A Puzzling Decline in Butterflies - San Francisco Chronicle 12/22/99
Paul Cherubini
cherubini at mindspring.com
Wed Dec 29 21:07:20 EST 1999
While monarch butterfly counts along the west coast were low this past
fall, along the Atlantic coast it was a much different story: (data
below was copied from Dick Walton's web site)
CAPE MAY POINT, ROAD CENSUS 1992-1999
(NEW JERSEY, USA)
The following table gives cumulative averages of monarchs observed per
hour at the end of each week in Sept and Oct. over the last 8 years:
Week 1992 1993 1994 1995 1996 1997 1998 1999
1 8 12 96 43 9 184 3 23
2 11 12 155 35 7 125 28 17
3 12 41 143 29 52 156 21 106
4 13 68 124 27 59 173 39 181
5 12 82 129 27 73 153 51 463
6 12 81 108 27 69 140 50 475
7 13 72 95 29 66 129 54 409
8 11 65 91 27 63 114 51 357
Totals:92 433 941 244 398 1174 297 2031
Clearly, the fall migration of 1999 along the Jersey coast was by
far the best observed in the past 8 years.
In my opinion, the data do not support the popular notion that
monarch numbers are being appreciably impacted by urban sprawl,
malathion spraying over New York City, roadside herbicide spraying,
genetically modified crops, logging in Mexico, commercial butterfly
releases, etc. etc. The cumulative impact (positive or negative) of
these human activites to date appears to be trivial.
Paul Cherubini. Placerville, CA
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