Recently, Dr. CUI Jianguo and his colleague in Chengdu Institute of Biology, Chinese Academy of Sciences investigated relationships between body size and call structure in the large treefrog, Rhacophorus dennysi,a beautiful green frog produces euphonious calls on trees. The authors recorded the advertisement calls of 27 male frogs and measured their body mass and snout-vent length (SVL) correspondingly.
Meanwhile, they found that the dominant and fundamental frequencies are negatively correlated with body size, while the inter-note intervals are positively correlated with body size. These results support the idea that call characters reflect information concerning body size which could facilitate decision making related to male-male competition and female selection.
Additionally, the authors also investigated the circadian pattern of calling behavior and the relationship of calling behavior with air temperature and humidity. The researchers found that call activity shows an apparently circadian rhythm in which relatively higher temperature and lower humidity may inhibit calling in the tropical species R. dennysi.
The paper entitled " Effects of Body Size and Environmental Factors on the Acoustic Structure and Temporal Rhythm of Calls in Rhacophorus dennysi" was published in Asian Herpetological Research. (2012, 3: 205-212).