SPECIES

Blackpoll Warbler Setophaga striata Scientific name definitions

William DeLuca, Rebecca Holberton, Pamela D. Hunt, and Bonita C. Eliason
Version: 1.0 — Published March 4, 2020
Text last updated June 4, 2013

Habitat

Habitat in Breeding Range

Across n. Canada, found primarily in boreal black spruce (Picea mariana) and tamarack (Larix sp.) forest (Bent 1953b, Errington 1933, Jehl 2004). In western part of range also occurs regularly, if not primarily, in spruce-alder (Alnus spp.)-willow (Salix spp.) thickets in riparian areas or the transition zone between taiga and tundra (Gabrielson and Lincoln 1959; Theberge 1976; Kessel 1998). Populations in the ne. U.S. and se. Canada occupy coastal or subalpine forests of white spruce (P. glauca), red spruce (P. rubens), and balsam fir (Abies balsamea; Morse 1979a, Sabo 1980). In the subalpine zone, also found in mixed forests of conifers and birch (Betula spp.), mountain ash (Sorbus americana), pin cherry (Prunus pensylvanica) or aspen (Populus spp.), including second growth, down to 500 m (Morse 1979a, Andrle and Carroll 1998).

Isolated breeding records south of main breeding range have occurred in spruce bogs or conifer swamps at relatively high elevations (≥700 m; Walley 1989a, Gross 1994, 2010). Habitat stands occupied on Mt. Moosilauke, NH, had mean canopy height of 6.4 m, 57% canopy cover, 69% of foliage volume in conifers, and mean tree diameter at breast height (dbh) of 9 cm (Sabo 1980). Sixty to 97% of trees on census plots above 950 m on Mt. Osceola, NH, were balsam fir (Morse 1979a).

In the ne. US occupies subalpine forests in early successional stages after wind falls or regenerating fir waves as well as intermediate stages of succession and mature forest (WVD). At a regenerating 10-yr-old clearcut at 700 m in central New Hampshire, dominant trees included paper birch (Betula papyrifera), pin cherry, red and mountain maple (Acer rubrum and A. spicatum) and balsam fir; most trees <7 cm dbh and <4 m tall. Densities of stems ≥3 cm dbh = 5.8/10 m2, stems <3 cm dbh = 23.6/10 m2 (PDH).

On Kent I., NB, tree species composition on Blackpoll Warbler territories was 8.8% white spruce, 28.3% red spruce, and 62.9% balsam fir. Blackpolls occur in 2 distinct habitat types based on large tree density (trees > 2 m tall and 8 cm dbh): areas dominated by white spruce with modal densities of 11–20 large trees/100 m2, and areas dominated by balsam fir and red spruce with modal densities of 51–60 large trees/100 m2 (Eliason 1986b).

Transitions to primarily deciduous shrub habitats (Salix alaxensis and Alnus incana) in Alaska, where riparian or other moist habitats are preferred. Also occupies ecotone between treeline tiaga and alpine tundra (Kessel 1998). Average shrub height of occupied plots was 2.6 m, with 69% of occurrences in habitats with heights of 1.3–2.8 m (Kessel 1998).

No detailed data on tree species composition and densities for most of breeding range. See also Food habits: feeding, and Breeding: nest site, below.

Habitat in Nonbreeding Range

Habitat in Migration

Wide variety of habitats, although often partial to spruces, even when they are only a small component of the habitat. During fall passage period at Churchill, forages primarily in spruce and tamarack. While moving through n. NY and New England, montane forest habitats appear to be preferentially selected (Rimmer and McFarland 2000). Farther south in New England, commonly occurs in mature and secondary growth of mixed deciduous trees and shrubs. In N. Carolina, most common in oak-hickory forest and wet thickets in spring (Parnell 1969). More common in alpine habitats than in nearby valleys during fall in n. New Hampshire (T. Williams pers. comm.). Found in virtually any vegetated habitat during stopover in the Caribbean, including residential areas, mesquite savannah, mangrove forest, and dry forest (M. Baltz pers. comm., PDH). In South America, ranges up to 2,500 m during migration (Ridgely and Tudor 1989).

Habitat in Overwintering Range

Recorded from most wooded habitats in South America, including deciduous, rain, cloud, mangrove, and gallery forests (De Schauensee and Phelps 1978), as well as forest edges and second growth (Paynter 1995) and coffee plantations (J. Jones pers. comm.). Generally found below 1,600 m in Venezuela (Paynter 1995) and 2,600 m in Colombia (Hilty and Brown 1986). Abundance may be highest in second growth habitats on islands in major rivers (Pashley 2010).

Blackpoll Warbler Figure 2. Proposed migration routes of the Blackpoll Warbler.
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Figure 2. Proposed migration routes of the Blackpoll Warbler.

Fall route largely based on Nisbet 1970 and Nisbet et al. 1995. Spring route based on examination of local distributional works. Map does not include areas where the species is rare in migration or occurrences along the Pacific coast. See text for details.

Blackpoll Warbler Blackpoll Warbler with fat reserves, Powdermill, PA, 11 October.
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Blackpoll Warbler with fat reserves, Powdermill, PA, 11 October.

Blackpoll Warblers migrate from the northeastern North America mostly over the open Atlantic Ocean to reach wintering areas in South America. This journey requires that they pack on fat reserves. In the photo on top, the visible subcutaneous (i.e., beneath the skin) fat is extensive along the sides, appearing as an orangish mass below the skin. At just 17.1g, however, this Blackpoll was far from Powdermill's record heavy weight for this species of 23.2g (imagine all traces of the breast musculature rendered invisible by fat!)

Blackpoll Warbler Basic plumage Blackpoll Warbler, off the Maine coast, 5 October.
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Basic plumage Blackpoll Warbler, off the Maine coast, 5 October.

It is difficult to age and sex Blackpoll Warblers with certainty in fall in the field. Fall adult males generally show more streaking below and a dark lateral throat stripe. This bird is aged as an adult based on its broad truncate primary coverts, and is thus likely an adult female. This bird landed on a ship off the coast of Maine during migration. The following is a link to this photographer's website: http://www.flickr.com/photos/bonxie88/.

Blackpoll Warbler Blackpoll Warbler breeding habitat, Terra Nove NP, NL, 1 June.
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Blackpoll Warbler breeding habitat, Terra Nove NP, NL, 1 June.

Blackpoll Warbler breeds across an extensive range from Newfoundland to western Alaska. The following is a link to this photographer's website: http://www.flickr.com/photos/oceanites/.

Recommended Citation

DeLuca, W., R. Holberton, P. D. Hunt, and B. C. Eliason (2020). Blackpoll Warbler (Setophaga striata), version 1.0. In Birds of the World (A. F. Poole, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.bkpwar.01