Birds of North Carolina
their Distribution and Abundance
Scientific Name:
Common Name:
 Family (Alpha):
PARULIDAE Members: Swainson's Warbler 473
General Comments
The Swainson's Warbler was once considered one of the rarest of warblers in the country. This perceived rarity was based as much on the extreme difficulty of actually seeing one without the use of a taped song as it is in terms of total numbers. It also has an unusual "bimodal" breeding range, nesting mostly in the Atlantic and Gulf Coastal Plains, but also to an extent in the southern Appalachians, with a hiatus in most of the Piedmont. In the Coastal Plain, it tends to require moderate to dense stands of cane beneath various canopy species, always in wetlands; these can be either riverine (swamps, bottomlands, and narrow streamside forested areas) or nonriverine (bay forests, taller pocosins, and even in some Loblolly Pine plantations). In the mountains and foothills, like the Worm-eating Warbler, it requires very dense and dark stands of Rosebay Rhododendron under various canopy species; Mountain Laurel or Carolina Rhododendron stands are occasionally used. These montane sites are usually near a stream, where the Swainson's loud song is often mistaken for the very similar song of the Louisiana Waterthrush. It is seldom detected in migration, as relatively few birds nest to the north of North Carolina, and as migrants are nearly silent. Despite some claims that the species is declining in overall numbers, such trends do not seem apparent in North Carolina; it seems as numerous now as it has ever been. In fact, singing males are appearing at more and more sites into the central Piedmont and across the mountains, where the presumed breeding range is expanding.
Breeding Status
Breeder
NC BRC List
Definitive
State Status
none
U.S. Status
Definitive
State Rank
S3S4B
Global Rank
G4
Coastal Plain
Summer resident. Breeds over essentially all of the region, as far west as Weldon (Halifax) and in the wider floodplains in the Sandhills (e.g., Drowning Creek in western Moore and northeastern Richmond). Formerly nested on the Outer Banks in Kitty Hawk Woods; however, it is apparently absent as a coastal breeder now. Generally uncommon but widespread throughout, probably nesting in all counties; fairly common in a few areas, such as near Green Swamp and Juniper Creek (Brunswick). Mainly mid-Apr to early or mid-Oct, but departure dates very poorly known, as the birds are silent in late summer and fall; best detected through mist-netting in fall. Peak counts: 15, along the Roanoke River (Halifax/Northampton), 26 May 2013; 13, Green Swamp (Brunswick), 28 Jun 1985; 13 at Howell Woods (Johnston), 30 Apr 2016.
Piedmont
Summer resident (sparingly), and scarce transient; however slowly increasing and spreading into the middle portions of the province, where formerly lacking. In summer, uncommon and somewhat local along the base of the Blue Ridge Escarpment (overlap with the Mountains), from Stone Mountain SP in the north southward to Rutherford (Chimney Rock SP) and Polk (Green River Gorge). More numerous in the southern portion (locally fairly common), north to McDowell, than in the northern portion. At the other end of the province, rare to uncommon in the extreme southeastern corner, in the Pee Dee River floodplain along the Richmond - Anson border, north at least to Pee Dee NWR. Formerly a few pairs nested along Morgan Creek (Orange - Durham), but birds have not been seen since about 1992. May have nested in Mecklenburg in 2006. Present in summer from 2021-23 at a site in Cabarrus, and thus perhaps nesting there. Presumed to have nested in southern Randolph in 2022, based on two adults and an attendant juvenile mist-netted at a single site in Jul. A singing male on territory along the Haw River (Alamance) from 29 Apr - 23 May 2023 was certainly on territory. In summer 2024, up to 4-5 were singing along the Cape Fear River in southeastern Chatham. Perhaps nests occasionally at South Mountains SP, Hanging Rock SP, and a few other foothills sites, but poorly known east of the Escarpment. Casual to very rare as a transient. Mainly mid-Apr to Oct, but departure dates very poorly known. Peak counts:
Mountain
Summer resident, increasing/spreading in range. Breeds most frequently along the Blue Ridge Escarpment (see Piedmont notes), mainly at the base, up to about 3,000 feet, but mostly below 2,500 feet. These sites are all on the Atlantic drainages. It also breeds along other Atlantic drainage streams in the Gorges area -- Toxaway, Horsepasture, Thompson, Whitewater, and Chattooga. Away from these slopes, it is generally rare to locally uncommon elsewhere. It is now (2025) found over many parts of Buncombe County in summer, for example. Can be fairly common in the Gorges area. Mainly mid- or late Apr to late Sep. Peak counts:
Finding Tips
Despite it not being common anywhere, you should be able to hear one to several in Alligator River NWR, Howell Woods Preserve (Johnston), and on back roads near Juniper Creek and Green Swamp. Chimney Rock SP and Gorges SP are also good, though the latter can be difficult to access. However, it is very difficult to spot a singing bird, as they seldom move during a bout of singing; you likely will need a tape recorder or smartphone. Be careful to avoid playing songs in restricted areas (various parks and preserves); such actions might be illegal.