butterflies, clouds, and wind

[DR. JAMES ADAMS]

Dear listers,

          Excuse me if someone has already posted with similar 
information.

           The one observation I would like to add to this discussion 
is the effect of cloud cover on flight of butterflies at high 
elevation.  I have been at or above treeline on several occasions in 
Colorado, enjoying watching flights of Parnassius, Colias meadi, 
several alpine satyrs, etc.  One of the most striking behaviors I 
have ever seen in butterflies in general is the almost immediate 
response to cloud cover -- namely, dropping to the ground.  I have 
seen Parnassius phoebus (smintheus?) drop literally the second the 
sun becomes obscured.  Even more impressive is their ability to 
"disappear".   I have more than once been nearly on top of a flying 
Parnassius when it has dropped to the ground as the sun goes behind a 
cloud.  I've dropped to the ground just seconds behind and be unable 
to find the butterfly in all but one occasion, even after seeing 
precisely where it went down.  I grant you, that most of the time 
this has happened the terrain has been a bit uneven and rocky, but 
they are able to pull this "disappearing" stunt even in open alpine 
meadows.

                   James

Dr. James K. Adams
Dept. of Natural Science and Math
Dalton State College
213 N. College Drive
Dalton, GA  30720
Phone: (706)272-4427; fax: (706)272-2533
U of Michigan's President James Angell's 
  Secret of Success: "Grow antennae, not horns"