Meteorological variables affecting onset and duration of calling in Hyla arborea L. and Bufo calamita calamita Laur.

It was the aim of this work to investigate the effects of meteorological factors on two types of behavior related to vocalization in two species of anuran amphibians (Bufo calamita and Hyla arborea). The measurements were carried out in two gravel pits in the Kanton of Zurich. Evaluation by multiple linear regression was carried out at the computer Center of Zurich University. It could be shown that water temperature at 1900 was the most important factor for the onset of callings in both species. Air pressure (for both species) and amount of rainfall on the previous day and shunshine on the same day (for Bufo calamita) played a less important but significant role for this type of behavior. In both species, water temperature at 2400 was the important factor for the duration of the mating chorus. In addition, the amount of rainfall on the previous day and sunshine on the same day had a slight but significant effect on this type of behavior in Bufo calamita. The validity of the method and the results are discussed.