 1996). In a study of tower kills in the United States since 1949, blackpoll warblers were the seventh most commonly killed bird (of 230 reported species) with 6,304 documented dead at 32 towers (Shire et al. 2000). Of concern is the marked increase in the number of towers constructed in the United States and Canada following the growth of the cell phone industry and wind energy development (Shire et al. 2000, ADFG 2005).
Climate change: Rates of survival and productivity of trans-oceanic migrants are associated with El Niño and North Atlantic Oscillation events (Nott et al. 2002). Abundance of breeding blackpoll warblers from 1967 to 1996 was negatively correlated with the frequency and severity of storms over the Atlantic Ocean and Gulf of Mexico during fall migration the previous year (Butler 2000). During this long, transoceanic flight (the longest of any North American warbler), birds may be particularly susceptible to mortality, which has been found to account for 90% of annual mortality in congeneric Black-throated Blue warbler Dendroica caerulescens (Sillett and Holmes 2002). Climate change may reduce riparian and bog habitats favored by this species through permafrost degradation and drying (ADFG 2005).
Biological Research Needs: Research needs include the following: evaluate potential threats on both breeding and wintering grounds, and assess their contribution to the observed decline; examine the role of Atlantic storm frequency on mortality during migration (Butler 2000); develop ways to reduce the frequency of tower strikes during migration (e.g., study the attractiveness of different light types to this species; Shire et al. 2000, Jones and Francis 2003); obtain better information on habitat use at migration stopover sites and on wintering grounds.
The blackpoll warbler (Setophaga striata) is a New World warbler. Breeding males are mostly black and white. They have a prominent black cap, white cheeks and white wing bars. The blackpoll breeds in northern North America, from Alaska, through most of Canada, and into the Great Lakes region and New England.
They are a common migrant through much of North America move down to winter in northwestern South America. They are rare vagrants to western Europe, although their northerly range and long-distance migration make them one of the more frequent transatlantic passerine wanderers.
The blackpoll warbler is a fairly small bird which attains the weight of a ball point pen. However, it is one of the larger of the diverse Setophaga genus (formerly Dendroica). In the species, body length can vary from 12.5 to 15 cm (4.9 to 5.9 in) and wingspan can range from 20 to 25 cm (7.9 to 9.8 in). Body mass can vary from 9.7 to 21 g (0.34 to 0.74 oz), with an average bird anywhere between 12 and 15 g (0.42 and 0.53 oz). Among standard measurements, the wing chord is 6.6 to 8 cm (2.6 to 3.1 in), the tail is 4.5 to 5.4 cm (1.8 to 2.1 in), the bill is 0.8 to 1.2 cm (0.31 to 0.47 in) and the tarsus is 1.8 to 2 cm (0.71 to 0.79 in). The summer male blackpoll warblers have dark-streaked brown backs, white faces and black crowns. Their underparts are white with black streaks, and they display two white wing bars. The adult females essentially resemble washed-out versions of the summer males, and in particular, the females lack the strong head patterns, and their crowns and faces are shades of gray. Another outstanding physical characteristic of the species are the bright orange, pink legs.
Non-breeding birds of this species have greenish heads, dark-streaked greenish upperparts and yellowish breasts, with the yellow extending to the belly in young birds. Their wing bars are always present.
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In the southern portion of their breeding range, blackpoll warblers can be found on the higher elevations of mountains in woodland or brushy areas. They also spend their summers on the wooded coastal islands of Maine and the Maritime Provinces. Farther north they have been reported throughout the boreal coniferous forest. Blackpolls breed nearer to the tundra than any other warbler.
Although fairly large for a warbler, blackpoll warblers are fairly easy to miss because of their relatively inactive foraging style and tendency to perch in dense foliage near the canopy of the trees. They are more often heard than seen, though their song is one of the highest pitched known. Their songs are simple repetitions of high tsi notes. Their calls are thin sits.
Foraging and diet
The blackpoll has a deliberate feeding style with occasional flitting, hovering and hawking around branches. They birds are primarily insectivorous. The species appears to be quite a generalist, preying on a great diversity of adult and larval insects and spiders. Documented insect prey for the species includes lice, locusts, cankerworms, mosquitoes, webworms, ants, termites, gnats, aphids and sawflies. It has been suggested that this species may be a spruce budworm specialist, but there is no obvious connection between population trends of the two species. The blackpoll will opt for berries in migration and during winter. They often forage high in trees, and sometimes catch insects while in flight.
Their breeding habitats are coniferous woodlands, especially those in which spruce trees grow. These birds' breeding ranges extends to the taiga. Blackpoll warblers commonly nest in a relatively low site which can be found in a conifer, and they lay 3–9 eggs in a cup-shaped nest, though most nest usually contain less than 5 eggs. The eggs are incubated for around 12 days and the young leave the nest when they are only 10 days old, before they can fly well. They are feed by the parents for a total of around two weeks. Mated females usually begin second nests right away and leave post-fledging parental duties to their mates. The high incidence of double brooding, coupled with (and partly a function of) low nest predation and parasitism rates, results in high annual productivity for this species.
