Neil Jones Neil at nwjones.demon.co.uk
Fri Dec 14 14:58:37 EST 2001

On 13 Dec, in article <3C195900.19D3 at mindspring.com>
     cherubini at mindspring.com "Paul Cherubini" wrote:

> > The point I want to make is if we want to find out more about how Monarchs
> > get here, we don't need people releasing them in arbitrary places to muddy
> > the waters.  
> Actually determining the natal source of the monarchs seen in the British
> Isles each fall is rather easy.  Just catch a few butterflies and determine the
> cardiac glycosides they contain. If they contain the cardiac glycosides of
> Asclepias syriaca milkweed it will prove they originated in the northerrn 
> USA or southern Canada.If they contain the cardiac glycosides of Asclepias 
> currassavica, it will suggest they originated in southern Europe or the
> Canary Islands.

This is an obviously false argument. It is almost impossible to catch these
butterflies. The number seen is usually very small and they only arrive in
numbers at rare intervals. Any released individuals would swap and ruin
any attempt at studying the migration here. 

> There are a three fundamental reasons why monarchs could not possibly
> fly across the Atlantic on their own:

> I. Monarch butterflies (like probably all butterflies) cannot maintain
>  sustained 
> flight at night (except in urban areas near lights).  45 minutes after sunset, 
> monarchs will plummet to the earth if tossed into the air even on a hot full 
> moon night.  

Actually butterflies can and do fly at night. They occasionally turn up
in moth traps. THere is a difference between active flight and being caught
up in a storm. 

> 2. Monarchs cannot rest on the surface of water more than a half
> hour without becoming waterlogged.

There is no need for them to settle.

> 3. Monarchs cannot maintain sustained flight in overcast
> weather below 50 degrees F (10 degrees C) or below about
> 32 degrees F (O degrees C) in sunny weather,  This rules
> out any chance they could be carried on the jet stream to Europe.
> Also, temperatures below about 24 degrees F are fatal to monarchs.

Monarch arrivals in large numbers are strongly associated with warm storm
fronts which arrive from the USA in the Autumn.(fall) They are also
associated with the arrival of rare birds.

> By contrast it is easy to imagine how Monarchs could cross the 
> Atlantic assisted by ships.  Monarchs that fly out or are blown out 
> over the Atlantic coast of the USA, could land on ships and then leave
> as they approached the British Isles a week later.

If this is the case then why are do they move in exact parallel with storm
fronts? Why if they are coming over in ships do they only arrive for a 
few weeks in the autumn when these particular warm storm fronts arrive?

> Bottom line is that releases of captive reared monarchs at events
> in England/Scotland/Ireland will not substantially interfere with the 
> ability of scientists to determine the origin of wild monarchs that 
> usually appear in these countries each fall .

To reiterate the point. It is ILLEGAL to release monarchs in the UK.

> Paul Cherubini

Neil Jones- Neil at nwjones.demon.co.uk http://www.nwjones.demon.co.uk/
"At some point I had to stand up and be counted. Who speaks for the
butterflies?" Andrew Lees - The quotation on his memorial at Crymlyn Bog
National Nature Reserve


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