Monarch Population Negatively Correlated with GE Acreage

[Paul Cherubini]

Mike Quinn wrote:

> ---The following is from Journey North---

> Some very concerning population estimates were recently 
> released from the Mexican over-wintering sites.  This winter's 
> population was the lowest since records have been kept. 

Mike, this isn't the first time the Journey North website has been
"very concerned" about low overwintering populations and not the first
time it has stated or implied that peak years are "normal years".

For example, in the Spring 1995 Journey North archives 
http://www.learner.org/jnorth/www/jn95/migrations/students/881597950.html
the following statement and table was presented:

"For the past few years, however, people have become very concerned 
about the west coast monarchs. The population has fallen drastically 
since 1991. This year there are 90-100% fewer at each site! The chart
below compares the normal population size to the size this year at the
3 largest sanctuaries:" 

                                          Normal Size        Size This Year 
                                                                 (winter of 1994-95)

Pismo State Beach , CA          180,000             15,000 

Ellwood Sites                          100,000               5,000 

Natural Bridges State Beach   170,000               4,000 

What's wrong with this? Well the 15 year average for Natural Bridges and 
Ellwood is actually around 60,000 and 5 year average for Pismo Beach around 
75,000. The170,000 figure was recorded only in one peak year (back in 1982)
and the 180,000 figure in one peak year (1991). Thus the public is left with a
highly distorted and worrisome picture of the situation.  One year later, in the
spring of 1996, Journey North had the opportunity to tell the public that the 
Pismo Beach colony was back above normal (140,000) and that Ellwood and 
Natural Bridges were back to long term normals, but did not to report this 
good news. Likewise, in the spring of 1998 Journey North had the opportunity
to tell the public that California populations were back to the peak levels
recorded in 1982 and 1990, but failed to mention this good news. 

Journey North data is misleading and worrying the public again this year by 
comparing estimates of the monarch populations measured in Mexico in recent 
years with only the peak population years measured in the mid-1990's.  A much 
less misleading and worrisome picture of the situation would emerge if Journey
North would post ALL the available census data for Mexico that goes back 
about 20 years. 

Paul Cherubini, Placerville, Calif.

 
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