Influence of Urbanization on the Populations of the European pond Turtle Emys orbicularis (L., 1758) in the City of Plovdiv (Bulgaria)

Landscape change associated with urbanization presents a great challenge for conservation, because of the way it affects biodiversity. Turtles represent a very important component of the urban ecosystems. The European pond turtle, Emys orbicularis (L., 1758) is one of the two native aquatic turtle species, occurring in Bulgaria, including the city of Plovdiv, which is the second largest city in the country and its territory covers mainly the urbanized environment and adjacent terrains. According to the data for the last 100 years, the European pond turtle in the studied region is increasing its distribution range within the city, due to the development of dense system of irrigation canals. The presence of the invasive species Trachemys scripta elegans was registered in the region of Plovdiv City. The abundances and average density of the populations are relatively low and the age structure of the population of E. orbicularis from Maritsa River has the highest percentage of adults and juvenile individuals, indicating that the population of this species in the city is unstable. The main threat to European pond turtle in Plovdiv City is the anthropogenic factor, which is mainly through the loss of suitable habitats on the one hand and the direct destruction of specimens on the other.