About Amazilia yucatanensis (S.Cabot, 1845)
The buff-bellied hummingbird (Amazilia yucatanensis (S.Cabot, 1845)) measures 10 to 11 cm (3.9 to 4.3 in) in length and weighs 2.9 to 4.7 g (0.10 to 0.17 oz). Adult males have a rosy reddish bill with a dusky tip, while females have more dark coloration on the upper bill (maxilla). For the nominate subspecies, adult males have metallic bronze green upperparts that are duller and darker on the crown. Their uppertail coverts are a mix of bronze green and cinnamon rufous. Their tail feathers are chestnut at the base and metallic bronze at the end. Their chin, throat, and chest are bright metallic yellowish emerald green, and their vent area and undertail coverts are deep cinnamon rufous. The adult female is similar to the male, but has a less iridescent back and throat. Its central tail feathers are mostly greenish bronze, and the outer tail feathers are mostly chestnut with greenish bronze edges and tips. Subspecies A. y. chalconota has a bronze sheen on its upperparts, and its vent area and undertail coverts are light cinnamon-buff with interspersed bronze or bronze-green. A. y. cerviniventris is very similar to chalconota, but has less bronze on the upperparts. The nominate subspecies lives year-round from northern Belize and northwestern Guatemala north to Tabasco, Campeche, and Yucatán in southeastern Mexico. A. y. chalconota occurs year-round from extreme southern Texas south through Mexico to north-central Veracruz, and can also be found further north and east in the United States during winter. A. y. cerviniventris lives year-round from central Veracruz south through Puebla and Oaxaca to northern Chiapas. Across its year-round range, the buff-bellied hummingbird lives in a variety of landscapes, most of which are semi-open to open and rather dry. These habitats include scrubby woodlands, edges of denser forest, thorn forest, oak woodlands, oak "islands" in grasslands, and urban and suburban parks and gardens. No detailed information is available about its habitat preferences in the United States during winter dispersal.
