Black-throated blue warbler
Chapter 3: Why and How Birds Sing
Subchapter: Why sing?
From page 28 in the book.
Photo by John Van de Graaff
♫85. Just six songs from the thousands given during one day by an unpaired male: Zur zur z-z-zreeee he sings, repeatedly, or I'm so la-la-zeeeeeee, the last note extended and rising. May 18, 2012. Cave Hill Conservation Area, Leverett, Massachusetts. (0:50)