A sparrow song remix took over North America with astonishing speed
Some North American birds are changing their tune. The traditional song of the white-throated sparrow (Zonotrichia albicollis) ends with a repeated triplet of notes. By 2000, however, some birds in western Canada were whistling a variation ending in a two-note pattern. That new song has since spread widely across North America, researchers report online July 2 in Current Biology. The findings fly in the face of previous hypotheses that birdsong dialects don’t change much within local regions. The rapid spread of the new song is akin to someone moving from Kentucky to Vancouver and everyone in Vancouver suddenly picking up a Kentucky accent, says Ken Otter, an avian behavioral ecologist at the University of Northern British Columbia in Prince George, Canada. Otter and his colleagues documented the adoption of the western song at a research station in eastern Canada. In 2005, only one male out of 76 surveyed sang the doublet-ending song. In...