Pheasants Learn Five Different Binomial Color Discriminations and Retain these Associations for at Least 27 Days

Abstract

Individuals likely vary in how quickly they learn, how many different associations they may be able to maintain, and how long they can remember previously learned associations. However, it is unclear whether capacities for these cognitive processes are consistent within individuals, or whether individual performance differs when presented with novel variants of tasks, or across tasks that assess different cognitive abilities. We investigate associative learning and long-term reference memory in young (3-8 week-old) pheasants (Phasianus colchicus) using a series of visual binary discrimination problems that were presented at different intervals of time. Birds were sequentially presented with five novel color pairs, where they could learn that one color of each pair was consistently rewarded. After experiencing these learning trials, subjects were re-tested on each discrimination problem, but at different intervals (0-27 days), to assess their memory. Subjects' learning performance improved within 50 trials of each discrimination problem. We found no differences in performance between final learning sessions and initial memory sessions across the different time intervals, suggesting that pheasants retained the previously learned associations of multiple color pairs over at least a 27-day interval. Moreover, proactive interference did not impede their ability to recall subsequently learned color contingencies. Although individual learning and memory performance correlated positively, we found no evidence that individuals' performances were consistent across task variants. Our findings illuminate capacities for associative learning and long-term reference memory in pheasants.