The Sounds of Silence; NOT!!

Birdsong has inspired and delighted people since time immemorial. Particularly in spring, when most beings are emerging from winter's grip, birds sing their joyous songs from dense chaparral, lush meadows, deep forests and rolling hillsides. Theories abound about why birds sing and what they are doing. Generally, it is thought to be related to breeding and rearing young. Watching a Lazuli Bunting perched atop the tallest tree throw his head back and let loose his sylvan trill, it is hard not to see it as the purest expression of joy. 

The language of birds is far more intricate than one would imagine, and researchers are discovering more complexities daily. A lot of birding is done by ear. With practice, one can pick out different species by song or call, and an experienced birder may be able to describe behavior or attitude based on the quality, pitch or rhythm of the sound. The catch is that birds hear us too, and are sensitive to any change in their environment. Very often, once we enter their habitat, birds become silent and even more secretive.

Last week Kathleen and I watched a Blue Gray Gnatcatcher sitting in a shrub, lit up by the sun and preening and singing! We were both familiar with its wheezy, whispery call, but had never heard the extended version. David Sibley, in The Sibley Guide to Bird Life & Behavior (2002, p. 455) wrote, "During the breeding season, male sylviids sing advertising songs, primarily while establishing territories and nesting." This lovely little guy finally flew up and over the ridgeline, indicating he was probably not establishing territory.  Perhaps he was heading back home to his nest and mate. While not enough data to confirm him as nesting, we'll return next week to see if we can catch him (or his mate) carrying nesting material or food.

With many of our territories accessible only by main roads, we are challenged to hear over the roar of traffic. Add to this the sounds of farm equipment and machinery, chain saws, and leaf blowers and it becomes increasingly difficult. Each time we enter a new environment to observe, we stand quietly for several minutes, listening, and waiting for wildlife to adapt to our presence and continue with their lives. Wild animals' very existence depends upon their being hyper aware of any change in their environment, so they are sensitive to all potential predators.

In an article titled "The Birding Effect" (Nature Conservancy Magazine; May/June 2013), Melissa Migrom wrote, "Research in Peru found that the human voice speaking at 50 decibels--the volume typically used inside a library--reduced bird sightings by more than 30 percent." While this surprised me, it matches my observations. Each time we pull over and get out of the car, most birds stop singing.  They disappear behind leaves and branches and we become the observed, as they peer over a leaf or around a treetrunk! Though Kathleen and I are practiced at communicating with glances, (oftentimes verbal communication is unnecessary and we find later that we were thinking the same thoughts!) we find it tricky to stay still and quiet long enough to become accepted as non threatening.

One morning, our friend Mary Rooney, Kathleen and I watched as turf wars were waged at one dead oak tree with multiple potential nest sites;  A virtual condominium!  A pair of Western bluebirds had staked a claim on a lovely nest hole, with Violet Green Swallows and Tree Swallows eyeing other potential cavities.  White breasted nuthatches, chickadees, Oak Titmice and bushtits were all in the vicinity.  Finally, an aggressive, invasive, non native starling roared into the neighborhood, stealing the prime site for himself.  In successive weeks we revisited the spot to find it devoid of any nesting birds, except the starling.  The only change in the environment was that a nearby winery building was emitting a continual loud, rumbling noise.

I am constantly aware of how much noise we humans make in almost every environment, especially around my own home where Arnold Drive is a continual roar. In the almost 40 years since I moved to Sonoma, the noise level has increased dramatically (as has the manmade light level, diminishing the brilliance of the stars), and bird habitat has diminished shockingly. Change is inevitable, and necessary. For myself, I try to be aware of how much noise I contribute to an increasingly loud environment.