Young Bruce A, Aguiar Amie
Department of Biology, Lafayette College, Easton, PA 18042, USA.
J Exp Biol. 2002 Oct;205(Pt 19):3087-92. doi: 10.1242/jeb.205.19.3087.
In order to test the hypothesis that snakes can not only perceive airborne sounds, but also respond to them, an acoustic isolation chamber was designed and constructed to perform best within the 150-450 Hz range in which snakes perceive sound. Suspended within this acoustic chamber was a steel mesh basket designed to minimize the potential for groundborne vibrations. A synthesized tone was created out of 20 different 150 ms sounds, each separated by a 50 ms period of silence; the acoustic energy of each of the 20 sounds was concentrated between 200-400 Hz, and each sound included frequency modulation. The trial stimuli were presented to western diamondback rattlesnakes Crotalus atrox at a level 5-10 dB above their perception threshold. Four significant behavioural responses were observed upon stimulus presentation: cessation of body movements, reduction or cessation of tongue flicking, rapid jerks of the head and rattling. At least one significant behavioural response was observed in 92% of the behavioural trials. This study provides the first experimental evidence that snakes can respond behaviourally to airborne sounds.
为了验证蛇不仅能感知空气中的声音，还能对其做出反应这一假设，设计并建造了一个隔音室，使其在蛇能感知声音的150 - 450赫兹范围内表现最佳。悬挂在这个隔音室内的是一个钢丝网篮，其设计目的是尽量减少地面振动的可能性。由20种不同的150毫秒声音合成一个音调，每个声音之间由50毫秒的静音隔开；这20种声音中的每一种的声能都集中在200 - 400赫兹之间，并且每种声音都包含频率调制。试验刺激以高于西部菱斑响尾蛇（Crotalus atrox）感知阈值5 - 10分贝的水平呈现给它们。在呈现刺激时观察到四种明显的行为反应：身体动作停止、吐舌减少或停止、头部快速抽搐和发出嘎嘎声。在92%的行为试验中观察到至少一种明显的行为反应。这项研究提供了首个实验证据，证明蛇能对空气中的声音做出行为反应。
