Mexico fires threaten Monarchs

Monarchs face a number of threats to their existence

Brush fires in central Mexico have destroyed hundreds of acres of forest, including part of a sanctuary for the "endangered" Monarch butterfly.

The blaze was thought to have been brought under control but, with fresh winds, it re-ignited and jumped firebreaks about 1.5km (one mile) away from the migratory butterfly's winter breeding ground, Mexico's Environment Secretariat said on Thursday.

Hundreds of firefighters have been battling the blaze, which started earlier this week after a campfire got out of control.

So far, the core area of the El Cacique reserve, 120km (75 miles) west of Mexico City, has not been damaged.

But about 750 acres (300 hectares) of brush and 75 acres of trees in a buffer zone around the main breeding ground have gone up in flames.

Habitat

Millions of Monarch butterflies fly each year from Canada and the United States to spend the winter months in the fir forests of west-central Mexico.

Tourists are also destroying habitat

The orange-and-black insects are not officially an endangered species.

But environmentalists have long been worried that destruction of their habitat by humans could endanger the Monarchs' summer and winter sites, thereby threatening them with extinction.

Threats to habitat include excessive logging in Mexico, and the use of pesticides in the US. Genetically-modified crops are another possible danger.

Increasing numbers of tourists flocking to view the spectacular Mexican breeding grounds are also taking their toll.

Fears

Scientists say the blaze will dry out the forest and thin the foliage canopy.

"The butterflies use the forest as an umbrella and a blanket," said Lincoln Brower, an American biologist who has studied the Monarchs for 45 years. "If they get wet, they lose their tolerance to freezing."

"The migration and overwintering biology could collapse completely in the eastern United States. As far as we know they don't know where else to go."

All Monarchs from east of the Rockies winter in Mexico in an area one millionth the size of their northern breeding grounds, Professor Brower said.