Number of migrant Monarch butterflies trebles in Mexican sanctuaries

Millions of Monarch butterflies that annually migrate to Mexico from Canada and the United States are occupying four hectares of forest in Mexico, three times more than in 2014.

Experts have been looking for an increase in the number of migrant Monarch butterflies during the hibernation season since 2014, when their registered occupied space was at its lowest.

The butterflies are resting in six Mexican sanctuaries in the central and western parts of the country.

Mexico's National Commissioner of Protected Natural Areas Alejandro Del Mazo said the country aims to have 225 million migrant butterflies by 2020, occupying six hectares of the pine and sacred fir tree forests.

"It is very good news but obviously we have to continue working to reach the goal for 2020," said Del Mazo at a news conference.

"This season has been memorable in terms of visitors. We have had over 200,000 visitors in the six sanctuaries," added Del Mazo.

Each autumn, millions of Monarch butterflies, which weigh less than one gram each, travel over 4,000 km from east Canada and United States to escape from the cold and hibernate in Mexico. The butterflies enter the country through the northern state of Coahuila.

The north American nations formed a high-level working group to conserve the Monarch's migration in 2014 after a marked decline in the number of migrant butterflies since 2011. Endi