Sounds and Vocal Behavior

Vocalizations

Across the wide geographic range of Black-faced Antthrush, the primary song begins with a single, sharp note, but the remainder of the song varies geographically, with pitch, note number, and cadence differing markedly. Beginning in the early 1970s (e.g., Davis 1972), field ornithologists noted there were three distinct song types in Black-faced Antthrush:

The song of birds in the northern moniliger Group begins with a sharp introductory whistle at ca 2.0 kHz followed, after a short pause, by a series of 8–12 whistles on roughly the same pitch but that increase in volume.

The song of birds in the southern analis Group is broadly similar—particularly the sharp introductory whistle at ca 2.0 kHz followed by a pause—but the series of 8–15 whistles is more compressed and variable, so that the birds sing a sputtering, rising and falling trill from ca 2.2 kHz to ca1.9 kHz.

By contrast, the song of birds in the central hoffmanni Group begins with a sharp introductory whistle at ca 2.0 kHz, followed by a slow series of 2–4 sharp whistles at ca 1.8 kHz. On rare occasion birds in the hoffmanni group utter up to 10 sharp whistles after the introductory note, but relative to birds in the northern group these whistles are spaced widely and pitched lower than the first.

Songs in geographically isolated populations in northeastern Venezuela—the Unare Depression east through the Paría Peninsula—and on adjacent Trinidad do not fall neatly into any of three clearly defined song types. These songs are least like those of the moniliger group, but in some respects they are intermediate between songs of the hoffmanni and analis groups, in that they give one to four monotonically descending notes after the introductory note, and birds on Trinidad do likewise (personal observation, June 2008). Songs with only a single note after the introductory one closely resemble the song of Chestnut-backed Antbird (Myrmeciza exsul). Many songs have 2–3 trailing notes, as is in songs of the hoffmanni Group, but these trailing notes have a shorter cadence and change in pitch, as in songs of the analis Group.

In the moniliger Group, song differs enough among individuals that individuals can be identified statistically with a high degree of correct classification (Kirschel et al. 2009). The extent of individual variation in the other subspecies groups is unknown, but it is likely to be appreciably similar, especially in the analis Group.

The alarm call is a sharp tleet, often doubled (Skutch 1945). The call is delivered most often when a bird is flushed or startled. This call appears to be invariant across the species range, although no one has examined geographic variation in this vocalization.

Development

No information.

Black-faced Antthrush snaps its bill in agonistic interactions (Willis 1985).