Black-throated Blue Warbler

Setophaga caerulescens


Distribution, Migration, and Habitat

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Figure 1. Breeding and wintering ranges of the Black-throated Blue Warbler.

See text for details.

eBird range map for Black-throated Blue Warbler

Generated from eBird observations (Year-Round, 1900-present)

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Use our distribution analysis tool to view predicted relative abundance in specific areas of the Black-throated Blue Warbler range.

Figure 5. Relative abundance of Black-throated Blue Warbler during the breeding season.

Based on data from the North American Breeding Bird Survey, 2011–2015. See Sauer et al. (2017) for details.

Figure 2. Annual cycle of breeding, molt, and migration of the Black-throated Blue Warbler.

Figure depicts phenology for the northeastern United States. Thick lines show peak activity, thin lines off-peak activity.

Black-throated Blue Warbler breeding habitat, New Hampshire.

High elevation at Hubbard Brook Experimental Forest. Nests are often placed low in the hobblebush (Viburnum lantanoides) (foreground).

© Sara Kaiser, New Hampshire, United States, 20 June 2011
Black-throated Blue Warbler breeding habitat, New Hampshire.

A northern hardwood forest at Hubbard Brook, showing the dense heterogeneous shrub layer of sugar maple, beech, and hobblebush.

© Sara Kaiser, New Hampshire, United States, 20 June 2011
Black-throated Blue Warbler breeding habitat, North Carolina.

Nests are often placed in Rhododendron thickets.

© Mason Cline, North Carolina, United States, 1 May 2012
Black-throated Blue Warbler breeding habitat, North Carolina.
© Mason Cline, North Carolina, United States, 1 May 2012
Typical Black-throated Blue Warbler overwintering habitat: a wet limestone forest in Jamaica.

Photo: Alexander Sliwa, near Windsor, Trelawny Parish, Jamaica, 1988.

Black-throated Blue Warbler overwintering habitat: a shade-coffee plantation in Jamaica.
© Wendy Willis, Saint Thomas, Jamaica, 30 January 2017

Distribution in the Americas

Breeding Range

Figure 1. Breeds at higher elevations in the southern Appalachians from northern Georgia, western portions of South Carolina and North Carolina, eastern Tennessee and Kentucky, north to western West Virginia and Pennsylvania to the Adirondacks of New York, in western Massachusetts, Vermont, New Hampshire, Maine, New Brunswick, Nova Scotia, west to Quebec, southern Ontario, eastern Saskatchewan, and northern Michigan. Also occurs in northern Wisconsin, northeastern Minnesota, Prince Edward Island, and Nova Scotia, although irregularly and at low densities (American Ornithologists' Union 1983).

Northern limit. In Quebec (Darveau 1996a), widespread in southern third of province, from ca. 49° N to the U.S. border. Highest concentrations in St. Lawrence valley and environs. In Ontario (Fraser 1987a), widely distributed within zone extending from southern edge of Canadian Shield (ca. 49°N) to Kapuskasing (ca. 44°N), with concentrations north and east of Georgian Bay to Ottawa River. Absent from regions immediately north of Lake Erie and Lake Ontario. In the Maritime Provinces (Erskine 1992a), widespread but sparse in New Brunswick and the southern half of Nova Scotia; much rarer and more widespread in eastern and northern Nova Scotia, and on Prince Edward Island. In New York, breeds in areas mainly above 305 m elevation, with centers of abundance in the Adirondacks, Catskills, and eastern Appalachian Plateau (McGowan and Corwin 2008).

Southern limit. In Kentucky (Palmer-Ball 1996), confined to mountains of extreme southeast (Black Mountain), although fairly common in this region. In Tennessee (Nicholson 1997b), restricted to far eastern reaches (higher elevations of Appalachian Mountains), with a small isolated population in the Cumberland Mountains (east-central portion of the state). Common breeder in mountains of western North Carolina; breeds sparsely at mid elevations of the Piedmont (Potter et al. 1980). In westernmost South Carolina (Pitts 1993) and northern Georgia (Georgia Ornithological Society 2003), fairly common breeder in mountains (generally above 800 m). Not known to breed at lower elevations at the southern end of the breeding range.

