Eastern Warbling-Vireo (Vireo gilvus) on the wintering grounds in the highlands of Guatemala. Finally, the AOS accepted the Eastern and Western Warbling-Vireos (V. swainsoni) as distinct species (AOU 2025). Spencer F. Baird noticed differences between both taxa already in the 19th century (Baird 1858). Eastern and Western Warbling-Vireos are distinguishable in the field based on morphology and song; most field guides to North American birds draw attention to both, listed as eastern and western types of Warbling Vireo. In Guatemala, the Eastern Warbling-Vireo is a common wintering bird in the Pacific slope highlands. Archive of photographs of the month
Reference
AOS (2025) Sixty-sixth supplement to the American Ornithological Society’s Check-list of North American Birds. Ornithology 142: 1–19.
Baird, S.F. (1858) Birds. Reports of Explorations and Surveys to Ascertain the Most Practicable and Economical Route for a Railroad from the Mississippi River to the Pacific Ocean. Vol. 9. House of Representatives, Washington D.C.
