MEXICO CITY -- Dozens of writers, scientists and activists have signed an open letter to the presidents of the United States, Mexico and Canada warning that logging and mining threaten the reserve where monarch butterflies winter in the mountains west of Mexico City.
The letter by Mexico's Group of 100 warns that plans to revive an old gold and silver mine threatens water supplies in the reserve.
The head of the group also warned that small-scale illegal logging has increased in the wake of the butterflies' annual departure for the U.S. and Canada, where they breed.
Homero Aridjis said Wednesday that authorities must implement tight, year-round security to prevent logging, not just when monarchs are present.
The monarchs have made a big comeback after suffering serious declines, but remain far below historic levels.