Blackpoll warblers have the longest migration of any species of New World warbler. This is likely the reason that are one of the later warblers to appear in spring migration, with a relatively prolonged movement through North America anytime from early May to mid-June. In spring, the peak of the species' migratory movement in late May, when most warblers are on their breeding grounds. They usually passage through in August and September during fall migration, a more typical timing.
Baird describes the fall migration of the blackpoll. From their breeding grounds across the northern latitudes, they converge on the Northeastern United States south to Virginia starting in mid-August. Part of the fall migratory route of the blackpoll warbler is over the Atlantic Ocean from the northeastern United States to Puerto Rico, the Lesser Antilles, or northern South America. To accomplish this flight, the blackpoll warbler nearly doubles its body mass in staging areas and takes advantage of a shift in prevailing wind direction to direct it to its destination. When they fly southward over the Atlantic they burn, according to Baird, .08 grams of fat every hour. This route averages 3,000 km (1,900 mi) over water, requiring a potentially nonstop flight of around 72 to 88 hours. They travel at a speed of about 27 mph (43 km/h). Blackpolls can weigh more than 20 g (0.71 oz) when they leave the United States and lose 4 or more grams by the time they reach South America. Some of the blackpolls land in Bermuda before going on. Some birds, often with lower body weights, don't make it.
Scientific studies and discussion
The blackpoll warbler's transoceanic flight has been the subject of over twenty-five scientific studies. Sources of data include radar observations, bird banding and weights taken, dead birds recovered from field sites and fatal obstacles.
Island stopovers at Bermuda and other places have been cited as evidence of migratory pathways. Baird's conclusion, stated above, differed from Cooke (1904, 1915) and Murray (1965, 1989). Cooke and Murray contended that the blackpoll warbler migrates to South America along the mainland of southeastern North America. Baird, Nisbet and others argued that most blackpoll warblers fly directly from northeastern North America over the Atlantic Ocean to their winter range. They used data from nocturnal accidents, banding stations and sightings to state that blackpoll warblers are rare autumn migrants south of Cape Hatteras, North Carolina, whereas north of Hatteras they are common. Those holding to a direct oceanic pathway pointed to this evidence to support their hypothesis.
- BirdLife International (2012). "Dendroica striata". IUCN Red List of Threatened Species. Version 2013.2. International Union for Conservation of Nature. Retrieved 26 November 2013.
- Baird, p. 65
- Curson, Jon; Quinn, David and Beadle, David (1994). New World Warblers: An Identification Guide, ISBN 0-7136-3932-6.
- Morse, Douglas H. (1979). "Habitat Use by the Blackpoll Warbler". Wilson Bulletin 91 (2): 234–243. JSTOR 4161203.
- Boreal Songbird Initiative : Blackpoll Warbler. Borealbirds.org. Retrieved on 2012-08-24.
- Hunt, P. D., and B. C. Eliason. 1999. Blackpoll Warbler (Dendroica striata). In The Birds of North America, No. 431 (A. Poole and F. Gill, eds.). The Academy of Natural Sciences, Philadelphia, and The American Ornithologists’ Union, Washington, D.C.
- Baird, p. 66
- Baird, p. 72
- Nisbet, Ian C. T.; McNair, Douglas B.; Post, William; Williams, Timothy C. (Autumn 1995). "Transoceanic Migration of the Blackpoll Warbler: Summary of Scientific Evidence and Response to Criticisms by Murray". Journal of Field Ornithology 66 (4): 612–622. Retrieved May 21, 2011.
- Murray BGJ (1989). "A Critical Review of the Transoceanic Migration of the Blackpoll Warbler". Auk 106 (1): 8–17. doi:10.2307/4087751.
- McNair, Douglas B.; Post, William (Autumn 1993). "Autumn Migration Route of Blackpoll Warblers: Evidence from Southeastern North America". Journal of Field Ornithology 64 (4): 417–425. JSTOR 4513849.
- New World Warblers by Curson, Quinn and Beadle, ISBN 0-7136-3932-6
- Blackpoll Warbler. The Cornell Lab of Ornithology: All About Birds. Access: May 20, 2011
- Baird, James (1999). Returning to the Tropics: The Epic Autumn Flight of the Blackpoll Warbler in Kenneth P. Able's Gathering of Angels. Ithaca, New York: Cornell University Press, pp. 63–78.
Names and Taxonomy
Comments: Phylogenetic analyses of sequences of mitochondrial and nuclear DNA (Lovette et al. 2010) indicate that all species formerly placed in Dendroica, one species formerly placed in Wilsonia (citrina), and two species formerly placed in Parula (americana and pitiayumi) form a clade with the single species traditionally placed in Setophaga (ruticilla). The generic name Setophaga has priority for this clade (AOU 2011).
Banks and Browning (1995) rejected the name Dendroica breviunguis for this species, but others have used it in the past (Hunt and Eliason 1999). Burleigh and Peters (1948) described morphological variation in eastern and western birds and proposed subspecies Dendroica striata lurida (western) and D. s. striata (eastern); Parkes (1954) subsequently refuted this distinction, and subsequently no subspecies were recognized by the American Ornithologists' Union (AOU 1957).