Fw: Interesting ...
Paul Cherubini
monarch at saber.net
Wed Apr 17 18:48:01 EDT 2002
Mark Deering wrote:
> As to your divergence to others statements and thoughts
> on Monarch populations, why do you not care if so many
> Monarchs died in the first place? Would not the population
> have been that much BETTER had they lived?
I agree Mark, but I am unaware of any case history evidence
that indicates there is a certain forest canopy structure or
density that can prevent mass monarch mortality during severe
winter storms in either Mexico or California.
For example, lets look at what happened this past winter. On Feb
14, 2002 Elizabeth Howard announced the following sensational
news on the Journey North website:
http://www.learner.org/jnorth/spring2002/species/monarch/Update021402.html#Single
Single Storm Kills Over 75% of Eastern North America¹s Migratory Monarchs
"Sierra Chincua Sanctuary: 74% of the butterflies were killed
El Rosario Sanctuary: 80% of the population was killed. Significantly,
these two huge colonies are the winter sanctuaries of 2/3 of eastern
North America¹s migratory butterflies. The other 1/3 of the butterflies
are spread among other smaller sites in the vicinity. While scientists
have not yet visited these outlying sites, mortality rates are feared to
be similar because the sites are small, their forest habitat is less pristine,
and because the rain and cold were prolonged in the region."
Now the crucial question at hand is did more monarchs die at
these outlying colonies "because the sites are small, their forest
habitat is less pristine, and because the rain and cold were prolonged
in the region" ??
Mark, In fact just the OPPOSITE occured. After the storm Dr. Robert
Cook, a Wildlife Biologist for the National Park Service visited the
Cerro Pelon overwintering site in Mexico (one of the "outlying sites")
and reported the following to Chip Taylor:
"While the reports of the high mortality at El Rosario and Sierra
Chinqua are certainly cause for grave concern, I wanted to let you
know that this extreme mortality event may not have affected all
overwintering sites. We saw no evidence of die-off, there was only
what I would consider "background mortality", evident in the relatively
small numbers of dead butterflies we saw on the ground."
Likewise Mark, subsequent visits to both the Herrada colony
(another "outlying colony") as well as Cerro Pelon by monarch biologist
Dr. Bill Calvert revealed no evidence of mass mortality.
Predictably, there was no media coverage of the fact that
there was alot LESS monarch mortality at the southern outlying colonies
where there was a LESS pristine forest!! Instead, in a Feb. 2000
press release the World Wildlife Fund reported:
http://www.worldwildlife.org/news/headline.cfm?newsid=327
"The forest canopy was too thin to protect the delicate monarchs from
the rain and cold weather last month," said Brower, the U.S.'s leading
monarch expert. "A healthy and intact forest serves both as an umbrella
and a blanket that protects the monarch colonies from the wind, rain and
cold."
Mark, something else occurred this winter in Mexico that
didn't receive media coverage and shatters the politically appealing belief
that an intact forest can protect the monarchs from mass mortality during
storms and freezes in Mexico.
At the time the storm hit in January, the El Rosario colony was split into
two subcolonies. One colony was formed in the usual location just above
some farmed fields and the other was formed further up the mountain, beyond
a ridge where tourists normally are not allowed to go. Monarch mortality
was much greater at the upper colony according to Chip Taylor.
Now the irony is that that just a few years ago Lincoln Brower had told us
ago that he considered the forest at this upper colony "more intact" than
the forest at lower colony next to the farmed fields.
Specifically, here's what Lincoln Brower told the NY Times reporter
in Sept. 2000 http://www.biotech-info.net/wintering_grounds.html
"Dr. Brower said that in one region where there has always been
a large monarch colony, development has encroached to the point
that the once remote roosts of monarchs are now dangling in trees
right next to farm fields. This winter, the butterflies startled
biologists by abandoning the site, moving over the mountains to a
more intact forest area -- an increasingly rare commodity -- that
they had never used before."
My point here Mark is that there was alot LESS mortality this winter
at the colony Dr. Brower described as "dangling in trees right next to
farm fields "than at the colony located further up the mountain in a more
intact forested area.
Predictably, there was also no media coverage of the fact more monarchs
died this past winter in the portion of the El Rosario reserve that scientist's
have told us has the most intact forest.
Paul Cherubini
Placerville, Calif.
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