Trills and whinnies, grunts and warbles, squawks and whistles — birds are capable of an exceptional variety of noises. Whether defending territory, revving...
Trills and whinnies, grunts and warbles, squawks and whistles — birds are capable of an exceptional variety of noises. Whether defending territory, revving up the opposite sex or yelling “HAWK!” to their neighbors, they depend on sound to survive.
This time of year birds begin to sing madly in response to the clanging of their metabolic alarm clocks: Find mate! Nest! Procreate! And birders are listening, tuning up rusty, winter-logged eardrums to play their own version of “Name That Tune.”
Birders rely on their ears more than their eyes to narrow their focus in the field and tell them what’s out there, according to Bob Sundstrom, birding tour leader and teacher of Seattle Audubon Society’s class on “birding by ear.”
“If you’re doing anything beyond very elementary birding, sounds are very important,” said Sundstrom. “Learning different types and qualities of bird song help you begin to appreciate what’s around you in a new way.”
Like listening to a symphony and identifying the individual instruments that make up the whole, birding by ear brings new insight into forest orchestrations.
Sundstrom uses a variety of methods to help students memorize bird sounds. Some people work best with sound-alike phrases such as “potato chip, potato chip” for the American goldfinch or the “quick three beers!” of the olive-sided flycatcher. The more literal-minded might be drawn to using dots, squiggles and dashes in a kind of shorthand song translation. Some count the elements in a song, such as noting that the Nashville warbler’s two-syllable phrase is followed by a trill. Still others distinguish bird songs by their musical qualities, such as the varying warbles of three local finches. Most people use a combination of these approaches.
Audubon takes to the air
Now you can learn bird songs on your daily commute. To foster bird education and appreciation, Seattle Audubon Society has partnered with KPLU Radio to produce a new radio segment called “BirdNote.” A different bird is featured each weekday from 8:58 to 9 a.m. on KPLU-FM 88.5. The segments are available to listen to online at www.birdnote.org. “Birds are kind of invisible until people have a sense of what they are hearing,” says Christina Peterson, executive producer of BirdNote. “I want people to walk outside after hearing a segment and say, ‘Oh, that’s what that is!’ When you know something about a species, you have a window on the natural world and the environment becomes richer.”
A swarm of songs“It’s a life-long process and I’m still learning,” said Sundstrom. “The easiest way to turn yourself off completely is to take one of these dictionary-type CD collections and listen to 30 warblers in a row. With 20 seconds of each, you’d decide there was really no hope.”
Instead, Sundstrom recommends focusing on the songs of a few resident species (see accompanying “Tips to get you started”), and trying to learn only three or four at a time. Begin your listening practice before April, when arriving migrant species muddy the sound palette. He said it helps to make a recording of songs you’re likely to hear locally and the ones you most want to learn.
One time of day when it’s probably wise for beginners not to practice honing their skills is very early in the morning, when it’s difficult to identify individual songs. Known as the dawn chorus, some would call this a euphemistic term for the daily bird cacophony that verifies the arrival of spring.
George Bentley, a University of Washington professor of zoology who teaches the upcoming Seattle Audubon class “How Do Birds Sing and Why?”, summarizes theories on what triggers this desperate-sounding opus:
• The dawn chorus may be an indicator of energetic fitness. Many small songbirds are on an energetic knife-edge through the night — especially during the colder months. Song at dawn might be a way in which males can show off to females that they have energy reserves despite the long fast. This might indicate provider status (i.e., they can provide well for themselves, hence they have good genes, etc.).
• Another theory has to do with sound transmission. Wind is often minimal at dawn, and by some estimates song at dawn is broadcast 20 times more effectively than at any other time of day.
Seattle Audubon Society: “How Do Birds Sing and Why?” taught by George Bentley, Ph.D., Department of Zoology, University of Washington. March 23 and 25. $30 for Audubon members, $45 nonmembers. To register: 206-523-4483 or www.seattleaudubon.org
Vashon Island Audubon Society: “Birding by Ear,” taught by Steve Caldwell. Starts March 22. To register, call the instructor at 206-463-5778.
Seattle Audubon: “Birding by Ear,” taught by Bob Sundstrom. Starts May 4. To register: 206-523-4483 or www.seattleaudubon.org
• A third idea is that since it is still dark and foraging is not possible, this is a good time to sing, establish territory boundaries and attract/defend mates.
• And finally, females are often most fertile at dawn, so singing to warn off other males is a good way to guard against extra-pair fertilizations.
How birds produce sound is just as interesting. They don’t have a voice box or larynx atop the trachea, as humans do. Instead they have a syrinx, which wraps around the two bronchi and the trachea. “Because each bronchus can produce a sound of its own, the bird can produce two sounds at once,” said Bentley. “Check out starlings on telephone wires — they will whistle and click all at once, as well as flap their wings!
“Birds are very complex. Because they can learn songs so well and their brain is so dynamic, the term birdbrain is a misnomer,” said Bentley, who studies the neurobiology of birdsong.
Easy listeningThe more you learn about why birds sing, the clearer it becomes that birds are definitely not just making noise. Male birdsong is even responsible for hormonal surges in the female.
“How the female’s brain takes sound cues and integrates them into a hormonal cue, we really don’t understand,” Bentley said. “We have also learned that there are certain syllables the females find super sexy. They tend to go for the most complex syllables, so songs with lots of harmonics and rapid-frequency modulation are the ones they like best.”
Beyond the hows and whys, most birders say they just like listening to birds. At the risk of sounding corny, Sundstrom says their songs can be magical.
“I really enjoy bird sounds, not just the intellectual part,” he said. “It’s mainly for the enjoyment.”
Kathryn True, a freelance writer who lives on Vashon Island, is co-author of “Nature in the City: Seattle” (The Mountaineers Books, 2003).