Home, near and far.
Breeds across Canada, Alaska, and the northern and western United States. Winters from southern Mexico through Central America and as far south as Argentina and Bolivia.
Birds Heard
FIELD GUIDE
FIELD GUIDE
Thrushes and Allies
Swainson's Thrush
Catharus ustulatus
The Swainson's Thrush is a medium-sized songbird known for its ethereal, spiraling, flute-like song, often heard more than the bird is seen. This migratory species belongs to the thrush family and is well-camouflaged with subdued coloration. It is a common inhabitant of North American forests during the breeding season.
MigratoryMedium-sizedFlute-like songInsectivorous, Frugivorous
- Length
- 16-20 cm
- Wingspan
- 29-31 cm
- Weight
- 23-45 g
Typical adult measurements.
Individuals and populations vary.
01 / The telltale details
You’ll know it
when you see it.
Start with shape and behavior. Then look for the smaller details.
- 01
Eye-ring and Face
Features a prominent buffy eye-ring that extends to the lores, creating a 'spectacled' appearance, with buffy tones on the face.
- 02
Upperparts
The back is typically olive-brown, though western populations can be more russet-brown.
- 03
Underparts
Whitish underparts with distinct dark brown spots on the throat and upper breast.
- 04
Legs
Pink legs are characteristic.
02 / A place in the world
Where life
takes it.
Breeds in coniferous, mixed, and deciduous forests with dense undergrowth, often near water in riparian thickets. During migration, it can be found in various wooded areas, including parks and suburban yards.
Stay a while. Or follow the season.
A long-distance nocturnal migrant, the Swainson's Thrush travels between its North American breeding grounds and its wintering areas in Central and South America. Western populations migrate along the Pacific coast, while eastern populations take a more easterly route.
03 / Listen a little closer
A voice
of its own.
The song is a distinctive, ethereal, flute-like series of notes that spirals upward in pitch. Calls include a soft "whit" and a frog-like flight call heard during nocturnal migration.
04 / The life behind the feathers
A day in its world.
On the menu.
Primarily consumes insects and other arthropods during the breeding season. Its diet shifts to include a significant amount of berries and fruits, especially during fall migration and in its tropical wintering grounds.
Forages on the forest floor, gleaning insects from leaves and hopping to catch prey. It also hunts insects in the air, hovering and swooping like a flycatcher.
A place to begin.
The female builds a cup-shaped nest, typically 1-3 meters (3-10 feet) above the ground, on a horizontal branch in dense shrubs or conifer saplings. Nests are constructed from twigs, bark, moss, and leaves, often lined with finer materials.
The little routines.
Often shy and secretive, preferring to stay within dense thickets, making it more frequently heard than seen. Males defend territories by singing, sometimes engaging in singing duels.
One more reason to pay attention
A familiar face.
A few surprises.
The Swainson's Thrush was once known as the "mosquito thrush" due to its habit of catching flying insects.
Some western populations, known as "Russet-backed Thrushes," have warmer brown upperparts compared to the "Olive-backed Thrushes" found in the east.
Nests are sometimes lined with horsehair fungus, which may have antibiotic properties that deter pathogens.
05 / An eye for the difference
Could it be
someone else?
Veery
Catharus fuscescensThe Veery has less distinct breast spotting, a plainer face, and its song spirals downward in pitch.
Hermit Thrush
Catharus guttatusDistinguished by a reddish-brown tail that contrasts with its olive-brown back and a song that does not ascend or descend.
Grey-cheeked Thrush
Catharus minimusLacks the prominent buffy eye-ring and has a grayer face and neck.
Behind these field notesResearch & references · 12 sources
AI-assisted species research. Prepared September 2026. Details can vary across regions and populations.