Time-shared feeding and drinking

Barbary doves were tested in an operant situation in which they characteristically alternate between feeding and drinking. The experimental findings may be summarized as follows: (1) the cumulative distribution of the intervals between feeding bouts is little affected by reward rates; (2) a lock-on index is correlated with reward rate, but is not affected by altering reward rate per se, as long as the overall rate of ingestion remains the same; (3) when a primarily hungry animal is interrupted while feeding, or a primarily thirsty animal while drinking, the behaviour is resumed after the interruption; (4) when a primarily hungry animal is interrupted while drinking, or a primarily thirsty animal while feeding, the behaviour is resumed after a short interruption, but changes to the alternative behaviour following a long interruption; (5) titration of interruption period in the dominant region of the motivational state space is always stable, but becomes unstable if the dominance changes, or if the titrating criteria are reversed. From this evidence it is concluded that feeding and drinking can be time-shared in a manner analogous to that found in computers.