Here we compare whether birds encode surface
geometry using principal axes, medial axes or
local geometry. Birds were trained to locate
hidden food in two geometrically identical corners
of a rectangular arena and subsequently
tested in an L-shaped arena. The chicks showed
a primary local geometry strategy, and a secondary
medial axes strategy, whereas the pigeons
showed a medial axes strategy. Neither species
showed behaviour supportive of the use of
principal axes. This is, to our knowledge, the
first study to directly examine these three current
theories of geometric encoding.
