has argued that choice behaviour in animals
•“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).