Pii: S0376-6357(98)00048-5

In Experiment 1 the behaviour of black-capped chickadees timing intervals of 12.5 or 37.5 s was studied using the peak procedure. Average rate of responding peaked near the trained FI on test trials, while the spread of the response distribution was larger for the longer FI. On individual trials, chickadees showed a break-run-break pattern of abrupt changes in rate of responding. These results, plus the pattern of means, standard deviations, and correlations found in start times, stop times, and durations of runs, were similar to those found in pigeons and rats. This suggests that birds and rodents use similar timing mechanisms. In Experiment 2, chickadees were tested with an interrupted FI signal. On such ‘gap’ trials, the chickadees, like pigeons but unlike rats tested under similar parameters, ignored the signal time elapsed prior to the FI interruption and reset the interval clock. © 1998 Elsevier Science B.V. All rights reserved.