This article is about the bird family. For the bird genus see Vireo (genus), For other uses, see Vireo (disambiguation).
Vireo make up a family Vireonidae, small and medium-sized passerine birds (mainly) limited to New World. They are typically dull-plumaged and greenish in color, smaller species resembling ratchet warblers apart from their heavier bills. They range in size from the Chocó vireo, dwarf vireo and lesser greenlit, all within 10 centimeters and 8 grams, to peppershrikes and shrike vireos at up to 17 centimeters and 40 grams (Forshaw & Parkes 1991).
Distribution and habitat
Most of the species are found in Mid-America and northern South America. Thirteen species of true vireo originate farther north, in the United States, Bermuda, and Canada, of which all except Hutton's vireo are migratory. Family members rarely manage long distances other than migration (Salaman & Barlow 2003). They inhabit a forest environment, with a variety of species, preferring forest canopies, underbrush or mangrove swamps (Forshaw & Parkes 1991).
Behavior
Sedentary species occur in pairs or family groups that maintain territories throughout the year (except for Hutton's vireo, which joins mixed feeding flocks). Most migrants protect winter territories from conspecifics. Exceptions are the complex including the red-eyed vireo, the yellow-green vireo, the black-whiskered vireo, and the Yucatan vireo, which winter in small wandering aggregations (Salaman & Barlow 2003).
Vote
Males of most species are regular singers. The songs are usually quite simple, monotonous in some varieties of the Caribbean coast and islands, and most elaborate and pleasing to human ears in the Chocó and peppershrikes vireo (Salaman & Barlow 2003).
Reproduction
Nests of many tropical species are unknown. Of those that are known, everyone builds a cup-shaped nest that hangs from the branches. The female does most of the incubation recorded by the male apart from the red-eyed vireo complex (Salaman & Barlow 2003).
Feeding
All family members eat some fruits, but mainly insects and other arthropods. They take prey from leaves and branches, true vireos also flycatch and gray vireo take 5 percent of their prey from the ground (Salaman & Barlow 2003).
Taxonomy
Four genera of these birds make up the family Vireonidae and are believed to be related to raven-like birds in the Corvidae family and shrikes in the Laniidae family. Recent biochemical studies have identified two kinds of talker (Pteruthius and Erpornis) who may be members of the Old World of this family (Reddy & Cracraft 2007). Observers commented on vireo-like behavior of shrike talkers Pteruthius, but apparently no one biogeographically suspected the unlikely possibility of a vireo's relatives in Asia.
The family can be comfortable, although perhaps imprecisely categorized by genus as true vireos, greenlets, shrike vireos, and peppershrikes. Preliminary genetic studies by Johnson et al. Have shown large interspecies genetic distances between clades in Vireo and Hylophilus of a similar magnitude to the differences between Cyclarhis and Vireolanius... In addition, some vireo and green-light species may be closer to peppershrikes than to their respective congeners. A more in-depth study may show this family to be significantly undersplit at both the universal and species levels.
