Radial-arm-maze behavior of the red-footed tortoise (Geochelone carbonaria).

The radial-arm maze is an established method for testing an animal's spatial win-shift behavior. Research on mammals, birds, and fish has shown that the mastery of this task is commonly mediated, to different degrees, by two types of strategy: those based on external cues and those based on response stereotypy. In the present study we trained four red-footed tortoises (Geochelone carbonaria) to navigate an eight-arm radial maze while providing different levels of access to visual room cues. The results indicate that response stereotypy is the more prevalent mechanism in these tortoises, although navigation based on landmarks can also occur if learned initially. The findings suggest that tortoise spatial navigation may be more similar to that observed in mammals and birds than previously thought.