By Carmen Roberts
Illegal logging in Mexico's national parks continues to threaten millions of butterflies, despite a government crackdown, environmentalists warn.
Monarch butterfly numbers have been brought low
Mexico's government has taken drastic measures to protect the butterflies.
It has formed a team of 17 park rangers, armed with assault rifles and body armour, to protect the colonies of monarch butterflies in Michoacan state.
In 2004, numbers of the migrating monarch butterflies plummeted to 100 million - the lowest ever recorded.
The park rangers are there to help protect the winter nesting grounds of tens of millions of orange and black winged butterflies from armed gangs of illegal loggers in the 56,259-hectare Monarch Butterfly Biosphere Reserve.
Despite facing hefty jail sentences, the loggers have continued unabated, say environmentalists.
"The illegal logging has actually accelerated in the last four to five years," said Professor Lincoln Brower, a biologist and leading expert on the monarch butterfly.
After several flights over the area, Professor Brower says he is angered at the vast empty zones, clearly visible from the air.
"I'm just appalled by the failure of the local authorities and the federal government to cooperate to put these illegal loggers out of business," he said.
In a country where kidnappings and car-jackings are run of the mill, the illegal timber trade is equally ruthless. Gangs are frequently armed and work at night to avoid detection.
Illegal logging continues despite a crackdown, scientists say
Mexico's environment ministry estimates the country's highland fir forests have shrunk by half since 1968, despite massive planting operations.
In 2004, butterfly numbers plummeted to around 100 million, the lowest ever recorded. The conservation group WWF says numbers have tripled this season, but are still no where near the level - possibly 10 times this - seen in the mid 1990s.
Logging has been the main source of income for many generations, and while some communities have turned their hand to 'butterfly tourism', many others feel cheated.
"The environmentalists have pushed the government, but... we have no other way of making a living," said Homero Gomez, spokesperson for Rosario, a village which is host to the most monarchs and tourists each year.
But Jose Alvarez - head of the Michoacan Reforestation Fund, a group that has helped villagers plant more than 480,000 trees this year alone - says this is a near-sighted argument.
"If this (logging) continues, we won't have any butterflies, there won't be any water and there won't be any villages; the trees are the basis for everything that is living in this area," he said.
The Michoacan Reforestation Fund is working closely with Professor Brower and scientists from the US space agency (Nasa) on an aerial reconnaissance programme to try to understand which parts of the forest are critical for the monarchs, and where those areas are in relation to the trends in logging activity.
Professor Brower says these recent reconnaissance flights have confirmed what has baffled scientists for years: the monarch butterflies have been journeying 5,000km from Canada and the US, and returning to exactly the same over-wintering sites in Mexico for the past 25 years.
He says international pressure is needed to help save not only the butterflies but the entire ecosystem.
The monarch has become a symbol of cross-border co-operation with the US, but some scientists fear it could become a symbol of a common failure to protect the environment.