Pithys

Pithys is a genus of insectivorous passerine binds in the antbird family (Thamnophilidae) found in the lowland forests of South America. The genus includes two species: Pithys albifrons (White-plumed Antbird) and Pithys castanea (White-masked Antbird). These birds are known for their association with army ant swarms, which they follow to catch insects and other small animals that flee the swarm. This specialized feeding behavior, known as obligate ant-following, is rare among birds and defines much of the genus’s ecology.

Pithys albifrons is about 12 cm in length. It is smaller than most species of its family, weighing 26 grams on average. This bird has a chestnut-colored underside, dark bluish-gray upperparts, and upright white feather tufts above the eyes and on the chin. The crown and throat are black, and the face shows narrow white stripes above the eyes. The legs are yellowish-orange. Young Pithys lack the white plumes and have duller plumage overall. This species is typically found in dense understory and can be observed darting to the ground during foraging. Its vocalizations include a high, falling “tjeeeew” song and a sharp “sreew” or “churr” call, which it uses frequently at active ant swarms.