Navigation and spatial learning in Hermann's tortoises: Insights from geometric reorientation

Goal-driven spatial reorientation in rectangular arenas, with or without landmarks, relies on metric attributes and environmental cues aligned with left-right orientation. Although the phenomenon has been documented in several vertebrates, its mechanisms remain little explored; in reptiles, however, neither the phenomenon nor its mechanisms have been investigated. This study tested whether spatial geometry and exploratory strategies shape reorientation in Hermann's tortoise (Testudo hermanni). Individuals were trained in a rectangular arena to locate a food reward by selecting either two geometrically symmetric corners ("No Blue Wall") or a single corner marked by a blue landmark positioned nearby ("Blue Wall Near") or at a greater distance ("Blue Wall Far"). Tortoises successfully learned to reorient using both geometric and landmark information, adopting consistent strategies to reach the goal. Qualitative observations revealed lateralized wall-following routines and a preference for perimeter exploration. Quantitatively, tortoises in the "Blue Wall Near" condition executed fewer turns, moved faster, and reached the target more quickly than those in the "Blue Wall Far" or "No Blue Wall" conditions, indicating that close proximity to a visual cue enhances spatial efficiency. In contrast, when landmarks were absent, individuals relied more heavily on geometric properties of the arena, following longer and less direct paths. Moreover, the "Blue Wall Near" condition promoted edge-following behavior, suggesting that nearby boundaries further support navigation. These findings demonstrate that reptiles can flexibly integrate geometric and landmark cues during spatial reorientation, underscoring the role of movement in shaping spatial strategies and providing novel insights into the cognitive processes underlying navigation. (PsycInfo Database Record (c) 2026 APA, all rights reserved).