rockfowl, either of the two species of western African birds, genus Picathartes, constituting the subfamily Picathartinae, of uncertain family relationships in the order Passeriformes. Both species, with virtually no feathering on the head, have drab, grayish plumage and are thin-necked, hump-backed, and heavy-billed—quite vulture-like in appearance. In the white-necked rockfowl (Picathartes gymnocephalus), 48 centimetres (19 inches) long, found from Sierra Leone to Togo, the head skin is yellow and black; in the gray-necked rockfowl (P. oreas), 40 cm (15 1/2 in.) long, of Cameroon, it is red and gray-blue. Rockfowl search the ground for insects, snails, crustaceans, and small vertebrates in wet, rocky upland forests. They make mud nests in colonies on cliffs.