64 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I43 



creepers more frequently than they joined and followed individuals 

 of any other species of the blue and green tanager and honeycreeper 

 alliance. This may have been the result of conditioning. These par- 

 ticular bananaquits may have become used to green honeycreepers 

 simply because they were approached by the latter so frequently. 



OTHER SPECIES 



There is comparatively little to be said about the other species some- 

 times associated with mixed blue and green tanager and honeycreeper 

 flocks. Some of them were rather rare in the areas where these flocks 

 were studied. None of them appears to play a very significant role in 

 any appreciable number of blue and green tanager and honeycreeper 

 flocks, although some of them are very important in other types of 

 mixed flocks (see below). 



The streaked saltator and the yellow warbler may be cited as exam- 

 ples of rather common species that have very weak generalized gre- 

 garious tendencies and/or whose generalized gregarious tendencies 

 are usually very weakly stimulated by members of the blue and 

 green tanager and honeycreeper alliance. The differences between 

 the frequencies of interspecific social reactions by streaked saltators 

 and yellow warblers and by the other species cited in the accom- 

 panying tables may be taken as a rough measure of the extent to which 

 the latter species have become important social factors in the blue 

 and green tanager and honeycreeper alliance. 



PARTIAL SUMMARY 



Many mixed blue and green tanager and honeycreeper flocks are 

 rather complex societies. Each of the more common species of the 

 alliance tends to play a characteristic social role, more or less distinctly 

 different from that of every other species in the mixed flocks of the 

 alliance. These roles are the results of complex interactions between 

 each species and at least one (usually several) other species. Several 

 of the species tend to react differently to each of several other species. 

 Most of the more common species have also evolved special adapta- 

 tions, of plumage and/or behavior, to facilitate the performance of 

 their characteristic roles in mixed flocks. 



The most remarkable and apparently specialized social bonds be- 

 tween different species in mixed blue and green tanager and honey- 

 creeper flocks are the special interspecific preferences. 



Diagrams I and 2 are tentative summaries of the interspecific pref- 



