Population dynamics of amphibian community in Lake Çıldır, Northeastern Anatolia

Abstract

Knowledge on life history traits and population dynamics of amphibians from northeastern Anatolia is limited. This results in a heavy reliance on published data regarding the European and Caucasian counterparts of the Anatolian populations in local conservation studies. The present study evaluated the phenology, age structure, population size, and population structure of the amphibian community in Lake Çıldır, northeastern Anatolia, Turkey. The site was surveyed between April 2017 and July 2019, detecting the presence of Bufo verrucosissimus, Bufotes viridis sitibundus, Pelophylax ridibundus, and Rana macrocnemis. The estimated population size ranged from 553 to 789 individuals for P. ridibundus and from 404 to 655 individuals for R. macrocnemis. The estimated mean capture probability was 0.09-0.10 for P. ridibundus and 0.08-0.11 for R. macrocnemis. The mean survival rates were estimated at 0.40-0.60 for P. ridibundus and 0.24-0.56 for R. macrocnemis. A male-biased sex ratio was observed for all species. The mean age was estimated at 5.28 years (2-9) for P. ridibundus, 4.32 years (2-6) for R. macrocnemis, and 5.55 years (3-9) for B. viridis sitibundus. Depending on weather conditions, the amphibian species emerged from brumation in the second half of April, and the breeding period took place between the end of April and June. The metamorphosis was attained in 55-125 days for P. ridibundus, 44-124 days for R. macrocnemis, and 56-128 days for B. viridis sitibundus, depending on weather conditions. The amphibian community of Lake Çıldır comprises healthy frog and toad populations, whose primary threats appear to be weather fluctuations and climate change. In contrast to their western Anatolian conspecifics, the studied amphibians suffered limited habitat loss and degradation, rendering them effective candidates as indicator species for climate change studies.