612 U.S. NATIONAL MUSEUM BULLETIN 23 7 part 2 



The general tsip note seems to have different functions. It may serve as a 

 contact note between birds, especially birds of a pan-, as a protest note, or as an 

 alarm or warning note. Further study of this note may yet resolve it into at 

 least three different notes corresponding to the behavior induced. In other 

 words, although the tsip may sound the same to us, the variations in manner of 

 delivery or loudness may have meaning. 



The tsips of a female disturbed at the nest are immediately answered by her 

 mate and if her notes become hurried and excitable, he may come racing in to 

 her side, no matter what part of the territory he may be in. Both birds may then 

 utter loud tsips of protest at an intruder. The protest note invariably brings 

 neighboring towhees close to the nest in disregard of territorial boundaries. 

 Birds of other species are also attracted to the region of the nest in apparent 

 curiosity. 



The rapidly repeated tsip early in the morning is apparently the 

 means by which the male towhee announces possession of his territory 

 and its boundaries. He starts this tsipping while moving about over 

 his territory shortly after dawn starts to break, calling it from the 

 tops of bushes, boulders, and other song perches within the territory 

 at the rate of about 60 notes per minute. He continues this activity 

 untU sunrise and then stops. I have observed this behavior only 

 during the early part of the breeding cycle from mid-March to June 

 at Berkeley, and mid-April to June at O'Neals, Calif. 



During the nesting season the tsip note may be accentuated to a 

 tsink note which appears to function in the control and warning of 

 the young. It also serves to warn the female of danger while she 

 is on the nest. A faint sparrowlike tssp is used to keep in contact 

 with a mate when separated by shrubbery. Conditions of great 

 stress, such as attack by predators or handling by humans, produce 

 a loud squawking. When uttered by a young bird, this squakwing 

 acts as a distress signal that brings the parents rushing to the scene. 



One of the most interesting combination of notes is the brown 

 towhee's mate-call, which C. W. Quaintance (1941) describes as 

 follows: 



"To me, the basic tsip note is distinguishable in this particular 

 series of notes. The utterance sounds something like this: Tss' tss' 

 tss' tsurr tsurr tsurr, starting with fast staccato notes and getting 

 faster toward the end. Because these unique notes are given almost 

 exclusively between birds of a mated pair, they are referred to in this 

 study as mate-notes or as the mate-call." 



A casual observer seeing two birds fly into shrubbery uttering this 

 call might associate the notes with fighting. The observation of 

 banded birds allows only the interpretation of the mate-call as having 

 a "pair reinforcement" function. Quaintance (1941) continues: 



In most of these instances the meaning of the mate-call might have been 

 misconstrued if the whole action was not carefully followed. In over a hundred 

 recorded observations these mate-notes were given between members of a known 



