Vail Daily column: Bird songs bring added dimension to winter landscape
There are many beautiful aspects of winter. Some love the blanket of white strewn across the mountains. Others enjoy recreation that celebrates the unique qualities of snow. I think the part I enjoy most is the noise dampening value of snow. To be immersed in silent, white woods is a wondrous thing. As we run into March, however, that silence will be broken by an equally beautiful phenomenon: bird song. Thus far this winter we have been restricted to the guttural caw of the raven, the ratcheting of the magpie and the occasional “chick-a-dee-dee” of the chickadee. Soon the hills will be alive with song as we welcome back our songbirds.
Sweet Sounds from the Syrinx
When our songbirds (birds under the Passeriformes order) return from their winter abodes down south, they will have much to talk about. But their speech is different from ours in more ways than we realize. Our voice box (larynx) is located at the top of our trachea and houses our vocal chords. The larynx allows us to manipulate pitch and volume and, with the vibrating vocal chords, allows us to speak. Birds, on the other hand, have a specialized voice box called a syrinx. The syrinx is a two-sided organ located where the trachea splits into two bronchial tubes. Birds can actually control each side independently, meaning they can produce two different pitches at the same time! Because they can switch sides of the syrinx seamlessly, Northern Cardinals can sweep through more notes than are on a piano keyboard in just a tenth of a second! This amazing organ gives birds the abilities to sing, make calls and even imitate the sounds of other animals. Though our voice boxes are very different, we actually have a few things in common with birds.
Just as we learn behavior from our elders and tutors, many birds also must learn their songs by listening to adults and neighbors. We know practice makes perfect and the same goes for young birds. Certain species can learn up to 100 different songs, so they need to practice often. Dialects can give us hints as to where people are from. In much the same way, birds of the same species who have been separated by mountains or bodies of water develop variations in their song, giving us differing dialects from the same species.
Defense and Mating
But why do birds bother singing at all? There are two main reasons for birds to vocalize: To proclaim and defend territories and to attract mates. When we hear the melodious songs of birds, it is most often the male doing the calling. Females make some of the noise, but the males make longer, more complex vocalizations to establish their realms and attract the girls.
What songs will we in the valley begin to hear in months to come? This month should yield a few finches including the pine siskin and the Cassin’s finch. Pine siskins produce high-pitched trills and slurs while Cassin’s finches have a fast, warbling song with short syllables. Those on the mountain should keep an eye out for streaks of blue as the mountain bluebird returns to us in March. These vibrant thrushes can also be identified by their descending “chirp, chir-ir-irp” sound. March will also bring the Say’s phoebe, who enjoys our down-valley scrublands and makes a low, whistled “pit-tsee-eur.” Later, into April, be on the lookout for the bullet–fast swallows and the melodious house wren, who will be joining their friends in the spring nesting frenzy.
The sounds of birds add a new dimension to a landscape that is rich in so many ways. Next time you are enjoying snow recreation or out for a stroll, keep your ears open for new bird voices. Don’t forget your binoculars!
Kyle Groen is a naturalist at Walking Mountains Science Center in Avon who never leaves home without his bird guide and a good pair of binoculars.