Supplementary text and song spectrograms of putative hybrid and parental species from A wood-warbler produced through both interspecific and intergeneric hybridization

Figure S1. The songs of the putative hybrid warbler (A) and presumed parental species, obtained from the Macaulay Library ( The song notes of the hybrid are similar in quality, length, and structure as observed in chestnut-sided warblers (B). These contrast strongly with the “buzzy” songs of blue-winged and golden-winged warblers (C and D).