Western limit. In West Virginia (Bucklew and Hall 1994), confined mainly to eastern mountain regions (Alleghenies at > 600 m; and higher regions of southern Western Hills). Very rare breeder in northeastern Ohio (Rodewald et al. 2016). In Michigan (​), fairly common summer resident throughout the Upper Peninsula and on Isle Royale; south less commonly along Lake Michigan as far as Muskegon. Nesting recorded south to Muskegon, Ottawa, and Kalamazoo counties; not regularly found in summer anywhere in Lower Peninsula except in northernmost tip. In Wisconsin, breeds sparingly in northern counties (Robbins 1991); rare in western Wisconsin (e.g., only 28 specimens among the over 40,000 warblers killed during fall nocturnal migration at the Eau Claire TV tower during the 1980s). In Minnesota, scattered breeding northeast and north-central, scarce except in Cook County (Janssen 1987).

Overwintering Range

Figure 1. During the overwintering period, most occur in the Greater Antilles, from Puerto Rico, Hispaniola, Cuba to Jamaica; also in the Bahamas. Occasional in the Lesser Antilles, as far south as Trinidad (ffrench 1991a) and along the Caribbean coast of the Yucatan, Belize, Honduras. Recorded as rare or casual visitor along the Caribbean coasts of Costa Rica, Panama, Colombia, and Venezuela (Ridgely and Gwynne 1989). One record from Ecuador of a male present from February through early June along east slope of Andes near Cosanga, Napo Province (Martin et al. 2004d). Recorded occasionally in Tabasco, Mexico City and other non-Caribbean coastal localities in Mexico (Calderon-Parra and Ortega-Alvarez 2014, Heredia et al. 2015). Small numbers overwinter in southern Florida and a few occasionally farther north (Root 1988b, American Ornithologists' Union 1998a).

Breeding areas of overwintering birds are largely unknown, as recoveries in overwintering range of birds banded in the temperate zone (and vice versa) are scarce. As of February 2017, there were 10 such recoveries in the U.S. Fish and Wildlife Service records, 6 from Cuba, 2 from Hispaniola, and 1 each from Guatemala and Panama (U.S. Geological Survey Bird Banding Lab data; see also Holmes et al. 1992). All 10 of these individuals had been banded on migration (spring or fall) in eastern North America, thus providing no information linking breeding and wintering distributions for specific individuals or populations. Studies using stable isotopes in feathers as markers of geographic origins indicate that individuals from the northern part of the breeding range winter mostly in Cuba and Jamaica, while those that breed south along the Appalachians winter mostly in Hispaniola and Puerto Rico (Rubenstein et al. 2002). Preliminary data with geolocators confirm this pattern: of 4 geolocator recoveries thus far (2016), 2 birds overwintered in Jamaica, 1 in Cuba and 1 in the Dominican Republic (M. T. Hallworth, unpublished data).

Distribution Outside the Americas

One record of an adult male from Iceland in September 1988 (Alström and Colston 1991).

Nature of Migration

Known from seasonal changes in regional occurrence and from a few recoveries of banded birds. In general, birds leave breeding grounds late August to mid-September, with a few individuals still present in late September-mid October (RTH). Four observational records in New Hampshire in winter (December, January) (Keith and Fox 2013). Arrival in winter quarters in Jamaica in early to mid October (RTH). Depart winter sites in late March to April, arrive in breeding areas late April through mid to late May. Remain mostly in shrubby or forested habitats during migration stopovers.

