Choice and foraging: the effects of accessibility on acceptability.

Pigeons responded in a successive-encounters choice procedure in which accessibility of the less profitable of two outcomes varied either in terms of probability of encounter or search time to encounter (keeping search time to the more profitable outcome constant). When the less profitable outcome was made more probable its acceptance became more likely. However, when search time to encounter the less profitable outcome was shortened, its acceptance became less likely. Both results are consistent with the delay-reduction hypothesis and with an optimality model developed for application to the successive-encounters choice procedure.