gulsidevireo Vireo flavoviridis

Fairly large vireo with a big bill and a pale eyebrow. Essentially the southern counterpart of Red-eyed Vireo. Breeds in tropical woodland and forest of Mexico and Central America, migrating south in September to South America (especially the western Amazon basin) and returning north again in March. Told from Red-eyed Vireo by its less contrasting head pattern, yellow sides and flanks, and brighter greenish upperparts. Monotonous song sounds like a House Sparrow that’s taken singing lessons.