Most birds have distinct calls that tend to stay the same. It’s how birders can recognize a species without seeing it. But new research shows these tunes can change. Over the course of two decades, ...

Koni Sundquist of Duluth called Thursday to say she had heard her first white-throated sparrow call of the season. For many, that pure, high-pitched call -- "Old Sam Peabody, Peabody, Peabody" -- is ...