Violet-green Swallow (Tachycineta thalassina) [XC72211]
by Richard E Webster from Observatorio area, Sierra San Pedro Martir, Baja California, Mexico (flight call)
Violet-green Swallow (Tachycineta thalassina) [XC741542]
by Logan McLeod from Okanagan-Similkameen H (near Manning Park), Okanagan-Similkameen, British Columbia, Canada (begging call)
Subspecies
Closely related to Golden Swallow (Tachycineta euchrysea) and Bahama Swallow (Tachycineta cyaneoviridis). Population from Alaska and Canada south to Arizona, New Mexico and Baja California sometimes treated as separate subspecies lepida.
The following 2 subspecies are recognised:
thalassina (Swainson, 1827) - Central Alaska and western Canada (southern from northern Yukon, south-western Mackenzie, northern British Columbia, west-central Alberta, south-western Saskatchewan) southern in western USA (east to western North Dakota and north-western Nebraska) to southern Arizona and southern New Mexico, and Mexico (south to central Baja California, also on plateau south to Oaxaca and Veracruz). Winters Baja California south to Costa Rica.
BirdLife International Species Factsheet