Basking activity pattern of the European pond turtle, Emys orbicularis (Linnaeus, 1758) in Babat valley (Gödöllő, Hungary)

• Main Authors: Gergő Erdélyi, Borbála Szabó, István Kiss
• Format: Article
• Language: English
• Published: Pensoft Publishers 2019-10-01
• Series: Herpetozoa
• Online Access: https://herpetozoa.pensoft.net/article/39059/download/pdf/

The populations of the widespread European pond turtle and their numbers are decreasing in Hungary and other European countries. Knowledge of basking habits, along with other biological characteristics of the species, could be important to preserve the European pond turtle. The purpose of our research was to assess the seasonal and daily basking activity of the European pond turtle, and the effects of weather parameters on sun-basking, for which no prior data exist for Hungary. Our study was carried out in the area of a dammed valley pond system at Gödöllő (Hungary) over two years. The results showed that the seasonal peak of the turtles’ basking (the highest number of observed sun-basking turtles) was in the spring. When using a finer time scale (1.5-hour intervals), we found that daily activity peaks were earlier in the spring and summer (11:00–12:30 h) than in autumn (12:30–14:00 h). Based on three measured temperatures (air temperature in shade and sunlight, water temperature), the number of basking turtles positively correlated with temperatures and varied seasonally; the optimal temperature ranges also shifted during the year. In the spring and autumn, turtles started sun-basking at lower temperatures than in the summer. We observed the narrowest optimal temperature ranges in the summer as well. Based on a Principal Component Analysis of weather parameters, low humidity and high air temperature created optimal basking conditions, whereas high humidity, and low air and water temperatures had an adverse effect.