Deforestation in the wintering grounds of the Monarch butterfly in central Mexico has dropped to just over one acre's worth of trees, compared to the hundreds of acres lost annually in the past, experts said Thursday.
And fewer of the pine and fir trees that shelter the butterflies have been lost to bad weather this year, according to a report by researchers from Mexico's National Autonomous University and the Monarch Fund.
Illegal logging in the protected butterfly reserve dropped from 1.56 hectares in the 2009 winter season to just under a half hectare (about one acre) in the reserve's core zone during this year's winter.
"This is what happens when you have enforcement of the law, and economic alternatives for the inhabitants," said Omar Vidal, whose environmental group, the Worldwide Fund for Nature, has contributed along with cellphone company Telcel to economic development projects like tree nurseries in the reserve.
Mexican federal and state police forces have also cracked down on illegal logging in the 13,550-hectare (33,482-acre) reserve and in a larger buffer zone around the park where logging is also prohibited.
The reserve is inhabited by communities of small farmers who once looked upon logging as a way to supplement their incomes.
At its peak in 2005, logging devastated as many as 461 hectares (1,140 acres) annually.
Turning to weather, the report said 2.68 hectares (6.6 acres) of trees in the reserve were lost to drought this year, compared to 177 hectares (437 acres) lost mainly to floods and landslides in the previous winter.
The findings follow a study showing a recovery in the number of the orange-and-black Monarch butterflies that visit Mexico in a little-understood annual migration.
The winter of 2009 saw a 75 percent drop in the number of butterflies, perhaps as a result of drought or other climatic conditions. But this year's winter saw a total of 9.9 acres (4 hectares) of butterfly colonies, more than double last year's 4.7 acres (1.9 hectares), the lowest level since comparable record-keeping began in 1993.
Butterflies in the reserve huddle so closely together on tree boughs _ apparently for warmth _ that experts count them by the amount of area the clumps cover.
While the recovery is encouraging, droughts are again affecting some portions of the United States where the butterflies have migration paths or spend the summer.
Vidal said Mexico must keep its guard up against logging in the reserve, located in the mountains west of Mexico City.
"Half a hectare looks like very little, but it should be zero," Vidal said.