The Black-headed Antthrush is a member of the genus Formicarius, which are chunky, forest floor dwelling birds, related to antpittas, but are shaped somewhat like rails, with short, stubby tails, and walk like a chicken. The Black-headed is found in a narrow elevational belt along the Caribbean foothills of Costa Rica and Panama, and in the lowlands and lower Andean foothills along the Pacific slope of Colombia, south to northwestern Ecuador. Rather similar in plumage to the more widespread Black-faced Antthrush (Formicarius analis), but has entirely grayish-black breast, neck, and head, as opposed to the black being limited to the throat and face in Black-faced. It is similar to most other Formicarius species in having blue bare skin around the eye. Replaced at higher elevations through much of its range by Rufous-breasted Antthrush (Formicarius rufipectus). Antthrushes are typically heard much more often than seen. The song of Black-headed is typically a series of 15-30 clear, ringing notes that both speeds up and rises in pitch at the end. It differs greatly from other similar species, in particular the Rufous-breasted Antthrush which has a two-note whistle song “tuu-tuu.” Usually occurs as singles or pairs in the forest, but sometimes found attending army ant swarms.