ABSTRACT
The vireos include only four genera confined to the New World. Some are quite wood-warbler-like in plumage, but have an antbird-like structure with a heavy, often hooked bill for eating large insects and sometimes fruit. Several species are surprisingly similar in appearance to syntopic non-vireos, like Hylophilus ochraceiceps is to Myrmotherula menetriesii, Vireo olivaceus is to Oreothlypis peregrina, Vireo huttonii is to Regulus calendula, and Vireo flavifrons is to Setophaga pinus. Molt in vireos is similar to that of other passerines, often following a Complex Basic Strategy in nonmigrants or short-distance migrants, and a Complex Alternate Strategy in short-distance and long-distance migrants. Preformative molts in most if not all migrants are partial to incomplete, but can apparently be complete in at least some resident Neotropical species. Red-eyed Vireos have a prealternate molt, but their preformative molt may be more extensive than in migratory North American populations.
