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26

Ramphocelus, Apr. 27, 1958, II                 

This certainly looks very aggressive.

I should not, in fact, be surprised if this ΦR turns out to be just the typical adult (male only?) for of R.

I have heard some PCN's like those of my captive bird in the group here; but only, so far as I know now, by females or immature birds.

I have now seen a male stand in the top of a tree and give a vocal performance of CN-CN-CN-ΦR - CN - ΦR - CN.  Some of these ΦR's sounded quite like the R's of my captive bird, except for the fact that they were so definitely higher & thinner.

The last notes of some (at least) of the triplet TssC's are brief Φ-type R's or have a rattle undertone.

The whole TssC is their reminiscent of an abbreviated R of the Summer Tanagers. This may indeed be its closest homologue!

The "ordinary CN" is certainly an ALCN in some cases, and possibly, I suppose, in all.


Ramphocelus, I             

April 28, 1958
Rio Chucunaque

Early this morning I watched another adult male standing alone & uttering triplet & quadruplet Tss C's. Just as before (This time without any ΦR notes or notes with rattle undertone). It is these calls which may be mostly strictly homologous with the "R"s of the Summer Tanagers. It is now obvious that the Tss C's are usually (but not always) uttered by somewhat isolated males and they may well be produced by some thwarted social or pairing drive and be designed