MEXICO CITY — A recent crackdown on illegal logging has not slowed deforestation threatening the winter refuge for monarch butterflies, according to a scientist who has been studying the insects for 50 years. In an effort to protect hundreds of millions of monarch butterflies that migrate to Mexico from the eastern United States and Canada each fall, police and environmental prosecutors in November closed down illegal sawmills, arrested 28 people, and confiscated illegally harvested lumber in central Mexico. "In my opinion the Mexican law enforcement effort to protect these butterflies is not effective," said Lincoln Brower, an ecologist who may be the foremost expert on the 3,000-mile (4,800-kilometer) monarch migration to Mexico.
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Brower said when he flew over legally protected butterfly areas this month, he saw working logging trucks, suggesting that illegal timbering continues to encroach on highland fir forests that are essential to the monarchs' survival. "You can go up in a 20-minute flight and see what's going on," he said. "It's obvious that there is massive deforestation on a grand scale. It is obvious from talking with local people that they are scared and angry because these (loggers) are analogous to the mafia in the way they treat the law and the land."
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The monarch butterflies return each year to carpet fir trees in Michoacan and neighboring Mexico state, an aesthetic and scientific wonder that attracts about 200,000 visitors annually. The butterflies represent a seasonal economic boon to the landowners, known as ejiditarios, who manage four main butterfly sanctuaries in the 56,000-hectare (138,380-acre) Monarch Butterfly Biosphere.
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During a four-month stay in Mexico, monarch butterflies remain susceptible to the wet and cold. Even small holes in a forest canopy can expose butterfly colonies, each containing millions of insects, to the fatal chill of a clear winter night, Brower said. "If the canopy is closed, it's like a blanket," Brower said. "It's really important that the forest be intact all the way down the valley.... It's a very limited system that the monarchs are capable of living in, as far as anybody knows."
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http://www.enn.com/news/2004-01-28/s_12477.asp