DO SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 143 



It is possible that red-legged blue honeycreepers have begun to 

 evolve certain characters to increase their attractiveness to other 

 species. This might be one of the functions of the dull "eclipse" 

 plumage of the males during the nonbreeding season. The males of 

 other species of honeycreepers do not have eclipse plumages, and that 

 of male red-legged blue honeycreepers is really quite remarkably 

 similar to the year-round plumages of both male and female plain- 

 colored tanagers and palm tanagers (and the eclipse plumage of 

 male scarlet tanagers, Piranga olivacea) ." 



Male red-legged blue honeycreepers show more intraspecific gre- 

 gariousness than do females; and they also seem to occur in mixed 

 flocks relatively more frequently than do females. 



BLUE DACNIS 



Blue dacnises were not very common in any of the areas where 

 mixed blue and green tanager and honeycreeper flocks were studied ; 

 but they appeared to contribute appreciably to the cohesion of mixed 

 flocks, at least predominantly honeycreeper flocks, whenever they 

 occurred in such flocks. They seemed to join and follow individuals 

 of other species (especially red-legged blue honeycreepers) relatively 

 frequently; and they were also joined and followed by individuals of 

 other species (especially green honeycreepers) relatively frequently. 



CRIMSON-BACKED TANAGER 



All the species discussed above (with the possible or probable 

 exception of the shining honeycreeper) may be considered regular 

 members of mixed blue and green tanager and honeycreeper flocks. 

 They are regular in the sense that they tend to associate with one 

 another whenever a suitable opportunity to do so occurs, at least 

 during the nonbreeding season. Each of these species usually ap- 

 proaches, or is approached by, at least one of the other species 

 whenever they encounter one another during the nonbreeding season. 

 Individuals of these species usually prefer to associate with individuals 

 of other species of the group even when they have a wide choice of 

 alternatives, i.e., when it would be just as easy for them to associate 

 with individuals of species of other groups that have more or less 

 similar insectivorous and/or f rugivorous habits. 



11 The scarlet tanager is also the only species of its genus that has a com- 

 plete eclipse plumage. It would be interesting to know if scarlet tanagers asso- 

 ciate with mixed flocks in their winter quarters in the Tropics, and, if so, in 

 what capacity. 



