Swallows (us-RGV)

From WikiBird

Hirundinidae

The bird family Hirundinidae is a group of passerines characterised by their adaptation to aerial feeding, and known as swallows and martins. The family comprises two subfamilies: Pseudochelidoninae (the river martins of the genus Pseudochelidon) and Hirundininae (all other swallows and martins). Within the Hirundiniae, the name martin tends to be used for the squarer-tailed species, and the name swallow for the more fork-tailed species; however, there is no scientific distinction between these two groups.

Their adaptations to hunting insects on the wing are a slender streamlined body, and long pointed wings. Like the unrelated swifts and nightjars, which hunt in a similar way, they have short bills, but a wide gape.

The feet are designed for perching rather than walking, and the front toes are partially joined at the base. Many species have long tails.

Genus: Progne