MEXICO CITY — Satellite images show illegal loggers have clear-cut large swathes of trees in the heart of a monarch butterfly reserve in Mexico, threatening the entire population with extinction, according to a leading researcher.
The images show illegal loggers felled 1,100 acres of trees since 2004 in the core of a wooded park in Michoacan state where clouds of orange- and black-winged butterflies nest each winter, said Lincoln Brower, a professor emeritus of biology at Sweet Briar College in Virginia, who has studied the monarchs for 52 years.
"The butterfly area can't survive if this kind of logging continues," said Brower, who also directs the preservation group that paid for the commercial satellite images, which were published by NASA online. He noted that the delicate creatures need leafy foliage to protect them from rain and cold.
The core area is known as the Lomas de Aparicio, which had been largely intact up through 1986.
A Mexican presidential decree issued in November 2000, forbids logging in the central zone of the Monarch Butterfly Biosphere Reserve, a 124,000-acre area that spans Michoacan and Mexico states. However, regulation has been spotty.
Mexico's environmental protection agency did not return several phone messages seeking comment Monday.
The disappearing habitat threatens a delicate migratory route that has spanned two continents and a million square miles for some 10,000 years, Brower said.
Each September, the butterflies begin a 3,400-mile journey from the forests of eastern Canada and parts of the U.S. to the central Mexican mountains. The voyage is considered a scientific wonder.
In a statement describing the satellite images, NASA said that "based upon the degradation apparent in these images, it is unlikely monarchs will form overwintering colonies at this Lomas de Aparicio site in future years. If they do return, they will be subject to much greater environmental risks during their six-month overwintering stay."
"The researchers are greatly concerned that the entire monarch butterfly migration and overwintering phenomenon in eastern North America may collapse in the near future if the Mexican government does not fully enforce the logging ban," NASA added.
The Associated Press contributed to this report.