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     THE NATURE OF CONSUMMATORY STIMULI & CONSERVATORY
     SITUATIONS, WITH SPECIAL REFERENCE TO SOME
     VOCALIZATIONS OF THE BIRDS
                    by

                 M. Moynihan
      (Canal Zone Biological Area, Panama Canal Zone)

                   INTRODUCTION

  The performance of certain behavior patterns, which have been called "consummatory acts" (see Lorenze, 1950), is usually followed by an obvious and rapid drop in responsiveness to stimuli releasing patterns, an apparent decrease of "internal motivation", "reaction specific energy", or "specific action potential".  The precise nature of this effect is still debatable (see, for instance, the discussion in Bastock and Blest, 1958), but it has usually been thought to be the direct and inevitable result of the mere performance of particular movements.  Bastock, Morris, and Moynihan (1953) have suggested, however, that it is not the performance of a consummatory act act alone which brings about the apparent drop in motivation, but rather the reception of certain"consummatory stimuli" during or after the act.
   Some vocal patterns of certain Central American passerine birds may be of interest in this connection; as they may be terminated by the reception of consummatory stimuli from the external environment without the performance of any activity which might be considered a consummatory act in the conventional sense of the term. 
    These patterns have been studied in several species on Barro Colorado Island and the mainland of the Panama Canal Zone, and adjacent areas in the Republic of Panama.
          
         DESCRIPTION OF AN APPARENTLY TYPICAL CASH

    The so-called "song" of the Blue Tanager (Thraupis episcopus)(underlined) may be taken as an example of the type of pattern to be discussed here. 
    The sound of this song has already been described by several authors (e.g. Eisenmann, 1952, Skutch, 1954). It consists of a moderately long and complex, but not very melodious, single phrase.