Where do ninja tortoise live – Agility variation in Hermann’s torotises

Abstract

Armour of some terrestrial tetrapod's (e.g. tortoises, armadillos) confronts advantages of protection against predators with its negative effect on mobility. Although these animals typically live in flat environment, populations from rugged habitats are challenged to cross various obstacles in their daily movements. To examine variation in mobility of Hermann's tortoises, we set up identical agility experiments in two neighbouring populations from Prespa Lake region (FRY Macedonia). One population is at the rugged Golem Grad Island, covered with rocks and boulders, and the other is at the Konjsko village, characterized with gentle slopes covered with gravels and herbaceous vegetation. We observed the behaviour of both populations' adults throughout three tests: confronting the edge of a height obstacle (at 50 and 80 cm), as well as righting behaviour performance when overturned on their backs. We found significant behavioural differences in imposed situations, both between localities and genders. Animals from the rugged environment were more prone to jump from the height obstacles (especially convincing at 80 cm height), and were more successful in flipping back over to the upward position. In females from the flat habitat we found a negative correlation of body size with all measured performances (primarily righting). Differences in tortoise's time management during experiment occurred between localities just for one of the tests, possibly due to the thermal conditions. Considerable differences in agility observed between tested populations could be a result of the contrasting habitat configurations that these animals inhabit. In the rugged environment, tortoises are faced with negative obstacles on a daily basis and occasionally find themselves in an overturned position. Animals from the flat environment are possibly not as experienced. These findings could have conservational value, drawing attention to the importance of animals' familiarization with habitats' landscape configurations, especially when planning translocations.