no. 7 



FLOCKS OF NEOTROPICAL BIRDS MOYNIHAN 



IO - 



more birds of one species followed a bird of another species were 

 counted as single cases of interspecific following, as all but one of the 

 following birds may have been following the first follower. Thus, 

 the actual number of interspecific following reactions in the mixed 

 blue and green tanager and honeycreeper flocks on Barro Colorado 



Table 4. — Data from observations in and around the clearing on Barro Colorado 

 Island between November 10 and December 20, 1959 



Unambiguous interspecific following and joining reactions by tanagers, honey- 

 creepers, and warblers. (Interspecific joining as well as interspecific following 

 reactions by finches are omitted from this table because all such reactions observed 

 were ambiguous.) 



No. of Species following Species being followed 



cases seen and/or joining and/or joined 



3 Plain-colored tanager Palm tanager 



1 do. Red-legged blue honeycreeper 



1 do. Crimson-backed tanager 



19 Palm tanager Plain-colored tanager 



3 do. Blue tanager 



1 do. Green honeycreeper 



1 do. Red-legged blue honeycreeper 



1 do. Crimson-backed tanager 



5 Blue tanager Plain-colored tanager 



2 do. Palm tanager 



1 do. Chestnut-sided warbler 



4 Golden-masked tanager Plain-colored tanager 



1 do. Blue tanager 



3 Green honeycreeper Plain-colored tanager 



1 do. Bananaquit 



1 Red-legged blue honeycreeper Green honeycreeper 



1 Summer tanager Plain-colored tanager 



1 do. Palm tanager 



2 Fulvous-vented euphonia Plain-colored tanager 



1 Bananaquit Green honeycreeper 



1 Chestnut-sided warbler Golden-masked tanager 



54 



Island was certainly larger, and probably very much larger, than the 

 number of such reactions shown in the table. 



This table is set up with the following species shown on the left 

 and the species they followed shown (separately for each following 

 species) on the right. 



Table 4 is a partial list of both interspecific following and inter- 

 specific joining reactions observed on Barro Colorado Island. For the 

 purposes of this table, a bird was considered to have joined another 



