NO. 5 THE YELLOW-RUM PED TANAGER — MOYNIHAN 7 



which might be transcribed as "Tzzheet." These notes are uttered by 

 adults of both sexes and by juveniles, most frequently by adult males. 

 With very few exceptions they are uttered only by individuals who 

 are isolated or alone, i.e. who have become separated (by a distance 

 of at least several meters) from their mates or other members of their 

 own social group. Unlike the melodious "Kioo" or "Klioo" Notes 

 they are uttered quite frequently at all times of the year and during 

 all periods of the day. 



There are many resemblances between these notes and the vocaliza- 

 tions of crimson-backed tanagers which were called "Plaintive Notes" 

 in Moynihan, 1962c. The two patterns certainly are nearly identical 

 in sound, especially when heard at a slight distance. In an earlier 

 paper (Moynihan, 1962a), both were transcribed as "Tseet." Sub- 

 sequent and closer observations, however, have revealed that the 

 "Tzzheet" Notes of yellow-rumped tanagers are usually slightly harder 

 and hoarser, with a more pronounced "buzzy" quality, than the 

 corresponding notes of crimson-backed tanagers. They are, in other 

 words, slightly more similar to typical Hoarse Notes in tone. 4 



It has been suggested that "Tseeet" Notes are produced by thwarting 

 of some gregarious motivation as well as several different types of 

 "friendly" motivation, including pairing and parental tendencies. 

 This may well be true of some or all "Tzzheet" Notes also, as they 

 seem to occur in almost exactly the same range of circumstances. 

 Both patterns may function as "summons," a means of calling in or 

 attracting mates and other members of the family or social group. 

 All these resemblances would indicate that the two patterns must be 

 closely related phylogenetically. 



"Tzzheet" Notes seem to be uttered more frequently on the average 

 than the corresponding notes of crimson-backed tanagers in similar 

 situations. They must have a comparatively low releasing threshold. 

 They also are uttered in series more frequently than are "Tseeet" 

 Notes, and many series of "Tzzheets" are much longer than any 

 series of "Tseets." Adult male yellow-rumped tanagers sometimes 

 utter long series of "Tzzheet" Notes at very regular intervals of 

 approximately the same length as the intervals separating "Kioo" and 



* The term "Plaintive" is not particularly suitable as a name for the crimson- 

 backed tanager notes. It was applied to them only because they were thought 

 to be strictly homologous with the Plaintive notes of other species. This may or 

 may not be correct (see page 8). In order to avoid confusion these crimson- 

 backed tanager patterns will be called simply "Tseeet" Notes throughout the 

 following discussion. 



