http://www.boston.com/dailynews/302/world/Monarch_butterflies_begin_arri:.shtml

Monarch butterflies begin arriving in Mexico, after migration from U.S., Canada

By Associated Press, 10/29/2001 20:35

MEXICO CITY (AP) The first arrivals in the annual migration of millions of Monarch butterflies from the United States and Canada began dipping and swooping into mountains of central Mexico Monday.

The fir forests of the central state of Michoacan are the wintering ground for the beautiful orange and black creatures, whose number here is expected to grow to more than 20 million by December, the government news agency Notimex reported.

The forest sanctuaries of the butterflies are to be opened to tourists on Nov. 7. The butterflies leave again in February and March to return to the north.

Each year, in a migration that can cover 3,000 miles, successive generations of butterflies from the United States and Canada fly to the same place in Mexico, a process scientists do not yet fully understand.

-- Anonymous, October 30, 2001