White-bearded Antshrike

The white-bearded antshrike (Biatas nigropectus) is a Vulnerable species of bird in subfamily Thamnophilinae of family Thamnophilidae, the "typical antbirds". It is endemic to Argentina and Brazil. == Taxonomy and systematics == The white-bearded antshrike was described by the French ornithologist Frédéric de Lafresnaye in 1850 and given the binomial name Anabates nigro-pectus. It was later moved to its current genus Biatas that was erected by the German ornithologists Jean Cabanis and Ferdinand Heine in 1860 with the white-bearded antshrike as the type species. The name of the genus is from the Ancient Greek biatas meaning "tyrant". Its specific epithet combines the Latin words niger meaning "black" and pectus meaning "breast". The white-bearded antshrike is the only member of its genus and has no subspecies. == Description == The white-bearded antshrike is 17 to 18 cm (6.7 to 7.1 in) long. This species exhibits some sexual dimorphism, and both sexes have a crest. Adult males have a black forehead, crown, and upper nape. The black of the crown extends down to the lores and eyes except for a faint white line through the eye. Their chin and the rest of their face are white that becomes pale buff around the…