Medium-sized, finch-like bird with long tail and strong, sturdy bill. Males have uniformly black plumage and impressively large contrasting white bill, while the females are brownish with dusky, blackish bill. Size and shape similar to Chestnut-bellied Seed-finch, but note larger size, colder brown coloration, and heftier bill. Usually alone or in pairs, rarely in isolated flocks. Uncontrolled trapping for the cage bird trade has severely threatened this species.