Field studies of habituation: II. Effect of massed stimulus presentation.

Abstract

Recorded song was played to pairs of wild white-crowned sparrows [Zonotrichia leucophrys nuttalli]. Continuous recordings of all the behaviors elicited were made. Patterns of response depended on whether the female was brooding eggs, feeding nestlings or feeding fledglings, and on the behavior under consideration. Massing of songs played to pairs did not result in an increased response decrement. Successive tests of the same pairs in different breeding conditions resulted in a decreased responsiveness on the successive tests. Almost no spontaneous recovery occurred over periods ranging from 60 min to 15 days. The ineffectiveness of the additional trials are attributed to a general sensitization component that masks habituation. The data are discussed in relation to Thompson''s 2-process model of habituation.