The racial differences in the female plumages are minor, with S. c. hoffmannii, S. c. hicksii and S. c. ophthalmica generally being paler and less brown than S. c. corvina, and often with a faint yellow tinge below.

Males may not acquire the full adult plumage in their first year, and may breed whilst still showing some immature features in their appearance.

Such individuals seem to provide a glimpse at the circumstances of speciation: in the genera Sporophila and Oryzoborus, several species exist which differ externally only by one having white areas, the other being hypermelanic just as the two variable seedeaters mentioned here.

Of course, there must be some factor maintaining reproductive isolation, but the plumage differences between such seedeater species pairs probably had their origin in such a mutation becoming fixed in a founder population due to genetic drift.

In large parts of Costa Rica and Panama it is impossible to clearly assign individuals to specific subspecies, where most instead show some level of intergradation between S. c. corvina, S. c. hoffmannii and/or S. c. hicksii.

This seedeater is a common to abundant bird in lowlands and foothills up to 1,500 m (4,900 ft) altitude in semi-open areas such as forest edges, roadsides, low scrub and gardens.

The flimsy cup nest, built by the female, is made of coarse plant material and lined with a few finer fibres.