Bird Sounds Tutorial
《身而為鳥》(What it’s like to be a bird) 大衛.希伯利(David Allen Sibley)著大家出版
How do the birds chirp?
Birds make their sounds through the syrinx. Unlike the human larynx, the syrinx is deep in the respiratory tract where the bronchi meet the trachea on either side. The syrinx has two small muscles that control the two air flows independently, creating a wide variety of sounds.
Why do the birds sing?
When we listen to the sounds of nature in the wild, we always treat everything as if it were some kind of music. But bird singing is definitely more than just a show of talent. Ornithologists believe that birds sing for a specific purpose. Like humans, animals communicate through sound for courtship, vigilance, protection of territory, and begging for food. Usually, the call of birds is predominantly male, but some females will also chirp, even if they don’t sound quite the same. Some birds even have a male singing with a female, such as the Taiwan scimitar babbler, or the Steere’sliocichla. However, biologists have also found that there are some wonderfully specific states of bird sounds. For example, when raptors or natural enemies are nearby, some small birds will collectively make a medium disturbing sound, both as a warning to other small birds and as a noise to drive them away. In addition, some birds with large eyes are sensitive to light, such as the Taiwan whistling thrush, which usually rises early to chirp and continues to do so in the evening when all other wild birds have rested.
Are birds singing loudly enough to hurt their ears?
Think about it, some birds may be small but they sing loudly, so won’t that hurt their hearing? Ornithologists have found that when a bird sings, the external ear canal closes to block the sound from reaching it, but the air pressure in the chamber increases, helping to reduce vibrations. In addition, birds’ ears are covered with feathers, and those feathers, which coat the ear holes, allow birds to hear external sounds, but they also serve to dampen the noise and allow the air to flow smoothly and quietly, avoiding damage to hearing.
Source: What It’s Like to be a Birdby David Allen Sibley (translated into Chinese身而為鳥by Common Master Press)
The Beckoning Silence(搶救寂靜in Chinese) by Fan Chin-hui