•**Gallistel
has argued that choice ****behaviour in animals
mirrors ****reinforcement
contingencies
**•**“Every ****day two naturalists go out to a pond where ****some ducks are overwintering and station themselves ****about 30 yards apart. Each carries a sack of bread ****chunks. Each day a randomly chosen one of the ****naturalists throws a chunk every 5 seconds; the other ****throws every 10 seconds. After a few days experience ****with this drill, the ducks divide themselves in ****proportion to the throwing rates; within 1 minute after ****the onset of throwing, there are twice as many ducks ****in front of the naturalist that throws at twice the rate
of ****the other. One day,
however, the slower thrower ****throws chunks twice as big. At first the ducks ****distribute themselves two to one in favor of the faster ****thrower, but within 5 minutes they are divided
fifty-fifty ****between the two
â€śforaging patches.â€ť â€¦ Ducks ****and other foraging animals can represent rates of ****return, the number of items per unit time multiplied by ****the average size of an ****item” (Gallistel, 1990).**