Blue black grassquit

The blue-black grassquit (Volatinia jacarina) is a small bird in the tanager family, Thraupidae. It was previously classified in the bunting and American sparrow family, Emberizidae. It breeds from southern Mexico through Central America, and South America as far as northern Chile, Argentina and Paraguay, and on Trinidad and Tobago. It is the only member of the genus Volatinia.

Adult blue-black grassquits are 10.2 cm (4.0 in) long and weigh 9.3 g (0.33 oz). They have a slender conical black bill. The male is glossy blue-black, with a black tail and wings; the white inner underwing is visible in flight or display. Female and immature birds have brown upperparts and dark-streaked buff underparts.

The male has a jumping display, often performed for long periods, which gives rise to the local name "johnny jump-up". This is accompanied by a persistent wheezing jweeee call.

This is a common bird in semi-open areas, including cultivation and gardens. It makes a small cup nest, with a typical clutch of one to three pale green eggs blotched with reddish brown. Both sexes incubate for 9–10 days, with about the same period again for the young to fledge.

The blue-black grassquit feeds mainly on seeds. It is quite gregarious and forms communal evening roosts.