Swainson's Thrush (Catharus ustulatus) [XC575514]
by Steve Hampton from Provo River Valley, Wasatch County, Utah, United States (call)
Swainson's Thrush (Catharus ustulatus) [XC812152]
by Richard E. Webster from Municipality Of Leamington (near Wheatley), Essex County, Ontario, Canada (nocturnal flight call)
Subspecies
Formerly placed in Hylocichla, along with Veery (Catharus fuscescens), Grey-cheeked Thrush (Catharus minimus), Bicknell's Thrush (Catharus bicknelli) and Hermit Thrush (Catharus guttatus). Subspecies fall into two groups, russet-backed "nominate group" (also with phillipsi and oedicus) and olive-backed "swainsoni group" (also with incanus and appalachiensis); these differ not only in morphology but also in breeding habitat, certain vocalizations and wintering areas, but separate species status for the two has not, apparently, been mooted.
Proposed subspecies almae synonymized with nominate.
The following 6 subspecies are recognised:
incanus (Godfrey, 1952) - Central and eastern Alaska and western Canada. Non-breeding Colombia and Venezuela south to Peru.
swainsoni (Tschudi, 1845) - Central and eastern Canada and northern USA. Non-breeding South America. Considered by some authors to be a distinct species, Swainson's Thrush (Catharus swainsoni).
appalachiensis Ramos, 1991 - Eastern USA. Non-breeding Colombia south to north-eastern Peru.
ustulatus (Nuttall, 1840) - Pacific coast from south-eastern Alaska south to northern California and northern New Mexico. Non-breeding Mexico south to Panama.
phillipsi Ramos, 1991 - Queen Charlotte Is (western Canada). Non-breeding eastern and western Mexico.
oedicus (Oberholser, 1899) - South-western USA (California). Non-breeding western Mexico south to Nicaragua.
BirdLife International Species Factsheet