Timing and Routes of Migration

Departs breeding grounds from mid to late August through early October (Hubbard 1965b, RTH; see Figure 2). Peak southward movement through New Hampshire occurs from last week of August through first 2 weeks of September (Keith and Fox 2013). Based on a color-banded population at Hubbard Brook Experimental Forest in New Hampshire, some adults remain on or near breeding territories through late September and even into early October (RTH). In the Green Mountains of Vermont, some, mostly hatch-year individuals, move upslope to high-elevation forests in August and September before migrating south (Rimmer and McFarland 2000). Appear to migrate southward on a wide front along the eastern seaboard from the Appalachians to the Atlantic coast. Those near the coast are mostly young of the year (hatch-year) individuals (Ralph 1981, Stewart 1986); in inland areas, adults are more frequent than young (Hall 1981). First appear along the Allegheny Front in western West Virginia in early to mid August, with peak numbers of hatch-year birds in mid September and adult (after-hatch-year) birds in late September through the first week of October (Hall 1981, Rimmer and McFarland 2000). In this region, there is no differential passage of males and females (G. Hall, personal communication). First appear in coastal Virginia by late August, but main passage there is from late September through mid October (Stewart 1986), and in Florida between late September through about mid October (Taylor 1973c). Extreme dates in central Florida range from 10 September to 19 November (Taylor 1973c) and in southern Florida from 22 September to 5 November (Fisk 1979). Tower-kill samples in Florida indicated that both ages and sexes migrate together, hatching-year birds tending to pass through earlier than adults (Taylor 1973c). An abundant passage migrant in autumn on the Dry Tortugas (Griscom and Sprunt 1957).

In some years, a few individuals arrive in Jamaican overwintering areas as early as mid to late August (R. and A. Sutton, personal communication), but the main influx occurs from late September to mid October (RTH). Overwintering populations appear to be stabilized by late October to early November in Jamaica (Holmes et al. 1989, RTH) and Puerto Rico (Wunderle 1995). At high-elevation sites in Puerto Rico, young (hatch-year) birds often arrive before adult (after-hatch-year) birds, but there are no significant differences between arrival dates of males and females (Wunderle 1995).

Generally rare anywhere west of the Mississippi River, but has occurred in most states west to the Pacific coast (American Ornithologists' Union 1983). West of the Great Plains, regular in autumn in California (24 September–8 November; Roberson 1980), with a concentration of records in October. Recorded primarily along the coastline in northern California, but occurs inland more frequently in southern California. Also recorded in Oregon primarily during the fall (Roberson 1980).

Departure from overwintering grounds in the Caribbean occurs from late March to mid April (RTH). One extralimital record in Ecuador of a male present through early June (Martin et al. 2004d). Earliest spring arrival in Florida is late March (Cooke 1904), with main passage mid to late April. Northward migration appears to be inverse of that in fall, with individuals moving northward mainly through Florida, spreading out along the Atlantic seaboard, most birds staying east of the Appalachians. Relatively few are recorded in midwestern U.S. south of Indiana, which suggests that those seen migrating through the upper Midwest must have crossed the Appalachians and then fanned northwestward (Cooke 1904, Bent 1953b). Cairns (in Bent 1953b) stated that local breeders arrive in western North Carolina 10 d before those that pass northward, and might already be building nests when migrants are still passing through.

Spring passage through Michigan ranges from late April through May, with adult (after-second-year) males arriving before first-year males and females (Hubbard 1965b). In southern Ontario, males arrived on passage an average of 5.7 d before females (Francis and Cooke 1986). At Hubbard Brook in New Hampshire (1986–2010), arrival of males on breeding territories occurs during the first half of May (median arrival date 10 May; Lany et al. 2016), with arrival of most individuals completed by 15–20 May in most years (RTH). Returning adult males arrive first, followed a few days later by females and young males. Very rarely recorded in spring in California and other western states (Roberson 1980).

Migratory Behavior

Little specific information for this species. However, in a modeling study (Reilly and Reilly 2009), data from this species were used to examine fitness consequences of orientation routes taken by juveniles in their first southward (autumn) migration. Assuming that juveniles tend to orient on a predetermined vector and make little or no adjustment for wind displacement, their simulations showed that a bet-hedging strategy in the form of within-clutch variation of migratory orientation patterns would maximize geometric mean fitness of the adults. The modeling results were consistent with the observed wide variation in the migratory tracks of juvenile passerines and with the fact that many juvenile songbirds, including those of this species, concentrate along the Atlantic coast of the U.S. as they move southward (Ralph 1981, Stewart 1986; see above).

