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Mixed Diglossini, May 5, 1965, IV.

[[margin]] Cy [[/margin]]  Then suddenly one bird flies straight toward the other.  The other flies, and both plunge down toward ground.  Only a foot or so above ground, they suddenly swerve and fly off into distance.  The downward plunge was accompanied by Twitters [[underlined]] without [[/underlined]] Intro Notes.  Another "Pounce" like incident!  "Pounces" may be characteristic of Diglossa???

NOTES:

I.  The Laf-like Songs heard around here definitely are uttered by Yellow-faced Whitestarts.  So the nature of the Black Diglossa-type seen the day before yesterday remains problematical.

[[margin]] Albi Cy [[/margin]]  II.  As far as my observations go, the territories of "Glaucs" and undoubted Albis are mutually exclusive.  And Cys are equally stratified over both.

[[margin]] Cy Gen [[/margin]]  III.  This morning's observation would suggest that the Cys are breeding here now.  Certainly the other diglossines are not.  This is not surprising.  I received the impression, in other parts of the Andes, that Cys bred twice a year.

IV.  If [[underlined]] glauca [[/underlined]] really is similar to [[underlined]] albilatera [[/underlined]] in ecology, habitat preference, etc., this might help to explain why [[underlined]] albilatera [[/underlined]] does not occur in the southern Andes.  I.E. [[underlined]] glauca [[/underlined]] takes its place there.  ([[underlined]] glauca [[/underlined]] may well have originated in the south.  It does not reach Venezuela.)

V.  The absence of overlaps between the Laf-like Songs of the Yellow-faced Whitestart and the Whistle Songs of the [[underlined]] Atlapetes [[/underlined]] (certainly [[underlined]] rufinucha [[/underlined]]) this morning was most interesting.  Perhaps this sort of mutual inhibition is widespread in birds???

[[margin]] Caer? [[/margin]]  VI.  Thinking it over, I can see absolutely no reason why Caers shouldn't occur here.  So perhaps the peculiar song heard yesterday near the top