Ontogenetic shift of antipredator behaviour in Hermann’s tortoises

摘要: Armoured animals generally exhibit two main antipredator responses: They either flee or stay motionless, withdrawn in their protective armour. The transition between these threat reactions can be affected by the degree of armour sturdiness. Tortoise shell stiffness gradually increases through ontogeny due to ossification. Additionally, neonates do not benefit from parental protection. Thus, juvenile survival could rely strongly on behavioural adaptations. This experimental approach addresses effects age (size), morphology, sex and population origin strategies. Predator attack was simulated overturning individuals backs. Juveniles displayed bolder response comparing adults. also spent shorter periods time shells inspecting surroundings. Immature tortoises all localities had high self-righting success, contrary deterioration righting success coincides with sexual maturation. Prompt switch hiding fleeing strategy threatened implies that natural selection acts swiftness agility. Sexes did diverge displays. Self-righting speed correlated shape both juveniles Morphological measurements used this study only These were accompanied a general negative effect increase body size. Further studies should explore how frequency predator encounters (i.e. experience) behaviour tortoises. have conservation implications, especially for efficient releasing captive breeding programs.