Viewing page 31 of 114

This transcription has been completed. Contact us with corrections.

Cyanerpes, Jan 20, 1958 II (31)
[3-line and squiggle highlighting]
by a general suppression of weakengin of the hostile dives, a peculiar modificatoin or general raising of the releasing threshold levels.
   But it should also be noted that the HCN's (and CN's, I think) and CR of the visitors are far more often given by birds sitting in the trees some distance from the aviary than by birds actually perched on the aviary itself  This might suggest that such manifestations of "un-overt" hostility are suppressed by too close appreach to another bird!  How is this achieved?  By increase of the escape dive?  But birds perched on the aviary don't show any overt regris[?] of stronger escape than birds in the trees.
[end of 3-line and squiggle highlighting]
[begin 3-line and squiggle highlighting]
   Perhaps I should modify the above statement a little, in view of the fact that I have just been watching more adult [male symbol]'s in full nuptial plumage making visits  These visitors were quite silent when perched on the aviary -- in spite of the fact the captive birds did utter a lot of HCN's -- but they did sit with CR (or at least crest feathers raised) -- and even, in one case, with the breast &belly feathers rather fluffed (this looked almost like a completely relaxed sitting posture)  These visitors were not, however, very close to the captive birds inside the cage; so the smoothing of the crown feathers may be only characteristic of cncounters when birds are literally face to face only a few inches apart.
[end of 3-line and squiggle highlighting]
[begin 3-line and squiggle highlighting]
   It is also barely conceivable that the HCN is not a hostile pattern at all, but a gregarious pattern; the resultof "frustrated"  gregariousness, and attempt to "call in" another bird.
[end of 3-line and squiggle highlighting]
[begin 3-line and squiggle highlighting]
   Most of the wild flocks I see seem to contain an excess of [male symbol]'s.  Is this real or deceptive?  And I think that visiting  [male symbol's are