NO. 7 FLOCKS OF NEOTROPICAL BIRDS — MOYNIHAN 63 



Summer tanagers seem to be more nearly parasitic on their com- 

 panions in mixed blue and green tanager and honeycreeper flocks than 

 are any other birds commonly associated with such flocks. 



BANANAQUIT 



Bananaquits may play a rather important role in mixed flocks — but 

 only occasionally. They are often rather silent and inconspicuous. At 

 such times, they may occur in mixed blue and green tanager and 

 honeycreeper flocks without having much effect upon their companions 

 in the flocks. They may join and follow individuals of other species, 

 or be joined, followed, and supplanted by individuals of other species ; 

 but such reactions are not usually very common. 



During the breeding season, however, male bananaquits sing very 

 frequently, and territorial bananaquits (apparently of both sexes) 

 often engage in prolonged and noisy disputes. When bananaquits are 

 noisy, they are joined, followed, and supplanted by individuals of other 

 species much more frequently than when they are silent. They are 

 particularly likely to be joined, followed, and supplanted by green 

 honeycreepers. 



It is not very clear why green honeycreepers should react so vigor- 

 ously to bananaquits at times, as bananaquits do not resemble green 

 honeycreepers in appearance or voice. The explanation may be simply 

 that green honeycreepers react strongly to individuals of any other 

 species that are conspicuous, and feel free to approach bananaquits 

 because the latter are so much smaller than they are. Interestingly 

 enough, bananaquits do not seem to have evolved any special char- 

 acters for the primary purpose of either encouraging or discouraging 

 green honeycreepers. It is possible that most bananaquits do not 

 encounter green honeycreepers very frequently. Individuals of the 

 two species encounter one another fairly frequently in such environ- 

 ments as the clearing on Barro Colorado Island ; but bananaquits are 

 also very common in certain types of second-growth vegetation in 

 which green honeycreepers are rare or absent. Or perhaps the two 

 species have come into contact with one another only relatively 

 recently. 



Associations between bananaquits and green honeycreepers are very 

 seldom long sustained. This may be largely due to the fact that noisy 

 bananaquits tend to stop vocalizing when approached by green 

 honeycreepers. 



There were some indications that some or all of the bananaquits 

 on Barro Colorado Island tended to join and follow green honey- 



