五种蝙蝠形态与回声定位叫声的性别差异

Sexual differences in morphology and echolocation calls in five Chinese bat species

为研究角菊头蝠 (Rhinolophuscornutus)、三叶蹄蝠 (Aselliscuswheeleri)、大蹄蝠 (Hipposiderosarmiger)、大鼠耳蝠 (Myotismyotis)和大足鼠耳蝠 (M .ricketti)的形态和回声定位叫声的性别差异性 ,明确同种蝙蝠雌雄个体对食物、栖息地等资源利用的细微差异 ,我们利用超声波探测仪、Batsound分析软件及SPSS11 0统计软件对 5种 95只蝙蝠进行了录音、声波分析和统计分析。 5种蝙蝠形态性别差异性不显著 ,角菊头蝠、三叶蹄蝠、大蹄蝠和大足鼠耳蝠叫声频率性别差异性显著 ,大鼠耳蝠叫声频率性别差异性不显著。角菊头蝠雌性叫声的基频、分音、主频率高于雄性 ,声脉冲时间、间隔时间大于雄性 ,调频 (FM)带宽小于雄性 ;三叶蹄蝠、大蹄蝠叫声的基频、主频率雄性高于雌性 ,调频带宽雌性小于雄性 ;大足鼠耳蝠叫声的主频率雄性高于雌性 。

We studied sexual differences in morphology and echolocation calls in five bat species, which included three species of CF FM bats ( Rhinolophus cornutus, Aselliscus wheeleri, Hipposideros armiger ) and two species of FM bats ( Myotis myotis and M. ricketti ). The five bat species (a total of 95 bats) were captured in June 2000 and May and June 2002 in the caves in four districts including Zhenfeng, Zhenning, Anlong and Xishui in Guizhou Province, China. Bats were captured at the entrance of caves with the mist nets at about 8 pm (the time when bats usually flied out of caves to hunt preys), and then were put into a recording room near the capture locations to allow them to fly freely. About 2 hours later, the recording was carried out by an ultrasound detector (with frequencies down to 5 kHz and up to 205 kHz, D980) which was pointed to the head of the bats when they flied to the microphone directly and echolocation calls were recorded when the bats were about 1 meter away from the microphone. The echolocation calls were stored in a memory array (12 s real time), read out at one tenth of the original speed and recorded with a digital sound recorder (TCD D8, sampling rate of 44 10 or 22 05 kHz, frequency response range: 30-20 000 Hz). Each bat was recorded for 5 to 10 times. The recorded echolocation signals were analyzed with a sound processing software, Batsound 3 10 (developed by Pettersson Elektronik AB, Sweden) on a computer. The ultrasound analysis included color sonagram (frequency time graph) with FFT of 256 Hz and the Hanning window was used. The analysis attenuation was 60 dB. The pulse duration, pulse interval (from the beginning of one pulse to the beginning of the next pulse), frequency bandwidth (FB) and dominant frequency (DF) of the echolocation calls were measured. The morphological features such as body mass, body length, forearm length, tail length, feet length (together with the claws) were measured with balance and ruler. Statistical analysis such as calculating mean value, standard error and independent samples t test were performed using statistical software SPSS 11 5 Our studies showed that these five bat species do not show sexual differences in morphology. However, significant sexual differences in the dominant frequency of echolocation calls were found in four bat species. While the dominant frequency component of echolocation calls was higher in female than in male R. cornutus , the opposite was found in A. wheeleri, H. armiger , and M. ricketti , and no significant difference in echolocation calls of female and male M. myotis was found. It was concluded that within the same bat species it was sex, not body size that determined the dominant frequency. Together with the other bat species which have been researched on their sexual difference in morphology and echolocation calls, we can infer that in Rhinolophidae, the female bats have higher dominant frequency than the male ones; in Hipposideridae, the female bats have lower dominant frequency than the male ones; in Vespertilionidae, some bat species have significant sexual difference and in these species the female bats have lower dominant frequency than the male ones, but some bat species have not significant difference.