The relationship of age and Columba livia risk-sensitive decision-making in a spatial memory task

Recent studies suggest pigeons undergo age-related changes in hippocampal function and cognitive decline. The present research compared the behavior of six young and six old homing pigeons that were trained to locate food in an open-field task. The availability of the food varied by location between two different conditions: in one condition, the risky location (75% chance of food) yielded more total reward compared to a food bowl that delivered a small amount of food on all trials; in the other, the risky location (25% chance of food) yielded less total reward compared to a food bowl that delivered a small amount of food on all trials. There was no significant difference between the two experimental groups with respect to error rates (choosing an empty food location). However, while older pigeons preferred the small, constant reward location in both the low and high variable conditions, young pigeons only preferred the small, constant reward location in the low variable condition. In the high (75%) variable condition, younger, but not older, pigeons preferred the large, variable reward location, which yielded a larger long-term food gain. The behavior of the older pigeons indicates a deviation from rational decision-making and a greater aversion to risk. Further research will be necessary to probe how the avian hippocampus and related structures evaluate risk and reward, and how that evaluation may change as a function of age.