Swainson's Warbler
Limnothlypis swainsonii
Shy and difficult to see in deciduous forest with dense understory, often near water. Plain buffy-brown coloration with rufous crown and dark eyeline. Also note disproportionately large, sharp, pinkish bill and pink legs. Shimmies tail side-to-side as it slowly forages on the forest floor, investigating fallen leaf litter for insects. Fairly restricted breeding range in the southeastern U.S.; winters primarily on the Yucatan peninsula and in the Caribbean. Listen for loud, sweet song, similar to Louisiana Waterthrush but without the complex ending.
Identification
Swainson's warblers are a small and rather nondescript songbird, though are fairly large for a New World warbler. Adults grow to 12.5–16 cm (4.9–6.3 in) in length and 11–20.5 g (0.39–0.72 oz) in weight. The wingspan averages 23 cm (9.1 in). They are a plain olive-brown above and pale yellow-white below. They have a whitish eyebrow stripe that runs above their eye, and the top of their head is a rusty brown. Unlike most other New World warblers that are mostly dimorphic, there is no difference in appearance between a male or female Swainson's warbler.
Taxonomy
No subspecies are recognized. There appears to be some divergence between populations from Arkansas and others of the coastal plains. This does fit a pattern one would expect from genetic drift, but there seem to be no geographical or ecological barriers restricting gene flow. Even during the last ice age, when average temperatures, precipitation and sea levels were lower, there seems to have been ample contiguous habitat. Clearly, some factor restricting gene flow is at work, but it is not presently known what it is. It is possible that the subpopulations conform to the different wintering areas.<p>In some migrant birds it is known that the initial direction of the migration is set by fairly simple hereditary mechanisms. Offspring of pairs comprising birds of different subpopulations will, in such species, attempt to migrate into an intermediate direction. Such a course would lead a Swainson's warbler deep into the Caribbean where there are no wintering or even stopover points, and the bird would almost certainly perish. More research such as analyzing bird banding data is needed to determine whether this mechanism applies in Swainson's warbler.
- Scientific name
- Limnothlypis swainsonii
- Authority
- (Audubon, 1834)
- Order
- Passeriformes
- Family
- Parulidae
- Genus
- Limnothlypis
Range and habitat
Swainson's warblers are uncommon, mostly found in flooded swamplands and canebrakes of the south-eastern United States. More rarely, they will also occur in rhododendron thickets in the southern Appalachian Mountains. They are a migratory species, with part of the population migrating southeastwards to the Greater Antilles (where it overwinters in the Blue Mountains of Jamaica for example) and the other southwestwards to the Yucatán Peninsula region in winter.
- Breeding range
- NA : se USA
- Non-breeding range
- MA and West Indies
- Migration
- Complete migrants
Behavior
Migration pattern: Complete migrants.
Conservation
Population trend: rising.
- Population trend
- rising
Photos
Distribution
Bird Calls
Other Birds
Southern Tropical Pewee
Contopus cinereus
Small, gray flycatcher lacking strong markings. Note its peaked crown and yellow lower half off bill. Some birds may show faint wingbars and a slight yellowish cast to the belly. Little overlap with other pewees; in the Andes it might be found together with Eastern Wood-Pewee or Western Wood-Pewee during the northern winter. Southern Tropical Pewee has shorter wings, a longer tail, and may show a faint spot between the bill and eye. Voice is the most reliable way to separate them. Listen for an explosive “CHIpeer” as well as a series of sharp chip notes. Typically encountered at forest edge or in clearings. Often perches on an exposed branch, from which it flies out to chase insects in looping, acrobatic sallies.
Plumbeous-crowned Tyrannulet
Phyllomyias plumbeiceps
Small uncommon flycatcher in the subtropical zone of the Andes from Colombia to Peru. It has a pale yellow belly, gray crown, dark ear patch, and yellow edges on the wing feathers. Very similar to many other small flycatchers like Ashy-headed and Ecuadorian Tyrannulets or bristle-tyrants; probably best identified by voice. Listen for loud “pip!” calls, often followed by a sputter. Occurs in the middle to upper levels of humid cloud forest from around 1,300–2,200 m. Singles or pairs often follow mixed-species flocks.
Dja River Swamp Warbler
Bradypterus grandis
A large gray-brown warbler with a long and graduated tail, a white throat, and a heavily streaked upper breast. A highly localized resident in wetlands and swamps with tall sedge, typically within the forest zone; also occurs in adjacent tall grass and forest edge. Secretive and furtive, often creeping around close to the ground within its preferred habitat, but it will also sit up to defend its territory. Sings a strident and distinctive song with 3–4 downslurred “seet” introductory notes that accelerate into a throaty trill. Little Rush Warbler is smaller than Dja River Swamp Warbler and has a different song.
Start Your Bird Watching Journey
Identify a bird outdoors and keep the field guide close for your next observation.