The perching response and the laws of animal timing

Homing pigeons were trained under differential-reinforcement-of-low-rate (DRL) or differential-reinforcement-of-response-duration (DRRD) schedules using a perching response. Schedule values ranged from 10 s to 70 s for DRL and from 12 s to 40 s for DRRD. In general, mean interresponse times or response durations were very close to the schedule requirement at all schedule values. A linear relation between mean response measure and schedule value described the data well, but power functions fared even better. The data also conformed well to the generalized Weber law; standard deviations of response measures varied as a linear function of the mean. Overall, the perching response produced data that conformed much more accurately to the schedule requirement-particularly at the longer schedule values-than did data from previous studies with both rats and pigeons. The results conformed well to the linear-type timing consistent with scalar timing theory.