As we welcome in 2008, some of us may be looking for a New Year’s Resolution. New Year’s Resolutions usually involve something that would improve your health, but why not pick something that would improve your birding skills? Perhaps a good one would be to work harder on bird sound identification. Many birders probably think of birding by ear as something you do in the spring and summer, when birds are singing. This is true enough, but birds make sounds all year round. Learning how to listen to these sounds can help you get more out of birding at any season.
One way to approach birding by ear is to relate it to the parameters you already use in visual identification. When identifying birds visually, it is always best to start with size, structure, and behavior. Applying these same parameters to bird sound identification will help you hear sounds in more detail and recall them more easily later.
SIZE
The “size” of a sound is simply its loudness. Of course, with most birds, there is considerable variation in how loud a call or song is. However, there are still useful, predictable differences. For example, the squawk of a Great Blue Heron is just about always going to be louder than the “ji-dit” of a Ruby-crowned Kinglet. On a more subtle scale, the “tchup” of a Brown Thrasher is, on average, louder than the “tchup” of a Fox Sparrow. These average differences can help you learn the typical songs and calls even though they may not always be diagnostic on their own.
STRUCTURE
The “structure” of a bird song or call covers a lot of ground. First of all there’s pitch, which is how high or low a sound is, determined by its rate of vibration. It helps to consider pitch relative to another familiar bird sound. For example, the chip of a Northern Cardinal is higher pitched than the chip of a White-throated Sparrow. It is just as valuable to listen for any change in pitch through the song or call. Like the descending quality of a Downy Woodpecker’s whinny call. These changes in pitch are what create the pattern of a song or call. For example, a Black-capped Chickadee sings a two-note “fee-bee” with the first note higher and the second note lower.
One of the most important aspects of a sound’s “structure” is quality. For example, some sounds are pure-toned and may have a whistled quality, like the “fee-bee” song of a Black-capped Chickadee. Others may have a husky or rough quality, like the “fee-bee” song of an Eastern Phoebe. Describing the quality of a sound is a decidedly subjective game, but the more that quality is compared to other familiar sounds, the easier it is to remember.
Another aspect of structure that applies more to bird songs than calls is rhythm. Rhythm is the time between phrases and songs. For species with more complicated or variable patterns to their songs, it is usually the rhythm that is more distinctive than any particular patterns. For example, a Northern Mockingbird sings a slow progression of highly varied phrases that are repeated about one to six times. On the other hand, a Brown Thrasher, which can sound similar to a Mockingbird, sings at a slow pace with evenly paired phrases and long pauses.
BEHAVIOR
Of course, a sound cannot have a behavior but a bird can. For every bird sound you hear, there is some behavioral context that can aid in identification. For starters, what habitat is the bird in? Is it calling from a dense thicket, from a hay field, from a shaded forest, from a salt marsh, from the sky? Also, the time of day that a bird calls can sometimes be a clue. Another behavioral quality that can often be helpful is calling rate. Some species tend to give their call multiple times in rapid succession while others tend to give single calls infrequently. The same is true for songs. Some species tend to sing endlessly while others sing less frequently. Such behavioral clues will never by diagnostic on their own but they will often help whittle down the choices and may help you distinguish between a mimic and the real thing.
| Figure 1 – White-throated Sparrow, December, New Jersey.
All birds make sounds. Whether its winter, spring, summer, or fall, we can practice our birding-by-ear skills every time we venture into the field. Try applying the “size, structure, and behavior” parameters to bird sounds and see if you begin to recognize more of what you hear. |
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