The adult male is distinguished from the plumbeous seedeater by its larger size and bluish grey plumage, and from that and other Sporophila seedeaters, by having a robust, bright yellow beak with an arched culmen, and by vocalisations that include unique call notes.
Tropeiro seedeaters breed in upland shrubby grasslands associated with the Araucaria forests of southern Brazil. They migrate northwards to spend the austral winter – the non-breeding season – in the Cerradosavannas of central Brazil. The range contains a narrow contact zone between the Tropeiro and plumbeous seedeaters, where the birds are segregated by habitat that contains little significant gene flow.