Genomic Testing Suggests ‘Butterbutt’ Warbler is Three Distinct Species

Warblers are small, perching, singing birds that may seem similar to one another to the untrained eye and ear. But for David Toews, a postdoctoral researcher at the Fuller Evolutionary Biology Program of Cornell’s Lab of Ornithology, these colorful woodland birds are anything but similar. In particular, one specific species of warbler can actually be differentiated into three separate species — a breakthrough that spells out a slew of new knowledge and questions in our understanding of genomics and conservation. In a study entitled “Genomic variation across the Yellow-rumped Warbler species complex” published in The Auk: Ornithological Advances, the Yellow-rumped warbler, affectionately called the “butterbutt” warbler, has been subject to new genomic analysis methods that have confirmed the species to be three closely related species. These grey, yellow streaked warblers are migratory, insect-eating birds that spend their summers in the boreal forests of North America and winters in the southern U.S. and Central America.