Control and Physiology of Migration

During migration, stops to forage in appropriate habitat and increases in mass (Morris et al. 1996, Bonter et al. 2007, Seewagen and Slayton 2008). At a stopover site on the southern shore of Lake Ontario in New York, energetic condition (size-corrected body mass) was greater in spring than in autumn, and greater in females compared to males during both migratory seasons (Holzschuh and Deutschlander 2016). In this same study, body condition increased with arrival date in spring, supporting the ‘breeding performance’ hypothesis, that birds may carry excess energy reserves in spring, which can be used for subsequent reproductive efforts.

Habitat in Breeding Range

Breeds mainly in large, more or less continuous tracts of relatively undisturbed deciduous or mixed deciduous/coniferous forests containing dense shrub layers. In the Appalachians, this species occurs mostly at higher elevations (800–1600 m; Burleigh 1958, Simpson 1992, Lichstein et al. 2002, Graves and Romanek 2009), while farther north it may be found at lower elevations but mostly in hilly or mountainous landscapes. In New York, occurs mainly above 300 m, absent at lower elevations, including the major river valleys and coastal lowlands (Anderle and Carroll 1988). In New Hampshire, most abundant at in northern hardwood forests dominated by maples (Acer), birches (Betula) and beech (Fagus) at elevations of 400–700 m, with few if any in the boreal zone above about 900 m (Foss 1994a, DeLuca and King 2017, RTH); widely distributed but at low density at lower elevations except in the southeastern coastal region (Foss 1994a, RTH). Upper elevational boundary of distribution in the White Mountains may be shifting upslope due to recent climate warming (DeLuca and King 2017; see Conservation and Management). Widespread in Vermont but mostly at mid and higher elevations (Laughlin and Kibbe 1985, Renfrew 2013b). In northern Michigan, this species occupies similar forest types (mostly maple-dominated northern hardwoods), although in Michigan, it can also be found, especially during the post-fledgling period, in dense patches of regenerating aspen (Populus), spruce, or in red pine plantations (Pinus resinosa) with a dense, deciduous sapling understory (K. R. Hall, personal communication). Prefers deciduous or mixed conifer-deciduous forests in Quebec (Girard et al. 2004).

Forests most suitable as breeding habitat contain a relatively thick undergrowth of dense, usually deciduous or broad-leaved evergreen shrubs. The plant species comprising this shrub layer vary geographically; in the mountains of New Hampshire and Vermont, mostly hobblebush (Viburnum lantanoides), along with small saplings of sugar maple (Acer saccharum), American beech (Fagus grandifolia), striped maple (Acer pensylvanicum), and conifers such as red spruce (Picea rubens) and balsam fir (Abies balsamea; Laughlin and Kibbe 1985, Steele 1992, Steele 1993, RTH). In more southerly areas, the species occurs ... “where there is more or less thick undergrowth of mountain laurel, rhododendron, creeping yew, deciduous bushes, small saplings, or tiny conifers” (Bent 1953b; see also Graves and Romanek 2009, Stodola et al. 2009). In northern Michigan, where shade-tolerant understory shrub species are typically rare, or have been removed by white-tailed deer (Odocoileus virginianus), this species tends to respond positively to low-intensity harvest (e.g., selection cutting) of closed-canopy forest, which opens the forest canopy and promotes dense patches of seedlings and saplings (Hall 2008), especially of balsam fir (Kearns et al. 2006). However, habitat occupancy models reported by Smith et al (Smith et al. 2008) indicated that shrub density in Vermont was less important than shrub species composition (warbler abundance negatively related to % conifers in understory).

Found on steep slopes among tangled vines and moss-covered logs in North Carolina (Cairns, in Bent 1953b), in heavily wooded ravines along streams, seepages and river forests in South Carolina (Pitts 1993), and in northern hardwoods and mixed deciduous-boreal forests including heath balds in the Blue Ridge Mountains (Simpson 1992). Selection of habitats with a dense shrub layer seems most closely related to nesting requirements and not to foraging needs or other factors (Holway 1991, Steele 1993).

