The black silhouette of an Archaeopteryx-shaped bird alternately flaps and glides on its linear route. Its whining call, “ ah-nee, ah-nee, ah-nee,” is echoed by other Smooth-billed Anis, which soon follow in single file. Such is a typical glimpse of the Smooth-billed Ani, a common resident of subtropical and tropical savannas in southern Florida, the Caribbean, and Central and South America. This member of the cuckoo family is distinguished by its all-black plumage, long tail, large beak, and distinctive call.
During the breeding season, this ani lives in pairs or more commonly in larger groups of up to 17 individuals. It is best known for its communal breeding system, in which a number of females typically lay eggs and incubate in the same nest. Late-laying females bury the eggs of early-laying females with twigs and leaves, which can create a number of layers of eggs; only the top layer eventually hatches. Depending on the size of the group, as many as 36 eggs may be found in a single nest.
This species inhabits savanna, second-growth scrubland, and disturbed areas. In Puerto Rico, breeders often choose thorned trees such as mesquite (Prosopis pallida) or guamá (Pithecellobium dulce) to nest in or for nesting material. They are mainly insectivorous, feeding on grasshoppers, caterpillars, and moths, but also taking small frogs and lizards. Fruit is an important part of their diet in the dry season. They are nonmigratory, and in seasonally dry habitats begin breeding with the onset of the rainy season, which stimulates a surge in insects. Where rainfall is less seasonal, the Smooth-billed Ani may breed year-round.
Early studies were generally descriptive and lacking in quantitative data; for example, Bent ( Bent 1940a ) in Jamaica, Koster ( Köster 1971 ) in Colombia, and Davis ( Davis 1940a ) in Cuba, Guyana, and Argentina. Study of a population in South Florida focused on group size and female reproductive tactics ( Loflin 1983 ). More recently, ongoing research by J. S. Quinn and colleagues (J. M. Startek and L. Blanchard unpubl.) have begun examining the mating system, combining field studies with the use of genetic markers ( Startek 1997 , Blanchard 2000 ).