Vanessa at night - migrations

[Eddie John]

Apologies for getting these out of sequence, but I just noticed that I had inadvertently responded direct to Paul Cherubini yesterday.
 
Eddie 
-----Original Message-----
From: Eddie John <eddie at grayling.dircon.co.uk>
To: monarch at saber.net <monarch at saber.net>
Date: 03 February 2002 22:57
Subject: Re: Vanessa at night - migrations


Dear Paul
 
Concerning your comment..... ''This is not how the Painted Lady migration works in California and Arizona. The migration keeps going from dawn to dusk, day after day.''      
 
Yes, of course, this is what would happen with migration over land, but where there is no opportunity for the migrants to settle and feed they have no option other than to continue on their journey.  (See also my earlier posting, via Nick G-D, about Torben Larsen's prediction about cardui departing from Portugal and arriving in Ireland (T. B. Larsen, 1988. A migration of Cynthia cardui in Portugal. Entomologist's Rec. J. Var. 100:131 & pers. comm.).  Those that arrived in Cyprus in late afternoon were seen to settle for the night, whereas migrants that arrived earlier in the day passed straight through, showing no signs whatever of pausing to feed.  These were seen to leave in thousands from the north coast of the island.  How were they to know that the next landfall (Turkey, where they were observed coming in off the sea within the same period of days) is only 70 km away and attainable with relative ease?
 
and......."Cyprus is a big island - about 90 miles wide (150 kilometres). Were any human observers stationed at the southern tips or beaches of the island so that they could witness the incoming Painted Ladies arriving from the south out over the open water (Mediterranean sea) at dawn?  Did anyone take any pictures or video of this fantastic phenomenon?"     
 
It's actually about 200 km in length, but the migration took place roughly from south to north, i.e. across the width of the island, which ranges from a few metres (at the tip of the 'panhandle') to approx 80 km (at centre).  (Nice map, by the way, Paul.  Do you have a particular interest in Cyprus?).  Observers (human:-)) were indeed placed close to the southern shores but not, I am sorry to say, close enough to witness flight over open water.  Nevertheless, as I have pointed out, the migrants were not present the previous evenings so it is inconceivable that they could have covered the 340 km from Israel to Cyprus in the short time of available daylight before the first sightings at 07.40 hrs.  Do you agree?  Nor were any pictures or videos made - but, then, the discussion is about night-time flight:-)
 
Fantastic?  Have faith - it happens!  D. Benyamini will be summarising numbers of migratory sightings in a paper 'Butterfly Migration in the Middle East' in Linneana Belgica 18 (in press) 2002. There, another reference for you:-)

Eddie
    -----Original Message-----
    From: Paul Cherubini <monarch at saber.net>
    To: Leps-l at lists.yale.edu <Leps-l at lists.yale.edu>
    Date: 03 February 2002 21:21
    Subject: Re: Vanessa at night - migrations
    
    
    Eddie John wrote:
    
    > For example, do they accept the ability of V. cardui to
    > cross large stretches of open water i.e. distances that 
    > require at least part of the migration to be undertaken 
    > at night?
    
    Yes, there are those of us who are unconvinced Vanessa
    butterflies are functionally capable of migration one hour
    or more after sunset or one hour or more before sunrise.
    
    > Large numbers of incoming cardui were
    > seen, in full migratory flight, heading northwards from the south coast of
    > Cyprus from early in the morning, on several successive mornings. 
    
    Yes, we agree cardui actively begins migrating about 15-30 minutes
    before sunrise. I have witnessed this first hand during Painted Lady
    migrations in California. I have seen Painted Ladies vibrating their
    wings about 15 minutes before sunrise, getting ready for take off.  
    
    > There had been NO build up of numbers on any of the previous
    > evenings, so they had not already arrived in daylight hours the 
    > previous evening - the bulk of the migration for that day having 
    > already passed through.
    
    This is not how the Painted Lady migration works in California
    and Arizona. The migration keeps going from dawn to dusk, day
    after day.  
    
    Cyprus is a big island - about 90 miles wide (150 kilometers).
    http://www.mindspring.com/~cherubini/cyprus.jpg
    Were any human observers stationed at the southern tips or beaches
    of the island so that they could witness the incoming Painted Ladies arriving
    from the south out over the open water (Mediterranean sea)
    at dawn?  Did anyone take any pictures or video of this fantastic 
    phenomenon?
    
    Dr. Adrian Wenner, an insect behaviorist, has a slogan of sorts I like
    "fantastic claims require fantastic evidence".
    
    Paul Cherubini
    Placerville, California
    
    
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