Densities vary with forest type, shrub density, and land-use history and practices. In Quebec (in Darveau 1996a), lowest breeding densities found in coniferous stands: 1.7 pairs/10 ha in hemlock, 1.6/10 ha in red spruce, and 2.2/10 ha pairs in balsam fir; by contrast, 6.4 pairs/10 ha in a white birch stand and 10.8 pairs/10 ha in sugar maple–yellow birch. Greatest variations in density were seen in heterogeneous deciduous stands (Table 2). In New Brunswick, abundance increased following selection harvesting, which resulted in thicker shrub layer (Hache et al. 2013). Abundance in southern Appalachians associated with the amount of older and more structurally diverse forest (Lichstein et al. 2002, Lichstein et al. 2002). In Vermont, abundance increased with increasing shrub density, but this was more pronounced in fragmented landscapes than in contiguously forested tracts (Cornell and Donovan 2010a, Cornell and Donovan 2010b). Avoids recent clearcuts (3–5 years postcut) despite shrubby nature of vegetation there (King and DeGraaf 2000), but may be found in areas clear-cut after 15 years or more of regrowth (DeGraaf and Yamasaki 2001). In White Mountains, New Hampshire, territories found to occur more often in forest adjacent to clearcuts than in forest interior (King et al. 1997).

Demographic studies in the unfragmented forest at Hubbard Brook, Grafton County, New Hampshire show that older individuals occupied smaller territories and had higher reproductive success in areas with high shrub densities (Holmes et al. 1995, Doran and Holmes 2005; see Demography). Similar positive relationships between abundance, shrub density, and fecundity were reported from studies in western Maine (Harris and Reed 2002b) and in both fragmented and continuous forests in Vermont (Cornell and Donovan 2010a).

Mechanisms of habitat selection by this species have been examined in several studies. Using dynamic site-occupancy models, individual males moved up a habitat-quality gradient when possible, i.e., from sites with low to high shrub densities (Betts et al. 2008a, Rodenhouse et al. 2003). In a companion study, individual males were experimentally enticed to settle and establish territories in areas of poor quality habitat by using song playbacks, suggesting that social cues are important in site selection (Betts et al. 2008b) . Their experiment involved broadcasting song during the latter part of the breeding period (18–31 July) in areas of low shrub density that had previously been unoccupied (= poor quality habitat), and finding that these sites were 4 times more likely to be settled in the following spring than control sites. Colonizers included both first time breeders (first-year or SY birds) and older adults. Heterospecific interactions in habitat settlement were also examined in these experiments (Betts et al. 2010). These researchers propose that both natal and breeding dispersers used social information gathered in late summer (“prospecting”) to determine where to settle in the subsequent spring. This explanation assumes that post-breeding song is highly correlated with good reproductive success, and thus serves as a reliable cue for site quality. Subsequently, in fragmented forests in Vermont, vegetation structure (shrub density) was a more reliable signal of reproductive performance than social cues (Cornell and Donovan 2010b). They latter authors also proposed that habitat selection might be a two-step process, with birds first being attracted by song (or perhaps just the physical presence of conspecifics) and then second, by responding to local characteristics of the vegetation (i.e., denseness of the shrub layer).

In a modeling study, macroclimate variables found to be important in determining breeding distribution in Ontario, although underlying mechanisms unclear (Venier et al. 1999). Marked constrictions of habitat into northern New England and along higher elevations of Appalachian Mountains predicted from habitat models of current distribution and four scenarios of climate change (Matthews et al. 2011; see maps at

Recent methodological advances in remote sensing have allowed for detection and quantification of habitat characteristics important to this and other species. Using Light Detecting and Ranging (LIDAR), Goetz et al. 2010 quantified habitat heterogeneity (e.g., vertical distribution of foliage, canopy height) at Hubbard Brook in New Hampshire, and were able to predict the distribution of this species across the forested landscape. Follow-up studies (Swatantran et al. 2012) compared LIDAR, radar, and multispectral remote-sensing methods for predicting the prevalence (abundance) of 8 forest songbird species at Hubbard Brook, including the Black-throated Blue Warbler.

