Habitat
Blue-black Grassquits inhabit grassy, weedy, and shrubby fields; open thickets; field edges; and roadside vegetation. They are most common in lowlands, less common in foothills, and can occur up to 2,600 meters (8,500 feet).
Back to topFood
Blue-black Grassquits feed mostly on the seeds of grasses, foraging on the ground and also picking seeds from grass heads. They also eat small amounts of insects and berries.
Back to topNesting
Nest Placement
Both sexes build the nest, placing it within a meter (3 feet) of the ground in grasses or a low bush.
Nest Description
A small, thin cup built with grasses and fibers and lined with spiderwebs and fine roots.
Nesting Facts
| Clutch Size: | 2-3 eggs |
| Number of Broods: | 1-3 broods |
| Nestling Period: | 9 days |
| Egg Description: | Bluish-white, with brownish or purplish spots concentrated on the larger end. |
Behavior
Male Blue-black Grassquits perform frequent display flights—sometimes several per minute—from conspicuous low perches. A male jumps up about 30 cm (1 foot) from the perch, flaps his wings six or more times (revealing white underwing patches), and then sings just before landing. During the breeding season grassquits occur in pairs, but at other times they gather in flocks (sometimes quite large) and often associate with other seedeating species.
Blue-back Grassquits are generally monogamous, but extra-pair matings are also common. Both members of a pair build the nest and feed the nestlings, which fledge after about 9 days.
Back to topConservation
The International Union for Conservation of Nature lists Blue-black Grassquit’s conservation status as Least Concern, due to an extremely large range, increasing population trend, and extremely large population size (estimated at 50 million mature individuals).
Back to topCredits
BirdLife International. 2021. Volatinia jacarina. The IUCN Red List of Threatened Species 2021: e.T22723396A167752553. https://dx.doi.org/10.2305/IUCN.UK.2021-3.RLTS.T22723396A167752553.en.
Carvalho, C.B.V., Macedo, R.H.F. and Graves, J.A. (2007). Reproduction of Blue-black Grassquits in central Brazil. Braz. J. Biol.. 67(2): 275-281.
Fandiño-Mariño, H. and Vielliard, J.M.E. (2004). Complex communication signals: the case of the Blue-black Grassquit Volatinia jacarina (Aves, Emberizidae) song. Part I - A structural analysis. An. Acad. Bras. Ciênc. 76(2): 325-334.
Howell, S. N. G., and S. Webb (1995). A Guide to the Birds of Mexico and Northern Central America. Oxford University Press, New York, NY, USA.
Ridgely, R. S., J. A. Gwynne, G. Tudor, and M. Argel (2016). Birds of Brazil: The Atlantic Forest of Southeast Brazil including São Paulo and Rio de Janeiro. Cornell University Press, Ithaca, NY, USA.
Rising, J. D. (2020). Blue-black Grassquit (Volatinia jacarina), version 1.0. In Birds of the World (J. del Hoyo, A. Elliott, J. Sargatal, D. A. Christie, and E. de Juana, Editors). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.blbgra1.01
Schulenberg, T. S., D. F. Stotz, D. F. Lane, J. P. O’Neill, and T. A. Parker (2007). Birds of Peru. Princeton University Press, Princeton, NJ, USA.