鳥音大補帖

Bird Sounds Tutorial

鳥兒是如何鳴唱的?

鳥類以「鳴管」發聲，鳴管和人類的喉頭不同，是位於呼吸道深處，就在兩側支氣管與氣管交會之處。鳴管有兩組小肌肉可以獨立控制兩組氣流，創造出千變萬化的歌聲。

鳥兒鳴唱的原因?

我們在野外聆聽大自然聲音時，總是把一切都當作某種音樂來聆聽。但是鳥類鳴唱絕對不光是展現歌藝，鳥類學家認為鳥類鳴唱有特定的目的，動物跟人一樣，透過聲音進行交流與溝通，比如求偶、警戒、鞏固地盤、乞食….通常許多鳥類主要都是公鳥的叫聲為主，但是有些母鳥也會鳴叫，甚至聲音不太一樣，甚至有些鳥類也會有一公一母相互合唱，比如小彎嘴畫眉、或是藪鳥。但是生物學家也發現鳥類聲音有一些奇妙的特定狀態，比如說，當附近有猛禽或是天敵出現時，有些小型鳥類會集體發出中滋擾的聲音，一方面是對其他小型鳥類示警，一方面也希望以噪音來驅趕敵人。另外有些眼睛很大的鳥類，對於光線很敏感，比如紫嘯鶇通常會很早就起床鳴叫，而且到了傍晚當其他野鳥都已經休息時，牠還是會繼續鳴唱。

鳥類鳴唱的聲音宏亮，是否會傷害自己的耳朵?

想想看，有些鳥類體型雖小，但是牠唱聲音很宏亮，難道不會對自己的聽覺造成傷害嗎?鳥類學家發現，鳥鳴唱時，外耳道會關閉以阻擋聲音傳入，但室內兒的氣壓會增加，有助於減少震動。另外鳥的耳朵都覆蓋羽毛，那些專門覆蓋耳洞的羽毛，雖然讓鳥類可以聽見外在聲響，但是也可以降噪功能，同時也可以讓空氣平滑安靜地流過，避免聽力受損

參考書目-

《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

搶救寂靜范欽慧著

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