Climbing ability of European pond turtles sharply declines on slopes steeper than 36°: Implications for shoreline management

Abstract

Inadequate shoreline management might be detrimental to semiaquatic ground-dwelling taxa that utilize shorelines for migrations, basking and nesting sites. Although turtles are often associated with shorelines, limited knowledge of their climbing abilities hinders adequate management of these habitats. In this study we tested the climbing abilities of adult Emys orbicularis (N = 60) to explore the effect which artificial shorelines could have on their dispersal and habitat use. Over 90% of turtles were able to successfully climb a 36° slope. At steeper inclinations, female climbing success drastically dropped. Furthermore, climbing steeper inclinations is more time and energy consuming and might limit habitat use. Our results suggest that body size is the limiting factor of turtle climbing ability, regardless of sex. However, larger and less agile female turtles are especially susceptible to steep shorelines, since their fitness directly depends on their ability to reach favourable nesting sites. Based on our results, we suggest that slopes of artificial shorelines in European pond turtle habitats should not exceed 36° angles. Additionally, the shoreline surface should be textured (e.g. with grooves). Further studies should focus on locomotor abilities of other semiaquatic, ground-dwelling taxa (e.g. newts, toads, turtles), particularly as they pertain to obstacles around their reproductive centres.