Vanessa at night - migrations

[Kenelm Philip]

> that would still equal enough space for 111,111 monarchs!

OK, now let's see if there has ever been a recorded case of over 100,000
butterflies alighting on a single ship, and staying on that ship for
a few days. Remember that ships didn't travel all that fast in the
late 1800s.

Then, let's 'take a mathematical approach to the problem'. 100,000 _Eurema
lisa_ flying 12" apart would make a tiny cloud around 60 feet in diameter--
rather like a hot-air balloon. I doubt that such an aggregation would have
appeared to be a real cloud in the distance. If the butterflies were
spaced far enough apart to achieve the volume of a cloud, their optical
depth would have been too small to see at any distance with the naked eye.
So there must have been a _lot_ more than 100,000 butterflies. And a lot
of ships? Has anyone _ever_ seen a fleet of ships vomiting forth millions
of butterflies? What an opportunity for a National Geographic photographer!

							Ken Philip
fnkwp at uaf.edu




 
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