Blue-black Grassquit

The blue-black grassquit, Volatinia jacarina, is a diminutive and vibrant member of the tanager family, Thraupidae. Exhibiting sexual dimorphism, the male is adorned in a glossy blue-black plumage with a hint of white under the wings, while the female is cloaked in a more subdued brown with pale buff and darker streaks below.

Identification Tips

When identifying the blue-black grassquit, look for the male's striking blue-black sheen and the white patches under the wings, which are particularly visible during flight or display. Females and juveniles can be recognized by their brown upperparts and the dark-streaked buff underparts. Both sexes possess a slender, conical black bill.

Habitat

This species is typically found in open and semi-open areas where grasses are prevalent.

Distribution

The blue-black grassquit has a broad range, extending from southern Mexico through Central America, and across South America to northern Chile, Argentina, and Paraguay. It is also present in Trinidad and Tobago. A rare sighting was recorded in Graham County, Arizona in July 2023.

Behaviour

The blue-black grassquit is known for its unique breeding displays, where the male performs an energetic jumping display, colloquially known as "johnny jump-up." This display is often accompanied by a persistent wheezing call. Outside of the breeding season, these birds may gather in flocks.

Song & Calls

The male's display is accompanied by a distinctive wheezing 'jweeee' call.

Breeding

These birds are socially monogamous, with a breeding season characterized by males defending small territories. The nests are small cups made of rootlets, situated in herbaceous vegetation. Both sexes contribute to the construction of these nests.

Diet and Feeding

Primarily seed eaters, blue-black grassquits forage mostly on the ground.

Conservation status

The blue-black grassquit is currently listed as Least Concern on the IUCN Red List, indicating a stable population without significant threats at this time.