Some factors affecting pigeons' visual tracking behavior

A novel delayed conditional discrimination procedure was used successfully to investigate some factors affecting pigeons' tracking of visual stimuli. Trials began with the brief illumination of one of the keys (randomly selected) from the left- or right-hand column of a three by three matrix of pecking keys. Then the next key in the same row was briefly lit. Finally, the remaining key in the row was lit along with one (randomly chosen) of the remaining five keys from the left- or right-hand columns. A peck to the former but not the latter key was designated as correct and was rewarded. In Experiment 1 pigeons made correct choices on between 70 and 80 percent of trials, thereby demonstrating an ability to visually track objects. In Experiment 2 tracking accuracy was: a) reduced when either the first or second key in the sequence was omitted, b) improved when the sequence was repeated three times, c) reduced when duration of key illumination was reduced, and d) reduced by delays imposed between keys early but not late in the sequence. It was also found that tracking of vertical and horizontal sequences was approximately equal.