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Canadian sparrows ditch their old song for catchier tune
by buteos

    For years, the small songbird’s traditional descending whistle featured a three-note ending. But researchers have tracked how a unique two-note-ending version of the male bird’s call has rapidly spread 3,000km (1,864 miles) eastwards from western Canada to central Ontario during this century.

    Many bird species are known to change their songs over time but these “cultural” evolutions usually stay within local populations, becoming a regional “dialect” rather than the new normal for a whole species. Scientists have not previously observed how a new song dialect quickly moves across a continent.

    “As far as we know, it’s unprecedented,” said Ken Otter, a biology professor at the University of Northern British Columbia. “We don’t know of any other study that has ever seen this sort of spread through cultural evolution of a song type.”