The use of bioacoustics to assess the impact of environmental parameters on male pool frog (Phelophylax lessonae) call characteristics

The purpose of this investigation was to use current methods of bioacoustic analysis to determine whether the environmental parameters of water temperature and background noise significantly affect the characteristics of male Pelophylax lessonae (Pool frog) mating calls. The secondary purpose was to ascertain whether call characteristics (call length, pulse length, pause length, number of pulses, and peak frequency), are useful indicators of frog activity. This study was conducted during the predicted peak mating season, over a period of several months. Environmental readings of the study site were obtained using a variety of primary and secondary research, whilst frog calls were recorded using a microphone. Linear regression modelling was used to determine to what extent water temperature and background noise explained the variation in each call characteristic. Analysis of call characteristics produced results which suggested that call length, pulse length, pause length and number of pulses are significantly influenced by environmental parameters. As no relationship was found between peak frequency and the environmental parameters, alternative methods of study and predictor variables for peak frequency were put forward. It was also concluded that environmental parameters vary in their influence upon frog calls and that variance of each environmental parameter must be considered when studying their effect on frog calls. Emphasis is put on the great extent to which background noise influences call length and pause length, as this is a new development in the field of bioacoustics. Call characteristic analysis were found to be a very useful study method for several interactions, not limited to environment. The call characteristics which showed a relationship with the environment also proved to be useful indicators of frog activity, as frog activity is intrinsically linked to changes in in water temperature