Heeding the Call: Birding by Sound

A gray jay perches on a spruce tree.
A gray jay perches on a spruce bough at Lake Clark National Park, Alaska

NPS / K. Miller

“… four calling birds, three French hens, two turtle doves, and a partridge in a pear tree.”

Birds of many feathers are named in the popular, 18th century counting song, “The Twelve Days of Christmas.” This winter season brings another mirth-filled reason to count birds.

The 2018 National Audubon Society 118th Christmas Bird Count is underway December 14, 2017 through January 5, 2018, and national parks across the country are joining in the Western Hemisphere survey. Begun in 1900, the annual census gives Audubon, the National Park Service, and conservation-based organizations important data about the status of bird populations and ecosystems. The event also makes for a great day outdoors, and birders and non-birders alike are flocking to parks and other designated locations to participate.

Whether you are hoping to glimpse a specific bird or aid a worthwhile cause, the NPS Natural Sounds and Night Skies Division (NSNSD) encourages you to take to the field and make your observations count. In preparing, consider that the sounds of birds often aid in sightings. Focus your ears as well as eyes. In the darkness of dawn, it may be difficult to spot an owl, but hearing its hoot will give clues about its location and identity.

"Birds like the canyon wren with its small stature and rusty brown body can blend into the landscape but their call is easily heard over great distances echoing off canyon walls at Lake Mead,” said Ashley Pipkin, an NPS acoustic biologist at Lake Mead National Recreation Area. "Listening can be an easy way to check many birds off your Christmas Bird Count List!"

Birds and Habitat

Bird calls and songs are among the diverse natural sounds that contribute to the richness of an outdoor soundscape. These sounds, like their makers, are vitally linked to the ecosystems they inhabit. Take the hummingbird, for example. With tell-tale whirring of wings and high chirps, the presence of hummingbirds indicates nearby flowers. Many plant species rely on hummingbirds for pollination and have evolved traits to attract them, such as sucrose-rich nectar and brightly colored flowers. To see flourishing blooms of columbines, lupines, honeysuckle and hollyhocks is to be in hummingbird habitat. From the sweet quaver of the Yellow-rumped Warbler found in North American woods and shrub terrain, to the ratchet honks of Sandhill Cranes heard at long ranges in the freshwater wetlands of the Mid-Southwest, to the tap-tap-tap of a woodpecker in wooded areas and forests, bird sounds reveal clues about their environment.

Declining bird species are often signs of degraded habitat, and vice versa. NPS scientists record and analyze sounds in parks to identify sound sources and understand what they reveal about the condition of park environments. Technicians study these sounds using spectrograms — images that display the sounds according to brightness and color, frequency, and time of occurrence (see graphic below). The frequency for bird songs is higher than that of a jet, thunder, or vehicle, and will appear in a different frequency range on a spectrogram. In this way, they can be distinguished from other sounds. Specific species can be identified in some cases. Scientists also conduct on-site listening while monitoring in the field. Like birding, this involves quietly listening to and noting sounds heard in the environment.

The bird sounds you hear will strengthen conservation knowledge.

Four spectrograms show frequency range of bird song, a jet, thunder, and a vehicle
Different sounds occur in different frequency ranges. For example, bird song (a) is much higher in frequency than a jet (b), thunder (c), or a vehicle (d). In these spectrograms, brighter yellow indicates louder sounds.


Birding by Ear: Field Preparation

  1. Find your circle

Plan your count with these Christmas Bird Count Compiler Resources from the National Audubon Society. Count organizers will provide details that you’ll need for the day. The birding knowledge of your team leader and fellow participants will grow what you know.

  1. Know your birds

Familiarize yourself with birds and their calls in your area or active count circle. Each circle has a species checklist to help you prepare. Be sure to also check the Audubon bird gallery.

  1. Songs vs. calls

Cornell Laboratory of Ornithology, an Audubon Christmas Bird Count partner and world leader on all things birds, is another resource for learning birds. Look through their comprehensive bird guide for photos, sound recordings, and information about behavior and habitat. The audio clips will help you distinguish between bird calls — typically short and simple — and bird songs —longer and patterned. Learning something of both, even for a handful of species, will give you twice the edge toward identification.

  1. Cool birding apps

Larkwire is an engaging birding app that gives educational information for identifying birdsongs.

  1. Sound galleries

Check out these two NPS sound galleries, which feature a variety of sounds heard in parks, including a dawn chorus of birds recorded near Mammoth Hot Springs in Yellowstone National Park: NPS Sound Gallery and Yellowstone Audio Postcards.

  1. Eyes and ears

Be alert. Even the rustle of leaves and twigs may provide clues to a bird’s whereabouts. Tune all your senses to the scene. Enjoy the experience!

Article by Julie West, communications specialist with the Natural Sounds and Night Skies Division.

Last updated: September 12, 2018