An Analysis of the F1 Phase in the Pigeon's Pecking Movement

Abstract

During pecking, pigeons perform two distinct stop phases with their head, F1 and F2, which are hypothesized to represent respectively the pigeon’s decision to peck at a broad target area, and the calculation of finer details such as depth and size of a target. Our study was conducted to assess the function of these phases, with a focus on the decision making stop phase (F1). Pigeons were trained with operant conditioning to distinguish between two circular white stimuli: one surrounded by a red square and the other by a yellow square. Once the pigeon reliably chose the correct coloured stimulus, we made them increasingly similar in colour. If the F1 phase represents the decision to peck, then as the stimuli become difficult to distinguish, F1 durations should increase. The results show that pecking accuracy decreased as the two stimuli became more similar, allowing us to see that the decision had become more difficult for the bird. However, decision difficulty was unrelated to stop phase duration. The current results do not confirm our hypothesis that the F1 phase is where the decision to peck occurs. However, these results are based on preliminary data from a small sample size, and as such we are limited in what we are able to conclude. The decreased pecking accuracy as decision difficulty increased is promising, and while this pattern of increased difficulty was not exhibited in our F1 stop phase duration analyses, the trend may become pronounced as we continue to collect more data.