Mato Grosso Antbird Cercomacra melanaria Scientific name definitions

The Mato Grosso Antbird is common in the pantanal region of Mato Grosso, Brazil, but the distribution extends west to north central Bolivia, and it also occurs in far northern Paraguay. In general appearance, this antbird is a typical Cercomacra: medium sized, with a graduated tail and a fairly long, slender bill. The male is mostly black, with white-tipped wing coverts and white tips to the rectrices; the male is very similar to several other species in the genus, especially to the Rio Branco Antbird (Cercomarca carbonaria), the Jet Antbird (Cercomacra nigricans), and the Bananal Antbird (Cercomacra ferdinandi). All of these species are distributed around the edges of Amazonia, and do not overlap geographically with each other. The female is mostly gray-brown, paler on the underparts, but with the wing and tail pattern as in the male. Mato Grosso Antbirds typically forage as pairs in the under- and midstory of thickets in gallery forest and the edge of deciduous forests.

C & E Bolivia (Beni, Cochabamba, Santa Cruz), extreme N Paraguay (Alto Paraguay) and SC Brazil (S Mato Grosso, W Mato Grosso do Sul).

Male loudsong 3 buzzy notes, first one abrupt, second long, third intermediate in length, sometimes repeated in short sequences; female nearly identical but higher-pitched; synchronized duet initiated when female interjects loud clearer note during male loudsong, at which point male shifts to similar single clearer note, lower-pitched than female’s, the two notes alternated antiphonally for 3–5 seconds. Notes sometimes repeated in doublets, presumably as call.

In a study in the Brazilian Pantanal (2 Bernardon, B., Albonette de Nóbrega, P.F. and de Pinho, J.B. (2014). Reproductive biology and nest-site selection of the Mato Grosso Antbird Cercomacra melanaria in the Brazilian Pantanal. Revista Brasileira de Ornitologia. 22(3): 270–277. Close ), laying was mainly in Oct–Nov; nests, found in sites with relatively dense vegetation, where low cups placed inside shrubs or trees at 0·2–4·5 m above the ground (0·98 m on average, n = 51), constructed with fine fibers derived mainly from aerial roots of Cissus spp. and dried leaves of Licania parviflora, and secured with spider webs; clutch, 2 eggs (1·9 eggs on average, n = 34); eggs, 20·9 mm × 15·1 mm, 2·5 g (n = 30); incubation period c. 14 days, and nestling period 8–11 days (9·4 on average, n = 10); both males and females participated in nest construction, egg incubation, and feeding of nestlings; two adult females were preyed upon in their nests, probably during the night.

Not globally threatened (Least Concern). Locally common, particularly in vast areas of Brazilian and Bolivian Pantanal. Only part of Pantanal is formally protected, but nature of seasonal flooding cycles in region provides some natural buffer to human disturbance. A number of proposed hydro-electric schemes, if instituted, could pose significant threat to the general ecosystem of the Brazilian Pantanal.