Following breeding, individuals often move to early successional habitats, as evidenced by significantly higher abundance during the post-breeding period in clear-cuts than in either undisturbed forest or wildlife openings (Chandler et al. 2012).

Habitat in Migration

Information incomplete and not available from systematic observations in all possible habitats. Recorded along forest edges, riparian woodlands, and other well-vegetated habitats, including parks and gardens (Bent 1953b). In spring, often found in well-developed upland or riparian forests, feeding at intermediate (5–10 m) heights (Parnell 1969). In Pennsylvania, most abundant during migration in mature forest interior (Keller et al. 2009) and/or along forest/agricultural edges (Rodewald and Brittingham 2007). Additional studies quantifying habitat use at stopover sites are needed.

Habitat in the Overwintering Range

Generally dense tropical forests and woodlands, ranging from near sea level to high elevations (Holmes et al. 1989, Sliwa 1991, Wunderle 1992, Wunderle and Wade 1993). Occurs in second-growth habitats as long as they contain woody trees and usually dense understories (Lack and Lack 1972, RTH). In Jamaica, most common at mid- and higher elevations in well-developed wet limestone forest, along fence rows, in agricultural lands (especially coffee and citrus plantations), and in shrubs and trees around gardens and houses (Lack and Lack 1972, Sliwa 1991, Murphy et al. 2001a, Jirinec et al. 2011, Campos 2012, RTH). In both Jamaica and Puerto Rico, males more common in closed-canopy forest at lower to mid-elevations, while females dominate at higher elevations, often in shrubbier vegetation (Sliwa 1991, Wunderle 1992, Wunderle 1995), showing sexual habitat segregation in winter for this species. Sex ratios in shade coffee plantations in the Dominican Republic are male-biased (Wunderle and Latta 2000), whereas those in more open sun-coffee plantations are female-biased (Wunderle and Latta 1996). Distribution with shade-coffee farms in Jamaica associated with high overstory canopy and dense understory coffee bushes within intermediate distances to non-cultivated habitat (Campos 2012). In the latter situation, individuals found to feed among coffee bushes during the day and roost, sometimes communally, in overstory shade trees or in adjacent forests (Jirinec et al. 2011).

Based on stable isotope analyses, individuals wintering in more mesic habitats found to be in better body condition during northward migration than those from drier sites (Bearhop et al. 2004). Whether this effect carries over to influence breeding season activities or survival as reported for American Redstarts (Setophaga ruticilla) (Marra et al. 1998, Reudink et al. 2009a), however, is unknown. The possibility of such carry-over effects between seasons for this species is in need of study (see Demography: Range).

Historical Changes to the Distribution

Little known. Prior to European colonization, this species presumably had a wide distribution in the then extensive deciduous and mixed deciduous/coniferous forests of northeastern U.S. and eastern Canada. As these forests were cleared or logged in the 17th and 18th centuries (Irland 1982, Whitney 1994), suitable breeding habitat for this warbler probably shrank considerably, tracking the westward human migration (Keith and Fox 2013). With the subsequent abandonment of farmland in New England and other parts of the Northeast starting in the early to mid-19th century and continuing until forested habitat increased again in the late 19th and 20th centuries (Litvitas 1993, Foster and Aber 2004). Thus, breeding habitat for this species is probably more extensive now in the early 21st century than it was 100–150 yr ago.

Fossil History

Not known.

Recommended Citation

Holmes, R. T., S. A. Kaiser, N. L. Rodenhouse, T. S. Sillett, M. S. Webster, P. Pyle, and M. A. Patten (2017). Black-throated Blue Warbler (Setophaga caerulescens), version 3.0. In The Birds of North America (P. G. Rodewald, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA.