Swainson's Thrushes are a common and beloved summer resident in Oregon, particularly west of the Cascade crest, known more for their ethereal, spiraling song than for flashy plumage. These birds are quite secretive and often heard more than seen, blending into the dense undergrowth of forests and woodlands.

A key point when describing male and female Swainson's Thrushes is that they exhibit minimal sexual dimorphism. This means that, for the casual observer in the field, it is extremely difficult to distinguish between males and females based solely on their appearance.

General Characteristics (Both Sexes):
Size and Shape: They are medium-sized thrushes, smaller than an American Robin but similar in general shape, with relatively long legs and a somewhat upright posture when perched.
Plumage:
Upperparts: Their backs, wings, and tails are a uniform olive-brown to russet-brown. The "Russet-backed Thrush" subspecies (*C. u. ustulatus*), found in western North America including Oregon, typically has a warmer, more reddish-brown tone to its upperparts compared to the "Olive-backed Thrush" subspecies found further east.
Underparts: They have pale, whitish underparts with a distinctive buffy wash on the breast and flanks, and dark spots on the throat and chest. These spots tend to be clear on the chest and become a bit smudgier lower down.
Eye-ring: A prominent and defining feature is their bold, buff-colored eye-ring, which extends slightly behind the eye, giving them a "spectacled" or "startled" look. This is a crucial ID mark to differentiate them from other similar thrushes like the Gray-cheeked Thrush (which lacks a prominent eye-ring) or the Hermit Thrush (which has a less distinct eye-ring and a reddish tail).
Bill: The bill is relatively short, straight, and dark, sometimes with a paler base.
Legs: Their legs are dull pinkish or brownish-pink.
Behavior: Swainson's Thrushes often forage on the ground, gleaning insects from leaf litter, but will also take berries and fruits, especially later in the season. They are generally shy and remain hidden in dense vegetation.
Vocalization: This is perhaps their most recognizable trait. Their song is a beautiful, fluting, spiraling series of notes that ascend in pitch, often described as "oh, holy, holy, holy, oh, slow, slow, slow, oh, sweet, sweet, sweet." They also have a distinctive "whit" or "whit-burr" call note, often heard during migration, particularly at night.

Distinguishing Male and Female Swainson's Thrushes in Oregon:
As mentioned, there are no obvious visual differences in plumage between male and female Swainson's Thrushes.

Appearance: Both sexes share the same olive-brown upperparts, buffy eye-ring, and spotted breast. Any slight differences in size (males may be marginally larger on average) are not discernible in the field.
Behavioral Cues (most reliable):
Singing: The male is the primary singer, especially during the breeding season (late spring and summer) to establish and defend territory and attract a mate. If you hear the distinctive spiraling song, it's almost certainly a male.
Territory Establishment: Males typically arrive at breeding grounds a few days earlier than females and will establish and defend their territories through song.
Nest Building: The female alone constructs the cup-shaped nest, typically in a small tree or shrub, often concealed in dense foliage.
Incubation: Only the female incubates the eggs.
Parental Care: Both parents participate in feeding the young after hatching.