Their bills are of medium thickness, thinner than those of seed-eaters and thicker than those of insectivores. Adult males are bright yellow and black, with orange-red heads. All plumages are mostly yellow, with dark tails and two wing-bars on each wing. The dark markings are solid black on mature males and gray to brown on females and juveniles. Males have one white and one yellow wing-bar on each wing. Both wing-bars may be white, or one may be pale yellow on females, which are duller yellow than males. First-year males have little or no red on their heads.