Ecology, Population Density, and Translocation of the Snake-Eyed Skink (Ablepharus kitaibelii) in Westernmost Populations

Abstract

Westernmost population of the Snake-eyed Skink is found in Papuk, Croatia, and is the closest to the population from Ilok, Croatia. So far, the ecology of any of them has not been studied, and here, we document the variation between them. Furthermore, we estimated population density in Papuk using line transects, and quantitatively assessed its viability, i.e., chances for its survival under different scenarios; under current situation, with increased habitat, and with the negative effect of catastrophic events (e.g., forest fires, habitat degradation). Our study suggests that the climate between the two populations differs significantly, while other general requirements of the species remain the same in both locations. In the Papuk area we estimated the total population size from 5036 to 5483 individuals, with a relative density of 97 individuals per hectare. The population viability results suggest that the extinction of the Papuk population is likely to happen due to the negative trend in the number of individuals over 100 years. This implies that the population is not stable and under current condition shows the need for urgent conservation measures. We modeled two measures, 1) restoration of habitat via the removal of black pine plantations, and 2) translocation of the Snake-eyed Skink into two new habitats. Both methods rely on the increase of available habitat, and both were implemented in the study area. In 2014 an area of 900 m2 of black pine forest was removed, and in 2014 and 2016 we translocated 100 individuals per year (altogether 200 individuals) into new habitats. Monitoring data confirmed that the newly established subpopulations are present at both sites, and are reproducing, which could imply that our translocation might be successful.