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[[underline]] Cyanerpes [[/underline]] Mar. 12, 1958, III     (65)

[[image of bird with bill up, arrow to left leads to label "venter" arrow to right leads to female symbol]]
 This is a diagram of the situation during the redirected St's described on the preceding page.

    These incidents must indicate that the Bzz's are not overwhelmingly aggressive on the whole. They probably occur when attack and escape are nearly equal; the soft notes (SBzz) occurring when both the drives are weak, the load notes (LBzz) occurring when both the drives are strong.
    (This interpretation is not really contradicted by the amount of the fight between the first and second pairs a few days ago. The initial response of the first pair to the second pair was a rush forward and R -- and this must have been the most aggressive response -- although not the the highest intensity. The LBzz's -- ("L" I think) -- were the patterns that did precede attack during the highest intensity fights -- but these fights tended to be preceded by an infinitesimal pause while the 2 opponents stood face to face.)
     I wonder if the fact that the black throat is most prominently displayed during the less aggressive displays is in accordance with my interpretation of the valence of the black & blue colors in the Blue Honeycreepers? I think so. In the case of the Blues, it would seem that the raising of the most prominent blue feathers (i.e. the crown) is characteristic of a display which does not (to say the least) contain a very prominent escape element.