“Can Domestic Fowl, Gallus gallus domesticus, Show Self-Control?” S.M. Abeyesinghe, C.J. Nicol, S.J. Hartnell, and C.M. Wathes, Animal Behaviour, vol. 70, no. 1, July 2005, pp. 1–11. The authors, at the Silsoe Research Institute in Bedford, U.K. and at the University of Bristol, report [AIR 16:1]:
An important aspect of cognition is whether animals live exclusively in the present or can anticipate the future…. We investigated self-control for food in domestic fowl using a standard two-key operant task and an equivalent two-choice return maze task…. While hens were impulsive in the standard condition, they showed significant and pronounced self-control in the jackpot condition, eliminating the possibility of an absolute cognitive constraint. Impulsive behaviour can instead be explained by… perceived depreciation of reward value as a function of the uncertainty associated with delay.