Keuper A, Kühne R
Fachbereich Biologie, Philipps-Universität, D-3550 Marburg, Federal Republic of Germany.
Behav Processes. 1983 May;8(2):125-45. doi: 10.1016/0376-6357(83)90002-5.
The airborne-sound and the vibratory signals produced by stridulating Tettigonia cantans males, and the transmission of these signals in the natural biotope were investigated. The song of T. cantans is composed of repeated uniform syllables with a rate of ca. 30/sec. Intensity approaches 100 dB SPL, 10 cm away from the animal. The spectrum shows three dominant frequency ranges around 8, 16 and 32 kHz. Airborne transmission of the song in such vegetation layers as are found in the biotopes of T. cantans shows an excess attenuation which increases with frequency. The relative intensities of the frequency components of the song vary as a result of the kind of vegetation, the positions of emitter and receiver, and the separation distance. These relative differences in intensity may be useful during the phonotactic approach to conspecific partners, providing a measure of the distance from the sound source. Stridulating males also produce vibratory signals in the plants they sit on. The spectrum of these signals includes frequencies up to 8 kHz, the first dominant frequency of the song: low frequency components are induced in the plants via the legs and abdomen of the animal. The vibratory signals are transmitted mainly in the form of bending waves. Near the animal, amplitude modulation corresponds to that of the song. At greater distances, reflections and frequency-dependent propagation velocities, cause distortions of this time pattern. Transmission depends greatly on the mechanical properties of the particular plant, attenuation values of 20-50 dB/m being found. Nevertheless, in most cases, vibratory signals may be perceived up to 1.5 - 2 metres away from a stridulating male.
对鸣螽雄性发出的空气传播声音和振动信号，以及这些信号在自然栖息地中的传播进行了研究。鸣螽的鸣声由重复的均匀音节组成，速率约为每秒30个。在距离动物10厘米处，强度接近100分贝声压级。频谱显示在8千赫、16千赫和32千赫左右有三个主要频率范围。在鸣螽栖息地中发现的此类植被层中，鸣声的空气传播表现出随频率增加的过量衰减。鸣声频率成分的相对强度因植被种类、发射器和接收器的位置以及分离距离而异。这些强度上的相对差异在向同种伙伴的趋声接近过程中可能是有用的，可提供与声源距离的一种度量。鸣叫的雄性还会在它们所栖息的植物上产生振动信号。这些信号的频谱包括高达8千赫的频率，即鸣声的第一个主要频率：低频成分通过动物的腿部和腹部在植物中诱发。振动信号主要以弯曲波的形式传播。在动物附近，幅度调制与鸣声的幅度调制相对应。在更大距离处，反射和频率相关的传播速度会导致这种时间模式的失真。传播很大程度上取决于特定植物的机械特性，衰减值为20 - 50分贝/米。然而，在大多数情况下，在距离鸣叫雄性1.5 - 2米远时仍可感知到振动信号。
