Correction: October 23, 2026: In our earlier version, Momotus castaneiceps (Guatemalan Motmot) was incorrectly listed as Guatemala’s first endemic species. Podilymbus gigas (Atitlán Grebe) is an extinct, flightless water bird …
Since the late 1980s, we’ve known of an abrupt transition in Marsh Wren singing styles across the Great Plains of the United States. To the west of the transition zone, songs are harsh, grating, and highly variable, with each male having a large repertoire of up to 150 different songs. To the east, songs are semi-musical and far more homogeneous, and males learn only about 50 different songs.