Half-collared Sparrow

The half-collared sparrow (Arremon semitorquatus) is a species of bird in the family Passerellidae, the New World sparrows. It is endemic to Brazil. == Taxonomy and systematics == The half-collared sparrow was formally described in 1838 with its current binomial Arremon semitorquatus. It was long treated as a subspecies of the pectoral sparrow (A. taciturnus) but was again elevated to full species status in the early 2000s. The two are sister species. The half-collared sparrow is monotypic. == Description == The half-collared sparrow is about 15 cm (5.9 in) long and weighs 22 to 28 g (0.78 to 0.99 oz). The species is sexually dimorphic but not dramatically so. Adult males have a black crown with a gray stripe through its middle, black lores, and a white supercilium that extends to the nape. The rest of their face is black. Their nape and the sides of their neck are gray. Their upperparts, wings, and tail are mostly greenish olive with somewhat more yellowish green on the lesser wing coverts. They have a white throat. Their underparts are mostly white with a black patch on the side of the upper breast and gray flanks. Adult females have a similar pattern to…