Viewing page 27 of 208

This transcription has been completed. Contact us with corrections.

(16)

Mixed Diglossini
May 4, 1965
Munchique

SEE TODAY'S NOTES ON GENERAL MIXED FLOCKS.

[[margin]] Cy [[/margin]]  Cys certainly are [[underlined]] not [[/underlined]] obligate commensals.  But today's observations would confirm the hypothesis that they are purely arboreal here.  Also that they are not nectarivorous here.

[[margin]] Albi Cy [[/margin]]  The ecological separation between Albi and Cy here seems to be very wide.  Possibly the [[male symbol]] Albi seen this morning fed as high in scrub as the lowest scrub visited by Cys.  But usually the two species are in quite different strata of vegetation.  This apparent stratification is perhaps remarkable in view of the fact that the altitudinal ranges of the two species overlap broadly here.  (I have never seen a Cy at quite such low elelvations as Albis;  but the Cys certainly come down to within a couple of hundred feet of the Finca area – see yesterday's notes.  And both certainly range up to the top of the mountain.)

[[margin]] Gen [[/margin]]  The separation between Diglossas here, on the whole, may be is great as that between species in Bolivia.  Does this affect my general hypothesis(es) in any way?  I think it must.  But how???

[[margin]] Gen [[/margin]]  Is it merely that contacts between species are least frequent where environmental conditions least favorable?  But Olivia did not seem to be unfavorable.  (The populations there were large, as I remember.)

[[margin]] Albi Cy [[/margin]]  (As I remember, I saw a number of contacts between Albis and Cys in the Sierra de Mérida in 1962.  And certainly the Cys in the Eastern Cordillera come down into low scrub visited by Albis, at least occasionally.  So the separation between Albis and Cys here must