Jp. Roche et al., ASSESSMENT AND CHOICE - AN OPERANT SIMULATION OF FORAGING IN PATCHES, Journal of the experimental analysis of behavior, 66(3), 1996, pp. 327-347
Pigeons were presented with an operant simulation of two prey patches
using concurrent random-ratio schedules of reinforcement. An unstable
patch offered a higher initial reinforcement probability, which then d
eclined unpredictably to a zero reinforcement probability in each sess
ion. A stable patch offered a low but unvarying reinforcement probabil
ity. When the reinforcement probability declined to zero in a single s
tep, the birds displayed shorter giving-up times in the unstable patch
when the ratio between the initial reinforcement probabilities in the
unstable and stable patches was greater and when the combined magnitu
de of the reinforcement probabilities in the two patches was greater.
When the unstable patch declined in two steps, the birds behaved as if
their giving-up times were influenced heavily by events encountered d
uring the most recent step of the double-step change. This effect was
observed, however, only when the reinforcement probability in that ste
p was .04, not when it was .06. All of these data agree with the predi
ctions of a capture-probability model based on a comparison of the est
imated probability of receiving a reinforcer in the current patch with
that in alternative patches.