Sentence:  Uniquely American, the <WSD>vireos</WSD> are a group of some 46 foliage-gleaning forest birds with uncertain family connections. <WSD>Vireo</WSD> species are about equally divided between North and South America, with one, the Black-whiskered <WSD>Vireo</WSD>, largely restricted to the West Indies. Several <WSD>vireos</WSD> make long migratory journeys; all are nocturnal migrants. 
Meaning of the word marked with <WSD> tags:  Any of a number of small insectivorous passerine birds, of the genus "Vireo", that have grey-green plumage.