CALLS AS REINFORCERS IN BULLFINCHES

A perch-hopping operant was used to test the reinforcing effect on bullfinches of two classes of their vocalisations. Two reinforcement indices were computed for each individual, there was no correlation between these indices. For four out of six bullfinches tested with loud calls at least one of these indices was significantly high. None of the six bullfinches tested with distress screams had indices that differed significantly from the neutral values. Group data for the median rate of perching during operant levels, test and extinction sessions were interpreted to suggest a positively reinforcing effect of loud calls and a punishing effect of distress screams. Problems posed by the use of the perch-hopping operant are discussed. © 1979, Brill, All rights reserved.