同一噪音环境下武夷湍蛙与凹耳蛙的求偶鸣声特征比较及其适应策略

Comparison of mating calls and adaptive strategies of Amolops wuyiensis and Odorrana tormotus (Anura) in noise-controlled environments

为了解同域分布的两种无尾两栖类动物武夷湍蛙（Amolops wuyiensis）和凹耳蛙（Odorrana tormotus）在高噪音环境下的求偶呜声特征及其适应策略，该研究利用超声录音设备录制并分析了繁殖季节武夷湍蛙和凹耳蛙雄性个体在同一噪音环境下的求偶鸣声。结果显示，繁殖期武夷湍蛙在不同时段均能发出3-6个音节数不等的单一鸣声，每个音节由2—10个声脉冲组成，鸣声平均持续时间为2198．20ms，主频为2231．90Hz，信噪声强差为33．00dB，且鸣声不含超声组分，不具备超声通讯的基础。凹耳蛙在每天的18：00-21：00有集中呜叫行为，呜声平均持续时间为331．80ms，主频为6665．50Hz，信噪声强差为37．00dB，且呜声谐波包含超声组分，与前人描述一致。经进一步分析发现，武夷湍蛙和凹耳蛙的鸣声主频和声强均高于背景噪音，噪音不会对其鸣声产生掩蔽作用。通过比较分析得知，武夷湍蛙鸣声主频率〈凹耳蛙，推测其声信号传播距离相对后者更远，该蛙在噪音环境下有可能通过调整自身的发声策略（即采用多音节呜叫声、增加呜叫时长和呜叫频次等）来完成种内通讯，并通过改变呜声时长来体现雄性自身的品质，以便提高对雌性的吸引力。而相同噪音环境下的凹耳蛙则可能采用较为节约能量的方式提高声信号频率的通讯策略，完成种内竞争和交流。

In order to understand the acoustic characteristics and adaptive strategies of sympatric male Amolops wuyiensis and male Odorrana tormotus in environments controlled for high noise levels, we recorded and analyzed the advertisement calls produced by individual males during breeding season. The results show that A. wuyiensis produced a single type of call composed of variable syllables （from 3 to 6 syllables） with 2-10 pulses over different time periods. The average values of call duration, dominant frequency and signal noise ratio were 2 198.20 ms, 2 231.90 Hz and 33.00 dB respectively. There were no ultrasonic elements in A. wuyiensis calls and they did not have the basis of ultrasonic communication. The average values of call duration, dominant frequency and signal noise ratio of O. tormotus were 331.80 ms, 6665.50 Hz and 37.00 dB respectively. Call structure of O. tormotus was consistent with previous studies. The noise did not mask the calls from the male A. wuyiensis and male O. tormotus, which have higher frequencies and amplitudes. To fulfill the intra-species communication in a noise-controlled environment, the A. wuyiensis male, which has a low vocal frequency and long transmission length, varied vocal frequency, composition, and duration, the latter of which serves to attract females. By contrast, the male O. tormotus increased vocal frequency, which reduces the energy expended on intra-species communication.