Swallow with very long wings, very noticeable in flight. It measures up to 17 centimeters and its plumage is gray, with the exception of the belly and throat, which are white. It has a gray "necklace" just below the throat, which runs in a vertical line along the belly. This species is very dependent on the Rufous Hornero, as it usually uses abandoned mud houses as a nest. Like the other swallows, it flies very nicely. It feeds on termites, bees, ants and flies, all hunted in flight. It can be seen occasionally on the Praia Vermelha Campus, next to Avenida Pasteur.