The bill measures 1.5–1.9 cm (0.59–0.75 in) in length and the tarsus is 2.5 to 3.1 cm (0.98 to 1.22 in) long. They forage on the forest floor, also in trees. This species is 16–20 cm (6.3–7.9 in) in length. Olive-brown above with a distinct buffy eyering. Adults are brown on the upperparts. This species may be displaced by the hermit thrush where their ranges overlap. The genetic differences between the subspecies, and the circuitous migratory route of the continental birds, strongly suggest that these species underwent a rapid range expansion following the end of the last ice age, with populations originally summering in the south-east of North America expanding their ranges northwards and westwards as the ice retreated. Catharus ustulatus. Despite being closer to the Pacific Coast than the Gulf of Mexico, inland breeders in BC cross the Northern Rockies and the central US in order to cross the Gulf of Mexico, just like Swainson’s Thrush that breed in Manitoba or Maine. All are similar in shape to a robin, but smaller. Smaller than an American Robin; larger than a White-throated Sparrow. This species' body mass can range from 23 to 45 g (0.81 to 1.59 oz). It is a member of genus Catharus and is typical of it in terms of its subdued coloration and beautiful, ascending flute-like voice. The IUCN Red List of Threatened Species 2016: e.T103881682A94170877. The coastal subspecies migrate down the Pacific coast of North America and winter from Mexico to Costa Rica, whereas the continental birds migrate eastwards within North America (a substantial detour) and then travel southwards via Florida to winter from Panama to Bolivia. This thrush has the white-dark-white underwing pattern characteristic of Catharus thrushes. It has also occurred as a vagrant in northeast Asia.[3]. On migration, particularly in fall, they also eat small fruits such as wild cherries and Virginia creeper. These birds migrate to southern Mexico and as far south as Argentina. In the Rocky Mountains and in Pacific states, look for them in dense alder thickets along streams running through coniferous forest. This species is 16–20 cm (6.3–7.9 in) in length. Adults are brown on the upperparts. Swainson’s Thrush is a common species, but has been gradually declining across its range; experiencing a loss of about 38% between 1966 and 2014, according to the North American Breeding Bird Survey. This is a forest bird, rarely found far from closed-canopy forest. [7] Swainson's thrushes mainly eat insects, fruits and berries. The specific ustuatus is Latin for "burnt", from urere, "to burn".[2]. The Cornell Lab will send you updates about birds, birding, and opportunities to help bird conservation. Note strong buffy eyering and lores, creating "spectacled" look, as well as buffy wash on breast. They have pink legs and a light brown eye ring. Not as the crow flies: a historical explanation for circuitous migration in Swainson's thrush (, Seasonal migration, speciation, and morphological convergence in the avian genus,, Native birds of the Northwestern United States, Creative Commons Attribution-ShareAlike License, Winker, Kevin & Pruett, Christin L. (2006): ", This page was last edited on 18 September 2020, at 07:02. BirdLife International. [4][5][6] This thrush has the white-dark-white underwing pattern characteristic of Catharus thrushes. Their fairly long wings and medium-length tail … These medium-brown birds with pale underparts have spotted chests and large buffy eyerings that extend in front of the eye, creating “spectacles.” The whitish throat is bordered on each side with a dark brown stripe. Olive-backed Swainson’s Thrush spend the winter in tropical forests of northern South America. Although Swainson's Hawk is big enough to prey on rodents, snakes, and birds (and does so, while it is raising young), at most seasons it feeds heavily on large insects instead. Possibly, the latter species adapts more readily to human encroachment upon its habitat. Males and females appear similar in most species. Four subspecies are recognised, Cathartus ustulatus alame, C. u. swainsoni, C. u. ustulatus and C. u. oedicus. Individuals breeding in the eastern and northern parts of North America (often called “Olive-backed Thrush”) are more olive-brown above with darker spotting on the breast. Size & Shape Swainson’s Thrushes are medium-sized thrushes—slim songbirds with round heads and short, straight bills. Swainson’s Thrushes breeding