Black-chinned Antbird

The black-chinned antbird is 11 to 12.2 cm (4.3 to 4.8 in) long and weighs about 12 to 18 g (0.42 to 0.63 oz). Adult males have leaden gray upperparts. Their tail is slate gray with narrow white feather tips. Their flight feathers are leaden gray with lighter gray edges and their wing coverts are black with gray and white edges. Their throat is black. Their underparts are mostly a paler gray than their upperparts and with a grayish white belly. Adult females have the same leaden upperparts as males. Their throat is whitish with black and gray speckles. Their breast is mottled with gray and white and an olive gray tinge. Their sides and flanks are grayer than their breast, and their belly and undertail coverts are gray tinged with buff. Both sexes have a gray iris and blue-gray legs and feet. Males have a black bill; females have a black maxilla and a gray mandible. Subspecies H. m. melanopogon sensu lato and H. m. minor have essentially the same plumage. The putative subspecies H. m. occidentalis is described as having a smaller black throat patch and paler underparts with more gray spotting than H. m. melanopogon sensu stricto.

Under the two-subspecies model, the nominate black-chinned antbird is found from eastern Colombia east through southern and eastern Venezuela and the Guianas to the Atlantic in northeastern Brazil and south into far northeastern Ecuador, northeastern Peru, and Brazil north of the Amazon. The IOC places occidentalis in "Colombia, Venezuela and nw Brazil", melanopogon in "the Guianas and n Brazil", and makes no mention of Ecuador or Peru. Hilty places occidentalis in southwestern Venezuela and melanopogon in northeastern and east-central Venezuela. He notes that the species' range extends into Colombia, Ecuador, Peru, the Guianas, and Brazil without differentiating which subspecies is where. All relevant sources agree that subspecies H. m. minor is found in south-central Amazonian Brazil south of the Amazon between the Purus and Tocantins rivers. The black-chinned antbird inhabits lowland evergreen forest, almost always in várzea forest along larger rivers, along smaller watercourses, and along the edges of lakes. It favors low vegetation that overhangs water. In elevation it reaches 450 m (1,500 ft) in Venezuela, 500 m (1,600 ft) in Colombia, and 200 m (700 ft) in Ecuador.

The black-chinned antbird's diet has not been detailed but is known to be mostly insects and to include spiders. Pairs and family groups forage mostly on the ground and up to about 2 m (7 ft) above it, and almost always near or even over water. They actively hop on the ground and through vine tangles and brush. They capture prey by gleaning and reaching and with short sallies from a perch. They occasionally attend army ant swarms.