This sparrow has separated populations in Cuba. The nominate form at Zapata Swamp lives in sawgrass marsh; adults have a chestnut crown and white throat, and its diet changes with the seasons.
Adults at Zapata Swamp have olive-gray upperparts, a chestnut crown, white throat, and yellowish belly. The sexes are similar in plumage.
At Zapata Swamp the nominate form uses marshes with sawgrass and other sedges, plus scattered shrubs. The report gives seeds and fruit for the dry season, insects and snail eggs for the wet season.
An extinction-risk assessment has not been added yet.