| 摘要: |
| 于1996年1月，在中国科学院水生生物研究所白暨豚馆人工饲养池和湖北省石首市天鹅洲长江故道，使用频响范围分别为0－100kHz和0－16kHz的磁带记录系统，记录了一头成年雄性和一头成年雌性白暨豚的哨叫声。采用计算机信号分析系统详细分析了哨叫声的结构和声谱图，并与其它鲸类哨叫声进行比较。结果表明，白暨豚哨叫声的最大和最小频率平均值分别为5841Hz和4975Hz，频率变化幅度一般小于1000Hz。哨叫声平均持续时间为907ms。频率随时间变化不连续，且较平缓，起伏很少，有部分重叠现象。白暨豚哨叫声的结构与另一种淡水豚—亚河豚相近，但相对于一些海洋性种类（如宽吻海豚）则呈现较大的差异，表现出对环境的高度适应性。 |
| 关键词: 白暨豚 哨叫声 声谱图 |
| DOI： |
| 分类号: |
| 基金项目:中国科学院“九五”重大项目，K2951-Al-105号;国家自然科学基金资助项目，39670105号;中日科技合作资助项目“白暨豚、江豚声行为研究”。 |
附件 |
|
| STUDY ON WHISTLING OF THE CHINESE RIVER DOLPHIN (LIPOTES VEXILLIFER) |
|
WANG Ding,WANG Ke-xiong,Tomonari Akamatsu,Kaoru Fujita
|
|
1.Instliute of Hydrobiology, The Chinese Academy of Sciences, Wuhan, 430072;2.National Research Institute of Fisheries Engineering, Ebidai, Hasaki, Kashima, Ibaraki 314-0421, Japan
|
| Abstract: |
| Whistle from an adult male baiji (Lipotes vexillifer) in pool of the Institute of Hydrobiology of the Chinese Academy of Sciences in Wuhan and another adult female baiji in Tian-e-zhou Oxbow of Shishou City of Hubei Province were recorded from January 19–26 and 28–31 1996, respectively. Frequency response ranges of the recording system were 0–100kHz and 0–16kHz, respectively. Among 46 recorded whistling events, 9 were from the male baiji in the pool and 37 were from the female baiji in the oxbow. The recorded whistles were processed using a computer-based signal processing system called “signal”. The purpose of the research was to confirm if this species occupy whistles and to understand its whistle structure characteristics, compare them with those of other cetacean species, and furthermore understand their adaptation to the environmental conditions.
The results show that mean values of the maximum whistling frequency were around 5841Hz (±850, n=46), with the values for the minimum frequency of 4975Hz (±692i>n=46) and the frequency variation in one whistling event of usually less than 1000Hz. Mean duration of the whistles was 907ms (Hz (±384>n=46). The contours of the sonograms were flat and simple, with some breaks and overlaps. The frequency variation have relatively low intra-species variability, and duration and number of inflection points have a much higher intra-species variability. The sonograms of the whistles of baiji were similar to those from another platanistoid “river” dolphin species—Amazon River Dolphin or boto (Inia geoffrensis), but very much different from those of “oceanic” dolphin species, such as bottlenose dolphin (Tursiops truncatus), which shows its highly developed adaptation to environmental conditions. Since the Yangtze River carries much suspended materials, the baiji might be forced to emit whistles in a low and narrow frequency range to make the signals have a better reflective ability to transmit a longer distance. The frequency of the whistles of the baiji was higher than that of the Amazon River Dolphin; this observation is consistent with the result obtained from the research on other cetaceans that under similar environmental conditions, the longer the body length, the lower the whistle frequency, and vice versa. Overlaps of the contours of the whistles show that different parts of the whistles might result from different independent vibrating sources, which might be related to the three pairs of air sacs inside the nose channel of the baiji. Relatively low intra-species variability of frequency variables might be the result of adaptation to the environmental conditions, and high intra-species variability of duration and number of inflection point might show that the animals adjust these parts of the whistles to carry different communication information. |
| Key words: Lipotes vexillifer, Whistle, Sonogram |
