NO. 5 THE YELLOW-RUMPED MANAGER — MOYNIHAN 13 



Figure 1 is an attempt to show the relationships between the more 

 common and easily recognizable vocal patterns of adult male yellow- 

 rumped tanagers in diagrammatic form. 



Of all the nonvocal display patterns of yellow-rumped tanagers, 

 perhaps the most interesting and complex are the feather-raising 

 patterns. Yellow-rumped tanagers apparently do not have any general 

 ruffling pattern, involving all the head and body plumage simulta- 

 neously, like that of crimson-backed tanagers. Instead they have a 

 variety of patterns of more limited extent. These include Head- 

 ruffling, Head-fluffing, Back-ruffling, and Belly-fluffing. Tail- fanning 

 may be associated with the same group of patterns. It will also be 

 convenient to consider a special form of depression of the feathers, 

 Crown-flattening, in connection with some of the feather-raising 

 patterns. 



All these patterns seem to be ritualized. With the exception of 

 Tail-fanning, they seem to be performed only by adult males. 



Back-ruffling is a more or less extreme raising of all the yellow 

 feathers of the lower back and rump. The feathers are raised in such 

 a way that their tips are conspicuously separated. The wings 

 usually are drooped (but not spread to any appreciable extent) at 

 the same time. Back-ruffling is a very common pattern. It occurs in 

 a wide variety of social situations, but it seems to be much more 

 closely linked to aggression than to any other kind of overt unritualized 

 activity. It is frequently performed by attacking birds before and/or 

 after delivering attacks. It may be silent or accompanied by vocaliza- 

 tions. By far the most common vocalizations associated with Back- 

 ruffling are rattling patterns, all types of rattling patterns, including 

 "Tzzheet" — Thin Rattle — Hoarse Flourish performances. All this 

 would suggest that Back-ruffling is primarily an expression of the 

 attack tendency. Various kinds of Back-ruffling performances are 

 illustrated in figures 2 to 6 in conjunction with some notes on the 

 circumstances in which they were observed. 



Belly-fluffing is a raising of all the feathers of the lower breast and 



closing his bill while his throat went in and out, just as if he were uttering 

 many notes in rapid succession; but I could not hear any sound at all during 

 the performance, even though I was less than five feet away from him at the 

 time. His whole performance was very reminiscent of the initial stage in the 

 development of "Juvenile Subsong" or "Whispering Warbles" in young male 

 crimson-backed tanagers. Most of the other male yellow-rumped tanagers in 

 the same area at this time were molting from juvenal plumage into adult 

 plumage. It is possible that the male which performed "silent song" had just 

 completed the molt into adult plumage and was still behaving as a young bird. 



