Violet-green swallows are secondary cavity nesters, found in a number of habitats including deciduous and coniferous forest.

(13 cm), the violet-green swallow is slightly shorter and appears more compact in flight compared to other members of the family Hirundinidae.

The species is best identified by the glossy green on the top of the head and back as well as hints of purple on the nape, rump and upper tail.

However, the more gradual change in colour and visible (but slightly reduced) white cheek patches can help identify juvenile individuals of the species.

[3]Violet-green swallows are important members of the Tachycineta clade due to their large geographic range and because they are one of 2 species that breed within North America.

It is generally agreed that Tachycineta is split into a North and a South American clade, but the phylogenetic placement within the genus depends on the type of analysis used.

[3][4] Nuclear genome analyses and a consensus of both methods have reorganized this North American clade, alternating the closest sister taxon of T. thalassina between T. cyaneoviridis and T.

Violet-green swallows are divided into three subspecies, T. t. thalassina, T. t. brachyptera and T. t. lepida differing in breeding ranges and wing length.

Longitudinally, the range borders the west coast of Alaska, British Columbia and the United States, and extends eastward into southwestern Alberta, Montana, the Dakotas and Texas.

[11]Observations of violet-green swallows making twitter calls typically associate the vocalization with courtship displays and the establishment of new territories.

The examination of the stomach contents of multiple individuals has presented a wide range of diet items, including insects like ants, beetles and flies as well as other arthropods such as spiders.

Location dependent, copulation takes place mid-May with the eggs being laid by the start of June, followed by a couple weeks of incubation before hatching.

[17][19] A similar field observation notes a violet-green swallow laying an egg in an active bluebird nest box.

It appeared the bluebirds tolerated the act of egg-dumping by the violet-green swallow, but the observer returned the following day to find the newly laid egg smashed below the nest.

This behaviour suggests that when unable to access her original nest after physiologically committing to laying her egg, a female violet-green swallow may participate in interspecific egg-dumping.

[17]Violet-green swallows are secondary cavity nesters and aerial insectivores, making males susceptible to nest and mate competition.

Despite too small of a sample size to hold statistical significance, fledgling survival was greater when violet-green swallows provided active care.

After multiple aerial battles, the chickadees regained control of their nest and successfully defended against future violet-green swallow attacks.

Few observations of this decrease in body temperature and metabolic rate have been recorded in violet-green swallows, the first case occurring in 1965 near Death Valley National Monument in Saratoga Springs, California.

The physical appearance of the swallows, including the position of their head in relation to the slope and the fluffing of their feathers was similar to that of other birds in torpor.

[22] In addition to reaching borderline hypothermic temperatures during bouts of torpor,[22] violet-green swallows have been observed behaving similar to hyperthermic individuals while sunbathing.

The period of sunbathing in violet-green swallows is short and dependent on ambient temperature and wind velocity, but typically occurs after an increase in parasite loads near the end of nesting.