Forbes's blackbird is an average sized icterid around 21–24 cm with all black, non-glossy feathers.

Forbes's blackbird is a non-migratory species found in east and north-east Brazil in small and very fragmented habitats.

It has been found in small numbers around sugar cane plantations and pastures adjacent to forest patches and marshy areas.

Much of the destroyed forest has been converted to sugar cane plantations which the local populations may be able to withstand.

Decline in population size has also been attributed to reduced reproductive success due to brood parasitism from the shiny cowbird (Molothrus bonariensis).

At Pedra Telhada experiments are being performed on destroying shiny cowbird eggs that have parasitized blackbird nests.