Invariants in configurational prey selection by Bufo bufo (L.)

Toads (Bufo bufo) are able to distinguish small stripes with axis orientation in the direction of motion (worm-like stripes) from those with axis orientation perpendicular to the direction of motion (anti-worm-like stripes). The configurational discrimination ability of the toad is, thus far investigated, largely invariant for (1) movement direction in the x-y plane, (2) direction of contrast--stripe against background--and (3) velocity of stripe motion.