Fine scale behaviour and time-budget in the cryptic ectotherm European pond turtle Emys orbicularis

Area of Science:

• Ecology
• Animal Behaviour
• Physiology

Background:

• Ectotherm behavior and energy expenditure are directly influenced by thermal conditions.
• Global change necessitates understanding ectotherm time-budgets for adaptation assessment.
• Reproduction in ectotherms is energy-intensive, suggesting seasonal variations in energy expenditure.

Purpose of the Study:

• To test the hypothesis that energy expenditure in reproducing ectotherms peaks during nesting events.
• To analyze the fine-scale behavior, time-budget, and energetic costs of European pond turtles during their breeding season.

Main Methods:

• Eight adult female European pond turtles (Emys orbicularis) were equipped with data-loggers.
• Data-loggers recorded ambient temperature, pressure, light, and 3-axis acceleration over four months during the nesting season.
• Behavioral patterns and energetic costs were estimated based on recorded data.

Main Results:

• Turtles exhibited distinct daily activity patterns (Night, Morning, Midday, Evening).
• Activity levels were positively correlated with ambient temperature, particularly in the Morning before oviposition.
• Activity doubled during the nesting period, with increased Evening activity coinciding with nesting events.
• Basking behavior was influenced by air temperature and cloud cover.

Conclusions:

• This study provides initial insights into the seasonal time and energy budgets of the European pond turtle.
• Animal-borne accelerometers are effective tools for studying the behavior of free-living freshwater turtles over extended periods.
• Understanding these energy dynamics is crucial for predicting ectotherm adaptability in a changing climate.