Characteristics of spatial memory in pigeons.

Pigeons learned a delayed-alteration (DA) task in a T-maze. Very few trials were needed prior to accurate performance. Similarly, after little training the birds performed accurately with delays of 8-16 min. End-of-delay cues, possibly provided by the experimenter, response-based cues, and intramaze cues were all experimentally examined and rejected as bases for the birds' performances; pigeons appear to rely on spatial (extramaze) cues. Long-delay performances were undisturbed by changes in delay-interval stimuli (illumination shifts and transportation around the laboratory). Finally, birds were shown to acquire DA so quickly because of a potent tendency to avoid recently visited locations (i.e., a preexisting "win-shift" tendency). Characteristics of pigeon spatial memory thus include temporal persistence, resistance to retroactive interference, and a win-shift bias. In these respects spatial memory of pigeons parallels spatial memory of rats.