Those few adults....

[Ron Gatrelle]

----- Original Message -----
From: "Kenelm Philip" <fnkwp at aurora.alaska.edu>
To: <leps-l at lists.yale.edu>
Sent: Monday, September 23, 2002 2:26 PM
Subject: Those few adults....


>
> In a recent posting on the Miami Blue, Ron Gatrelle said:
>
> > One has to remember that adult butterflies are only a small portion of
> > any species overall population.
>
> That's quite true if you pick the right time to make your census. Right
> after oviposition the population can jump to around 250 times the total
> number of adults. However, the survival of a species is critically
depend-
> ent on the number of _reproducing_ individuals. If there were indeed only
> 50 adults, the 12500 ova they produce is not the major factor in survival
> of the colony. For example, consider the case of only 10 adults (and thus
> 2500 ova). The sex ratio for the 2500 ova will almost certainly be near
> 50% male/female--but there is now a distinct possibility that the next
> generation of adults could be all of one sex--in which case those 2500
> ova are doomed. Think of butterfly adults as a bottleneck, through which
> the entire population must pass each generation...
>
> Ken Philip

Ken, your post is interesting from the subliminal aspect.  You are up north
where nothing is continual brooded and I in an almost subtropical situation
were many things are continual - even in winter.   Two comments.

First, the "Miami Blue" was what was up to bat and thus I was assumptive
when I should have made it clear that at any given time all phases in the
metamorphosis are present in large numbers at the Bahia Honda area.  So
there is no "bottleneck" in that situation.  As I said in an earlier post,
this has to be the densest population of "Miami Blues" ever documented.
Yes, quotes mean "so called".

Second, I do not feel any one stage of a leps life is the bottleneck phase.
I think that at each stage the risks are all equal.  The stationary egg to
the mobile adult.  Each has phase advantages and disadvantages.

Ron



 
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