Planalto Slaty-Antshrike

14 cm. This species and /Thamnophilus ambiguus were recently split. Although very similar they are differentiable in the males by the color of the belly and in the females by the color of the mantle. <NMale grayish above with a black crown. The forecrown is uniform grayish more blackish streaked in ambiguus . The back is gray with some mixed black and gray plumage more gray in ambiguus . Scapulars and wing-coverts black, boldly spotted white. Wings black, the primaries and secondaries edged white. Tail and rump feathers black with white tips. Below slate-gray with a whitish belly grayish belly in ambiguus . <N Females are reddish-brown above olive-brown in ambiguus with a rusty-brown crown both forms . Wings and tail as in the male. Below pale olive-brown, more ochraceous in pelzelni. Voice | The songs of pelzelni and ambiguus are hard to distinguish. 15-17 rapid notes terminate in a trill or roll "wak wak wak wak wak wak wakwak wakwakwakwkwkwkwkwkwk" rising somewhat in pitch. Isler et al suggest that it is possible to ascribe a song to either pelzelni or ambiguus by measuring the time of delivery of the first five notes. In pelzelni these are delivered in about 0.6 sec, in ambiguus in about 0.9 sec. However they report overlap in the characteristics of these songs suggesting that the best criterion for one or the other taxon is geographical distribution. Call a "grrrr" ^30 and a "cow" ^57 . Behaviour | Forages low and concealed. Quivers its tail when calling. Breeding | In scrub and woodland borders, caatinga, secondary forests. Range | On the Brazilian Plateau in Estado de S<C4>o Paulo Bauru, Franca, Bebedouro, S<C4>o Jeronimo ;^40= , Minas Gerais, and might be found inland closer to the coast in suitable habitat. Up to 1000 meters. On the basis of morphological differences the Thamnophilus punctatus complex was recently split into six allopatric species ^57 . These allopatric populations were considered to be full species even in the absence of discernible vocal differences, because the lack of clinal intermediary morphological characteristics of the populations at the contact zones suggested an absence of gene flow.<N 3888 Song, Pirapora, Minas Gerais, 11<10>12<10>98. Cloudy, 25<91>C. Gallery forest, scrub: 8173 Song, Pirapora, Minas Gerais, 11<10>13<10>98. Cloudy, 30<91>C. Scrub.: 11343 >. Male: 662 >. Female.