Investigation of Environmental Changes on the Characteristics of Tree Frog (Hyla Savignyi, Audouin, 1827); Acoustic Production and Reproductive Effort in Male Sex

Understanding the evolution of life history requires analyzing the balance between the energy devoted to growth, development, and reproduction activities and how to adjust this balance to maximize lifetime reproductive success. On the other hand, advertisement calls play an essential role in the characteristics of life history, having a direct relationship with the activities of production and finally the success of the reproductive organ. Considering the effective role of environment on characteristics of amphibians, the main purpose of our study was to study the environmental variations of acoustic traits and reproductive investment in male populations of H. savignyi tree frog in central and western Iran. For investigating the production investment, testicular weight, and size along with body weight and length (SVL) traits in all populations of H. savignyi were studied at altitude range of 1000-2117 m. Moreover, for acoustic studies, five standard acoustic traits Call duration (CD), Inter-call interval (IC), Note duration (ND), Inter-note interval (IN), and Number of note per call (N/C) of this species were studied in different populations and temperature ranges. The study of quantitative testicular traits and traits related to body features (SVL and weight) showed a significant negative relationship in testicular weight and size with increasing altitude, while this relationship followed the opposite result for both SVL and weight, indicating a balance between growth and reproductive activities in this species. The results of comparison of advertisement calls showed that H. savignyi calls have a common structure in all populations. Moreover, the effect of temperature on acoustic parameters significantly (P≤0.05) reflected the determining role of temperature on all the studied acoustic characteristics..