The swallow tanager (Tersina viridis) is an interesting bird species that is relatively small and widespread throughout lowlands and foothills up to an altitude of 1,800 m. This species is sexually dimorphic, meaning that the males and females exhibit different physical characteristics. The males are opalescent blue with a black face and throat, while the females are bright green with dusky-olive barring on the flanks and lack the black face mask of the males. Juvenile birds look similar to the females.
Swallow tanagers are commonly found throughout South America, from Panama all the way down to Northern Argentina, and can be spotted in various habitats including forest edges, open woodlands, clearings, second growths, and other areas close to water.
These birds prefer to perch on exposed branches and feed on fruit and insects. Their diet consists of a variety of fruits, including berries and avocadoes, as well as insects such as termites, grasshoppers, and ants. They also sally out to catch insects on the wing, often taking two or three before returning to the same perch.
In terms of nesting, swallow tanagers mostly use cavities made by other birds or humans, such as cliffs, earth banks, and even bridges. The female usually lays 3 white eggs within the nest and incubates them for around 13 to 17 days. Both parents feed the young, but the female is more involved in this task than the male. The young leave the nest after approximately 24 days.
While the swallow tanager has an extremely large range and does not approach the thresholds for Vulnerable on the IUCN Red List, it is still an interesting bird to observe. You can watch and listen to this bird in the video below to appreciate its beauty and unique characteristics.