DISPLAY PATTERNS OF TROPICAL 



AMERICAN "NINE-PRIMARIED" SONGBIRDS. 



IV. THE YELLOW-RUMPED TANAGER 



By M. MOYNIHAN 



Director, Canal Zone Biological Area 

 Smithsonian Institution 



This is the fourth in a series of papers on the behavior of some 

 neotropical finches, tanagers, and honeycreepers. It is largely con- 

 cerned with the behavior of yellow-rumped tanagers observed under 

 natural conditions in the Canal Zone, central Darien, and along the 

 Atlantic coast of the Republic of Panama, between April 1958 and 

 November 1962. 



Earlier authors (e.g. Eisenmann, 1955) usually refer to these birds 

 under the name Ramphocelus icteronotus. Recently, however, Sibley 

 (1958) has shown that yellow-rumped tanagers interbreed with the 

 birds usually called R. flammigerus on the western slopes of the 

 western cordillera of Colombia. He suggests that the two forms are 

 conspecific. If so, yellow-rumped tanagers should be known as R. 

 flammigerus icteronotus. 



The behavior patterns of yellow-rumped tanagers will be com- 

 pared with the corresponding patterns of related species described 

 in earlier papers of this series, especially the crimson-backed and 

 silver-billed tanagers, R. dimidiatus and R. carbo (Moynihan, 

 1962c), and the brown-capped and sooty-capped bush-tanagers, 

 Chlorospingus opthalmicus and C. pileatus (Moynihan, 1962b). All 

 behavioral terms will be used in the same sense as in these earlier 

 papers unless specifically stated otherwise. 



Yellow-rumped tanagers are common in many parts of central and 

 eastern Panama. Some aspects of their ecology and general social 

 behavior in this region have already been described in Moynihan, 

 1962a. Probably the most remarkable feature of their general social 

 behavior is their high degree of intra-specific gregariousness. They 

 are much more gregarious among themselves than are crimson-backed 

 tanagers in the same region. During the nonbreeding season they 



SMITHSONIAN MISCELLANEOUS COLLECTIONS, VOL. 149, NO. 5 