on the Pacific slope of the U.S. and Canada have warmer brown upperparts (see Regional Differences). Birds in the east are more olive-brown on the upperparts; western birds are more reddish brown. Swainson's thrush is a very rare vagrant to western Europe. Details of the molecular genetic analysis support the hypothesis of rapid expansion of both coastal and continental populations. Breeds primarily in evergreen forests except in California where it also uses deciduous forests near streams. Swainson's Thrush. Swainson's Thrush is best distinguished from all other thrushes by presence of buffy eye-ring and lores. Catharus ustulatus . Swainson's thrush (Catharus ustulatus), also called olive-backed thrush, is a medium-sized thrush. The widespread eastern and northern form (often called “Olive-backed Thrush”) is common east of the Cascades/Sierra Nevada. [8] They make a cup nest on a horizontal tree branch. White underparts with brownish spotting on the throat and breast. The breeding habitat of Swainson's thrush is coniferous woods with dense undergrowth across Canada, Alaska, and the northern United States; also, deciduous wooded areas on the Pacific coast of North America. Breeding habitat is a mix of deciduous and coniferous forest (though sometimes includes pure deciduous forest). At least in the winter quarters, Swainson's thrush tends to keep away from areas of human construction and other activity. This bird's song is a hurried series of flute-like tones spiralling upwards. 2016. The Swainson's Thrush is a shy ground-foraging songbird that is present in Tennessee only as a migrant. The underparts are white with brown on the flanks; the breast is lighter brown with darker spots. CS1 maint: multiple names: authors list (, Out of the wide range of fruit eaten by this bird, those of,, "Foraging behavior of Swainson's Thrushes (Catharus ustulatus) during spring migration through Arkansas". This slim and graceful hawk is a common sight over grasslands of the Great Plains and the west, but only in summer: every autumn, most individuals migrate to southern South America. The current migratory routes of the continental birds, especially the western populations, are not optimal in ecological terms, and presumably represent an inherited, historical route pattern that has not yet adapted to the birds' modern population locations. There is a small area of overlap in the Coast Mountains. Get Instant ID help for 650+ North American birds. Their fairly long wings and medium-length tail can make the back half of the bird appear long. Swainson’s Thrush breed in northern hardwood forests of New England, too, but are far more common in the high-elevation forests of spruce and fir at elevations between 1000 and 1200 meters. The potential of fruiting trees to enhance converted habitats for migrating birds in southern Mexico. All three - the Swainson's Thrush, the Veery, and the Hermit Thrush - have solid brownish upperparts (back, wings, and tail), light-colored bellies, whitish eye-rings, and varying degrees of spotting on their breasts. See more images of this species in Macaulay Library. Swainson’s Thrushes that breed in the Pacific states (often called the “Russet-backed” Thrush) are rusty-brown above, with thinner, paler eyerings and medium-brown chest spotting. Swainson’s Thrushes are shy but vocal birds that skulk in the shadows of their generally dark forest-interior habitat. Recent molecular systematics work[9] confirms that these two pairs of subspecies form two genetically distinct clades, referred to as the continental and coastal clades, which diverged during the Late Pleistocene era, probably about 10,000 years ago as the last ice age came to its end and habitats shifted across North America. They forage for insects and other arthropods on or near the ground. Individuals breeding in the Pacific states (often called the “Russet-backed” Thrush) are rustier above, with thinner, paler eyerings and medium-brown chest spotting. It frequents moist woodlands and during the non-breeding season you are more likely to hear its call note, which sounds like a drop of water, than its ethereal flute-like song. Swainson's thrush was named after William Swainson, an English ornithologist. Subspecies Cathartus ustulatus alame and C. u. swainsoni summer east of the British Columbian Coast Mountains, the Cascades and the Sierra Nevada, and C. u. ustulatus and C. u. oedicus summer west of these ranges.