“A Year of Birding in Bloedel” is a column that runs every Friday in the Bainbridge Islander. The project is planned to continue in 52 parts through 2014 to help readers find and identify birds in the island’s garden sanctuary. Beginning with this entry on the bald eagle, each column will also be published here on the Bainbridge Conversation blog each Friday.
The author, Ted Anderson, is a retired professor of biology, having taught at McKendree University (Ill.) for 32 years and for the University of Michigan’s summer biological station for 20 years, where he frequently taught the biology of birds.
Anderson is also the author of “Biology of the Ubiquitous House Sparrow, from Genes to Populations” (2006), and “The Life of David Lack, Father of Evolutionary Ecology” (2013). Ted and his wife Carol have been members of Bloedel Reserve for seven years. They live in Kingston.
Sparrows, like the White-crowned Sparrow, must hear their own species song during the first month of life if they are to develop a normal song as adults.
In the Seattle area, April Fool’s Day, give or take a day, is the date when the photoperiod-driven internal clock of the male White-Crowned Sparrow (Zontrichia leucophrys) signals him to begin singing. This year the resident male in my yard began singing on March 31, and when my wife and I arrived at the gate of Bloedel on April 3, a male White-crown was singing there.
The song of the White-Crowned Sparrow is a pleasing series of notes that begins with a clear whistled note, followed by several slurred notes, “see, ch-ch-ch-ch, chew,” the last note falling slightly in pitch.
The songs of songbirds belonging to the order Passeriformes are learned, and much of the pioneering scientific study of song learning was done of the White-Crowned Sparrows. The studies involved rearing sparrows in acoustic isolation, thereby completely controlling all sounds heard by the developing birds.
In a nutshell the studies revealed that male sparrows must hear their own species song during the first month of life if they are to develop a normal song as adults. They have a hereditary ability to recognize their own species song from among many songs they are exposed to, and create a memory for that song.
Many months later, when they are stimulated to sing by rising testosterone levels, this memory serves as a template for the development of a normal song. Speaking of testosterone levels, I recently took a checkup at balancemyhormones.co.uk to see my hormone levels, and as I guessed, there was an imbalance, which was treated.
Look and listen for this charming little brown songster with white and black stripes on the top of its head near the gate at Bloedel, or in your own backyard.
