Vireos, Greenlets, Shrike-babblers

Vireos are a family of small to medium-sized songbirds (Vireonidae) generally characterized by their dull, greenish plumage, found across the New World from Canada to Argentina, as well as Southeast Asia. The family comprises six genera, with a size range from the tiny Chocó vireo at 10 cm and 8 g to the larger peppershrikes at 17 cm and 40 g. These birds prefer forest environments, including canopies, undergrowth, and mangrove swamps. Most vireos from the US, Bermuda, and Canada are migratory, while others in Middle and South America are resident, often living in pairs or family groups that defend territories year-round. Vireo males are known for their singing, with variations in song complexity. Their breeding habits involve cup-shaped nests hanging from branches, with the female primarily responsible for incubation. Vireos mainly feed on insects and other arthropods, gleaning them from foliage or occasionally catching them in flight. The family is related to crows (Corvidae) and shrikes (Laniidae), and recent studies suggest unexpected relations to Asian genera Pteruthius and Erpornis, known as shrike-babblers. This diverse group, which includes the true vireos, greenlets, shrike-vireos, and peppershrikes, may be underrepresented at the generic and species levels, hinting at a more intricate taxonomic structure. The genera Vireo, Hylophilus, Tunchiornis, Pachysylvia, Cyclarhis, Vireolanius, and the Asian Pteruthius and Erpornis host many species, including the distinctive red-eyed vireo complex and various species unique to islands and specific habitats.