Chinese alligators (photo by Prof. Kexiong WANG) 

IHB Dr. Xianyan WANG from the Research Group of Conservation Biology of Aquatic Animals published the paper entitled “Why do Chinese alligators (alligator sinensis) form bellowing choruses: a playback approach” on Journal of the Acoustical Society of America. National Geographic interviewed Dr. Wang and reported Dr. Wang’s research recently. 

Under the instruction of IHB Prof. Ding WANG, Dr. Wang and his research team have conducted systematic research on the acoustic signals and acoustic communication system of Chinese alligator, the endangered living species native only to China in the Reproduction Research Center of Chinese Alligator located in Anhui province for many years.  

Based upon field observation and playback experiments, IHB researchers found that in order to adapt to the habitat where is characteristic by luxuriant vegetation, the dominant frequency of acoustic signals emitted by Chinese alligator is very low (lower than 500 Hz). Low frequency signal is convenient for sound transmission in the circumstances covered by luxuriant vegetation. The playback experiments revealed that both male and female alligators responded equally to bellowing stimuli from the same and opposite sexes and that none of the tested alligators approached the loudspeaker in spite of playback of male or female stimuli. These suggest that Chinese alligators may not bellow to compete for or attract mates during the choruses like anurans or other animals as reported previously in some articles. Instead, they might synchronize bellows to enhance group detectability for assembling dispersed inhabited individuals into certain waters for subsequent copulations. Because Chinese alligator has no relatives in sympatry, there is no possibility of occurring species misidentification and heterospecific mating. The long-term evolution that Chinese alligator has experienced makes it require of a very vague structure of acoustic signal.  

The research of Dr. Wang and his research team has been published on Journal of the Acoustical Society of America and Ethology.  

Related link: 

　http://news.nationalgeographic.com/news/2009/10/091020-alligators-sing-singles-clubs.html