A Computational Model for the Study of Release Call in the Pyrenean High Mountain European Common Frog (Rana Temporaria)

The aim of this study was to develop a computational model to perform a bioacoustic characterization of the release call of a high-mountain population of Rana temporaria. We also wanted to determine the way in which variation in specific anatomical structures, such as the nostrils and mouth cavities, affected call structure. For this purpose, we recorded induced release calls, above- and underwater, of individual frogs all over our research area as well as additional biometric data in the form of photographs, radiographs and video recordings. The data collected were used to create a virtual synthesized call that could replicate them, taking into account the variation introduced by the natural anatomical structures. Our model successfully replicated the recorded calls. We determined the role of mouth cavity acting as a Helmholtz resonator, both above and underwater, which suppressed certain frequency groups in order to highlight those with biological relevance. We also determined the role of the nasal cavities, which acted as a tube resonator amplifying specific frequencies during above-water vocalizations. The nasal cavity remained closed and therefore did not act as a resonator during underwater vocalizations.