Monarch Migration Predicted to be Extinct within 16 years

Paul Cherubini monarch at
Mon Oct 6 18:56:18 EDT 2003

Stan wrote:

> I have to question what Dr. Brower meant by "...normal..."  If his
> "normal" is a 10 year moving average,  and if (as an example) the
> average 11 years ago was three times what it was last year, saying it is
> "slightly above normal" could cause one to misinterpret this to mean the
> Monarch is doing very well.

The total size of the monarch overwintering population in Mexico
is determined by measuring the total forested area occupied by the 
butterflies.  Over the years, the total forested area occupied has been found
to range from 2 - 18 hectares and the average has been about 8 hectares 
(= 20 acres).

During the 2001-2002 overwintering season, the total area occupied
by the monarchs was found to be 9.6 hectares, so that is why Dr. Brower
said the size of monarch overwintering population was "slightly above 

Back in 1988-1991, however, Dr. Brower 
was predicting the extinction of the monarch migratory phenomenon
as early as the year 2000.  For example, here is what Dr. Brower
wrote in the journal "American Zoologist" in 1991:

In spite of this blunder, Dr. Brower continues to predict the 
extinction of the monarch migration, but has moved the date of
final demise up to the year 2019.

Paul Cherubini


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