Violet-Green Swallow

Tachycineta thalassina

The Violet-Green Swallow breeds in western North America from Alaska to Mexico. They spend winters in Central and northern South America. Some populations never leave Mexico. They nest in cavities in a tree or rock crevice, sometimes forming small colonies. I once found a pair nesting in a shallow burrow on a dirt bank in the Yukon.

If we held a beauty contest, and the contestants were all swallows, the Violet-Green Swallow would probably get the most votes. Viewed at a distance, and on the wing, we might confuse them with Tree Swallows, the likely runner-up in our fictitious contest. I try to look at the white band near the bird’s rump. The Tree Swallow’s band falls far short of a full circle over the top, while the Violet-Green Swallow’s is nearly complete.

There has been a slight decline in population for these birds, as with most aerial insectivores. Use of insecticides is the suspected cause for this decline.

Today, researchers recognise two subspecies of Violet-Green Swallow:

• T. t. thalassina breeds in Alaska, Canada, and in the western USA, south to Arizona, New Mexico, and Mexico. They spend winters from Baja California (Mexico) to Central America.
• T. t. brachyptera breeds in northwestern Mexico, in Baja California and Sonora.