Released by the Great Florida Birding & Wildlife Trail   …

The beautiful whistling song of the Eastern Meadowlark is a common sound in fields and pastures across the eastern United States. Photo by Andy Wraithmell, FWC.

Science Spotlight: Bird Song

Songs and calls of birds—the rattling cry of a Sandhill Crane, the seemingly endless repertoire of a Northern Mockingbird, the peaceful, lilting song of a Chuck-will’s-widow—are integral to the rich tapestry of nature’s sounds. This month we explore how and why birds sing.

Birders often distinguish between two types of sounds birds make. The first group, calls, are usually short, simple sounds birds can use to communicate a warning or let other birds know where they are. Where birds show their real virtuosity, however, is in songs—complex vocalizations that males typically use to attract mates or defend territories in the breeding season. Usually when you hear a bird singing it is a male – however, the females of some species like Northern Cardinals and Red-winged Blackbirds are also beautiful songsters. Song repertoire can vary greatly from species to species. Some species have one or two songs, while others (like Northern Mockingbirds or Brown Thrashers) can have a repertoire in the hundreds. The more variety for these species, the better—potential mates and rivals can get tired of hearing the same song all breeding season in the same way that humans get tired of the same song played over and over on the radio!

One of the secrets to bird song is a special organ called the syrinx that sits at the base of a bird’s trachea, or windpipe. This is the bird’s voice box and, like the human larynx, it produces sound when air from the lungs is passed over tightened membranes. The base of the syrinx is bifurcated, or split, and birds can control the two sides of the organ independently–almost as if they had two voices! Fine control over the two sides enables them to execute some truly incredible performances. Some birds, like the canary, rapidly alternate between the two sides to produce an incredibly fast trill. Others, like the Wood Thrush, can sing different notes—in differing patterns—at the same time!

Birds are born with the instruments they need to sing beautifully—but what about their repertoire? Do they break out of the egg with the knowledge of their species’ songs, or do they learn from parents? Turns out the answer is a little bit of both. By studying birds raised in acoustic isolation, scientists have learned that certain birds including doves, cowbirds, and some flycatchers know their songs innately. In the large group of birds known as the oscine songbirds, however, there is at least some learned component of song. While some species can learn songs throughout their lives, it is much more common for birds to learn when they are young. Just like it is much easier for people to learn a new language as children rather than adults, birds have a critical window of time when they practice and perfect their songs.

Birdsong is fascinating to learn about, and can also be a practical tool for birders and researchers. Identifying birds by ear can be daunting at first, but as with any new skill, patience and persistence are key. Start by taking an inventory of what you do know, and you may be surprised! Even a backyard birder has probably learned the “chickadee-dee-dee” alarm call for which the common feeder bird is named, the harsh cry of a Blue Jay, and the plaintive coo of a Mourning Dove. Mnemonic devices can also help in learning bird calls–it’s easy to remember the “who cooks for you, who cooks for you-all” of a Barred Owl or the “teakettle, teakettle, teakettle” of a Carolina Wren. There are many apps, recordings, and online resources that can help in your quest to master birding by ear, but the best way to learn, as always, is to get outside and practice!