Moving in the real world: tortoises take the plunge to cross steep steps

Abstract

Despite exhibiting low velocity and limited agility, many tortoises undertake large scale movements and must overcome various obstacles, notably in populations living in hilly or rocky habitats. Although crucial, studies exploring how tortoises move in complex and irregular environments are scarce. In this context, we examined an important behavioural trait: how tortoises (Testudo hermanni) deal with step-like obstacles. In their natural habitat, individuals were positioned in a challenging situation: they were placed on a bench approximately 50cm high, and were observed over a 10-min period. We compared the behaviour of the tortoises (taking a risk to jump' or waiting) from two populations living in contrasted habitats: flat versus rugged (crisscrossed by cliffs and rocky steps). Individuals from the flat habitat were reluctant to jump, whereas most tortoises from the rugged habitat jumped. Immature tortoises were less willing to jump compared to larger and more experienced adults. These results suggest that challenging habitats increase boldness. In addition to fundamental findings, these results may have conservation value and assist in improving translocation strategies for endangered tortoise populations.(c) 2013 The Linnean Society of London