Originally published on Thu March 14, 2013 12:47 pm
Monarch butterflies that once covered 50 square acres of forest during their summer layover in central Mexico now occupy fewer than 3 acres, according to the latest census.
The numbers of the orange-and-black butterflies have crashed in the two decades since scientists began making a rough count of them, according to Mexico's National Commission of Natural Protected Areas.
At a news conference Wednesday, the commission said the count was down 59 percent from December 2011 levels, when the insects filled 7.14 acres of fir trees in central Mexico.
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