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[[circled]] 22 [[/circled]]

[[underline]] Ateles [[/underline]] ssp., Jun. 24, 1959, V. 

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sible that the voice of the Red [[male symbol]] is just slightly shriller than that of the Blacks). All the animals open & close their mouths during Ord B. The mouth is opened wider, I think, than during MFB performances; and the Ord B is apparently not accompanied by PL. 
These Ord B performances are presumably strictly homologous with the RBB of the adult Woolly I watched in the Lima Zoo. 

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The Black [[male symbol]] has also performed quite a lot of what I called "Agg B" in my earlier notes. Single notes or short series of notes.  The individual notes are deeper in pitch than any MFB or Ord B notes. The number of notes in a single series seems to be quite variable. Seldom more than six or so. Never uttered as rapidly as the Ord B notes.  Frequently accompanied by Jud and/or BT. Frequently uttered as the animal advances, running or walking toward me.  Obviously aggressive, probably varying from moderate to moderately high intensity. The Black [[male symbol]] has also frequently performed silent BT, without Agg B, with or without Jud, toward me.  Frequently associated or alternated with Agg B patterns. Probably produced when attack is as predominant as it is during the Agg B patterns; but both the attack and any counteracting motivation are both weaker than they are during the AggB. 
The BT pattern of this species is fairly distinct morphologically. The corners of the mouth are drawn back, but not as far as in the BT of the White face. The upper teeth are not displayed by the BT; but the lower teeth are usually or always quite conspicuous. The mouth is always or usually kept moderately open throughout silent BT. Perhaps kept moderately open throughout BT with Agg B, perhaps showing a tendency to close partly between notes. (It is possible that I will eventually have to distinguish between 2 separate patterns, "pure" BT and "MO" - mouth