Vanessa at night - migrations

[Kenelm Philip]

> Yes, Ken lots of people claims to have seen CLOUDS of migrating
> butterflies:

To my mind, there is a significant difference between someone reporting
'clouds of butterflies' (a rather vague quantitative measure), and a
number of different people reporting what they thought was a real
cloud in the distance, that later turned out to be composed of butterflies.

	I can also report from my own personal experience being on the
receiving side of the disbelief that an established scientist can have
for an 'anecdotal record'. Years ago I told Charles Remington that I had
found _Incisalia niphon_ on West Ridge, New Haven, CT. He informed me
firmly that I was mistaken--the species did not occur there. Fortunately
I was not one of _his_ students, so I held my own (and I still have two
specimens). But someone _could_ have forged the label data, so having
specimens that no one else saw collected could still be disbelieved by
someone whose mind was already made up...

	By the way, one mustn't omit the effects of wind on 'migration'.
In 1975 I was on Victoria Island (Canadian Arctic Archipelago). When I
arrived at our field site in the Kuujjua River valley (24 June) there were
no butterflies to be seen. On 27 June a single butterfly was seen at a
distance--then on 28 June one _Rheumaptera hastata_ (Geometrid) was
caught. One 30 June the first butterflies were collected--and on 1 July
a number of _R. hastata_ turned up along with more butterflies. No more
_hastata_ were seen after that, but the butterflies were out (weather per-
mitting) for the next month.

	Additional data are:

There was a major outbreak of _R. hastata_ in the taiga in 1975, both
in Alaska and in northwestern Canada. There was a prolonged period of
strong south wind as we arrived at our field site--which also occurred
in Alaska. Alaska Lepidoptera Survey volunteers picked up _hastata_ on the
coast of the Arctic Ocean that summer.

	All this indicates to me that these moths were picked up and
_blown_ a few hundred miles north from their usual haunts. I have never
heard of this species making long flights under its own power. Nor have
I ever heard of it emerging simultaneously with the earliest butterflies,
so I don't think the Kuujjua valley individuals emerged at that locality.

							Ken Philip
fnkwp at uaf.edu




 
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