Anis are bizarre, coal-black cuckoos with long floppy tails and unique, curiously tall, flattened bills. Smooth-billed occurs in various open and semi-open habitats in tropical lowlands and foothills, typically low in shrubs and grasses. Gregarious and not particularly graceful; usually seen crashing around awkwardly in small groups. Flies with choppy wing beats and long glides. Widespread throughout much of South America and the Caribbean, extending as far west as the Pacific slope of Costa Rica and north to Florida. Compare with the very similar Groove-billed Ani, which overlaps in some areas of Central and South America. Note especially the bill shape: Smooth-billed often (but not always) has a taller ridge on the top of the bill and a sharper angle on the lower edge of the bill. The sides are typically smooth, rarely with weak grooves. Voice is also important: listen for a rising, hawklike whistle with an inflexion at the end. Dark eye, size, and habitat help separate from Greater Ani in South America and Panama.