Family Thrushes (Turdidae)

Least Concern

Swainson's Thrush (Catharus swainsoni)


Taxonomy

French: Grive à dos olive German: Swainsonmusendrossel Spanish: Zorzalito de Swainson
Other common names: Olive-backed Thrush
Taxonomy:

Turdus Swainsoni

Tschudi

, 1845,

Carlton House, Saskatchewan

.

Until recently considered conspecific with C. ustulatus, but differs in its olive- vs russet-toned upperparts (1); slightly brighter, bolder markings on face and breast (1); slightly shorter tail (mean 70·1 mm vs 73 in males#R; allow 1); slightly longer wing (mean 100·9 vs 97·8 in males#R; allow 1); song without the 2–3 almost identical initial notes (2); and alarm call a “quit-BRRR” vs “wee-BRRR”, with shorter length of initial note and faster pace of trilled part (at least 1)#R; moreover, present species forms a narrow (66–97 km) hybrid zone with C. ustulatus#R, within which selection against offspring is moderately strong#R. Three subspecies recognized.

What do (1) and (2) mean? Learn more about the scoring system.
Subspecies and Distribution
  • C. s. incanus (Godfrey, 1952) – C & E Alaska and NW Canada; non-breeding Colombia and Venezuela S to Peru.
  • C. s. swainsoni (Tschudi, 1845) – SW (except the coast), C & E Canada and N & WC USA; non-breeding W South America S to Argentina.
  • C. s. appalachiensis Ramos, 1991 – NE USA S to West Virginia; non-breeding Andes from Colombia S to NE Peru.
  • Descriptive notes

    16–20 cm; male 25–43 g, female 25–37 g. Medium-sized thrush with brownish-olive to greyish-olive upperparts; whitish belly and lower breast; buffy upper... read more

    Voice

    Advertising song by male only, typically at dawn and dusk from exposed perch in middle to upper... read more

    Habitat

    Mainly coniferous forests of spruce-fir (Picea-Abies), cedar-hemlock (Thuja... read more

    Food and feeding

    Invertebrates and fruit, former mainly in spring (92%) and summer, latter mainly in autumn (64%) and winter. Invertebrate prey largely... read more

    Breeding

    Eggs typically laid from mid-May to mid-Jul, the later ones probably resulting from failures during incubation; no firm evidence of double-... read more

    Movements

    Long-distance migrant; entire population migrates to South America (south to c. 31°S in... read more

    Status and conservation

    Not globally threatened (Least Concern). Generally abundant, widespread but declining species. Population of Maritime Provinces of Canada (New Brunswick, Nova Scotia and... read more

    Recommended citation

    del Hoyo, J., Collar, N. & Marks, J.S. (2019). Swainson's Thrush (Catharus swainsoni). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from https://www.hbw.com/node/1344017 on 18 August 2019).