Pigeons were trained on an analogue to a delayed matching-to-sample procedure requiring explicit, sample-specific, mediating responses during the delay. Each trial consisted of a three-link chain. The first and third links of the chain were the sample and choice components respectively of matching to sample. During the second link, different mediating pecks, dependent on the sample, were reinforced with the presentation of the choice component on a variable-interval schedule (VI 1.5 sec to VI 70 sec). Incorrect mediating pecks resulted in a timeout (TO). Matching accuracy during the third link was over 90% even with average delays of 70 sec, while accuracy of second-link mediating pecks tended to decrease as the delay interval increased. These findings were confirmed using fixed-interval and variable-time schedules during the second link of the chain. The results suggest that mediating behavior may function as a discriminative stimulus for correct choices under delayed matching to sample.