Young chickens learn to localize the centre of a spatial environment

Young chickens were trained to find food by ground-scratching in the centre of a closed uniform arena and were then tested in arenas of similar areas but of different shapes. Chickens showed localized searching behaviour in the square-shaped arena, and maintained this behaviour when placed in a circular or triangular (both equilateral and isosceles) arena. With a rectangular-shaped arena, obtained by doubling the original square-shaped one, chickens showed more dispersed searching along the major axis, but searching tended to be concentrated around the centres of the composing squares and around the centre of the rectangle itself. When trained in a square- or triangle-shaped arena and then tested in an arena of the same shape but a larger area, chickens displayed searching behaviour at two different distances from the wall of the arena, one corresponding to the correct distance (i.e. centre) in the smaller (training) arena, the other to the actual centre of the test arena. On the other hand, in a circular arena, chickens searched mainly at a distance midway between the radius of the small (training) and of the large (testing) circular arena. These results suggest that, during training, chickens encoded information on both the absolute and the relative distance of the food from the walls of the arena, the latter information being more accurate when the arena displayed identifiable features such as corners.