Program Information — Series 3 & 4
Click on a program in the right-hand column to see a description and program notes.

Bird Hearing

Like us, birds tend to hear best in the range of the sounds they produce. That makes sense, of course, because the communication between birds of the same species is crucial to their social organization, breeding, and daily lives.

Most songbirds sing in a range that coincides roughly with the top two octaves of the piano. Their hearing extends far below and above that range, but that's the range where they hear most acutely. (Fortunately for us, our hearing is good in most songbirds' singing range, too.)

Some migratory birds listen for the sounds of crashing waves or roiling rivers to help orient them when they are flying on cloudy nights when the moon and stars are no help in navigation. Those sounds are as much as 11 octaves below middle C and carry for miles and miles.

Bird ears look much simpler than ours. They don't have the obvious external flaps for collecting sound, their ear passages are much shorter, and the have only one bone in their middle ear instead of our three. But the tiny sound-sensing hairs and related cells in their inner ears form much more complex patterns than those in our ears. That may explain in part why they can discriminate sounds up to 20 times shorter in duration than we can.

Predatory birds tend to be able to hear very acutely across a large range of frequencies, probably because the cues they rely on to sense their prey can be anything from softly rustling vegetation to a high-pitched peep of a song or call. And nocturnal predators like owls are good at picking out very soft sounds.

Smaller birds tend to be very sensitive to the sounds their predators make, too. Acute hearing in those ranges can make the difference between life and death. And some small birds have learned to make very low-pitched alarm sounds, below the hearing ability of their predators

Chris Tenney recorded the hermit thrush in the Sierra Nevadas. He recorded the Swainson's thrush and dawn chorus along the Carmel River. The hoot of the great horned owl can be found on the CD collection Bird Songs of California from the Cornell Lab of Ornithology.

Series 3
Egg Calls
Chick ID Calls
Chicken Calls
Vocal Tract
Syrinx Styles
Airway Model
Airway Overtones
Coiled Trachea
Beak & Airway
Vowels & Airway
Tuvan Throat Singing

Series 4
Size & Sound
Forest Soundscape
Grassland Soundscape
Bird Hearing
Local Dialects
Regional Dialects
Drumming - Woodpeckers Etc.
Bird Tongues
Bird Brains & Singing
Song Duels?
Dawn Chorus
Finale: Song Sparrow