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Mixed Diglossini, July 18, 1965, II  (72)

^[[Gen]] and both [[underlined]] carbonaria [[/underlined]] s.l. and [[underlined]] lafresnayei [[/underlined]] s.l. are very rare or absent. Both these assemblages also resemble the assemblage on the Farallones (which seems to differ only in lacking Coers).

^[[Gen]] These types of Diglossa faunas obviously are "marginal". 

Probably one of the reasons why these faunas are impoverished is the "excess" humidity of the regions in which they occur.

^[[Gen]] But humidity, by itself, is not a sufficient explanation. I don't think that Munchique, the Farallones, and the northern part of the Central Cordillera really are more humid than parts of Purace (or the Cordillera de Mérida) where other species of Diglossa (also) occur.

^[[Gen]] Probably the crucial factor is a combination of humidity and relatively little land at very high elevations (say, above 9000 ft).

Probably such species as [[underlined]] carbonaria [[/underlined]] s.l. and [[underlined]] lafresnayei [[/underlined]] s.l. cannot survive at relatively low elevations during particularly unfavorable (i.e. particularly humid?) years. But they can survive at relatively high elevations at such times. Thus, wherever there is a relatively large amount of high altitude land available, the populations of [[underlined]] carbonaria [[/underlined]] and [[underlined]] lafresnayei [[/underlined]] which survive periods of stress probably will be relatively large and can "easily" re-invade lower elevations when more favorable conditions return. When the amount of high land is small, however, the surviving populations may be so small that they may become extinct "by accident", and/or be so altered (eg, reduced variability and adaptability) that they are unable to re-invade the lower altitudes

^[[ [[underlined]] Conirostrum carbonaria - lafresnayei [[/underlined]] ]] The [[underlined]] diglossine [[/underlined]] fauna here in the northern part of the Central Cordillera, [[underlined]] now [[/underlined]], seems to differ from the corresponding faunas of Munchique and the Farallones in lacking (or almost lacking) [[underlined]] Conirostrum [[/underlined]]

Transcription Notes:
Moved "-ally," to end of previous page, per hyphenation rule.