Decline of the Levantine Frog, Pelophylax bedriagae Camerano, 1882, in the western Aegean Region of Turkey changes in population size and implications for conservation

Abstract

We estimated the annual population size, survival rates and capture probabilities for two populations of the Levantine Frog, Pelophylax bedriagae, using a Capture-Mark-Recapture (CMR) non-invasive digital photographic identification technique in Karagöl Lake and Soğan-harımı Pond in the western Aegean Region of Turkey, and used POLLOCK’s methodology to assess population parameters. Time specific capture probability, time specific survival rate and no temporary emigration were found to be the best appropriate models for our data. Population sizes were estimated as 245 adults in 2006, 301 in 2007, 67 in 2008 and 54 in 2009. Annual capture probabilities were estimated on average as 0.161, and annual survival rates across years were on average 0.301. Soğanharımı Pond was destroyed for recreational purposes after the first year of our study. To determine the size of the population, which was depleted during the construction of the recreational facilities, we used a closed population model, and concluded that in total 54 adults disappeared. In addition, we determined the possible negative factors that affect the population size and survival rates of the Levantine Frog including habitat destruction and the introduction of Siluris glanis and Astacus leptodactylus into the freshwater body.