Sooretama Slaty-Antshrike Thamnophilus ambiguus Scientific name definitions

The Sooretama Slaty-Antshrike is a fairly common endemic of coastal eastern Brazil, where it occurs in the understory and midstory of lowland evergreen forest and its edges, as well as in sandy-soil woodland and tall scrub, from the state of Sergipe south to at least Rio de Janeiro. Most easily detected by virtue of its accelerating loudsong, which sounds similar to that of the almost wholly allopatrically distributed Planalto Slaty-Antshrike (Thamnophilus pelzelni); the latter replaces the present species over the interior of eastern Brazil. These two species differ only subtly in plumage too, but there is no suggestion of intergradation between them in their contact zone, in parts of Bahia and probably Minas Gerais. The behavior of the Sooretama Slaty-Antshrike apparently closely recalls that of other slaty-antshrikes. This antshrike takes its unusual vernacular name from the famous Sooretama Biological Reserve, which serves as an important focal point for the conservation of lowland east Brazilian avifauna, and wherein the present species is easily found.

SE Brazil in coastal region from S Sergipe S to Rio de Janeiro, extending inland in Minas Gerais (R Doce Valley); one probable sight record in extreme NE São Paulo.

Loudsong an accelerating series of rather harsh, dry notes (e.g. 20 notes, 5 seconds) ending with short roll, mostly even in pitch but rises slightly at start and sometimes falls slightly at end; rattle a rapid repetition of abrupt notes very variable in length and pace, short rattles tend to drop in frequency, longer rattles flatter. Calls include “caw” note, variable in length, typically downward-inflected, usually given singly, and more complex complaining note; also downward-inflected short growl, like a raspy “caw”.