Song Sparrow recorded in Berkeley County WV. 6 June 2009 © Wil Hershberger. A binaural recording.
One of my favorite songs of spring is that of the Song Sparrow. The stereo recording above features a wonderfully talented virtuoso. His voice is so clear and enchanting I could listen to him all day. I recorded him near my home in West Virginia. Listen for the songs of Yellow Warbler and Common Yellowthroat in the background.
At first you may think that this male has only one song type at his disposal, because he repeats exactly the same pattern over and over. But if you listen for awhile, you will soon discover that he periodically switches to a new song type. In fact, most Song Sparrow males have about ten different song types in their repertoires. At dawn, they may switch song patterns every minute or so. Later in the day, they may sing one pattern for a number of minutes before finally changing.
Below is a study of five song patterns from this one male. He sang all of these different song types in the span of one hour. Can you hear the differences?
Five different Song Sparrow song types from one individual. Recorded in the morning within a one hour time span. Berkeley County WV. 6 June 2009 © Wil Hershberger.
Males of many songbirds, including Song Sparrows, learn the basic song pattern of their species from their fathers, shortly after hatching. But when they set up territories of their own, other factors come into play.
In non-migratory populations of Song Sparrows, fledgling males leave the nesting area and search for their own territory. It isn’t easy. The resident males chase and sing at the young intruder as he tries to find a place to call home. Once he finds an empty territory, he quickly learns the songs of his new neighbors, memorizing every detail and adding some of their songs to his repertoire. These “shared songs” are perfect replicas of each other, there is very little innovation or re-mixing of song patterns. Neighboring males often match song types, or shared songs, as they sing back-and-forth during territorial encounters. Matching the exact song type with a singing neighbor is more aggressive than singing back a shared song that is not the prefect match. Song Sparrow communication is a lot more sophisticated than we might have expected.
By April of the year following his birth, the male Song Sparrow will have learned all that he will ever learn regarding songs and singing. His repertoire is set. Even though he learned songs from his father, those songs are long gone. They are not important in this new location where the young male must match the songs of his new rivals.
To learn more about songbirds and song learning be sure to read Dr. Don Kroodsma’s amazing book, “The Singing Life of Birds,” published by Houghton Mifflin Co. 2005.