Survey shows 69% increase in area occupied by monarch butterflies

Mexico City, January 27, 2015 – A new survey of migratory monarch butterflies at their wintering habitat shows a 69% increase in the area they occupied this winter compared to the same period last year. Yet even with the increase, this is still the second smallest area occupied by these butterflies in Mexican sanctuaries since 1993, highlighting the urgent need for better monarch protection. 

Monarch butterflies (Danaus plexippus) migrate up to 4,500km from Canada and the United States to establish their colonies in temperate forests in Mexico. The forest area occupied by these colonies serves as an indirect indicator of the number of butterflies that make the long journey each year.

The study was carried out by the WWF-Telcel Alliance and Mexico’s National Commission of Protected Natural Areas, and involved biweekly trips to colonies with a historic presence of butterflies. In total, nine monarch butterfly colonies were recorded, both inside and outside of Mexico’s Monarch Butterfly Reserve.

“The 2.79 acres occupied by monarchs this winter should serve as additional motivation for the leaders of Canada, Mexico, and the United States to translate the commitment they made in Mexico in February 2014, to concrete and immediate actions,” said Omar Vidal, Director General of World Wildlife Fund in Mexico. “It is crucial that we restore and protect the habitat of this iconic species in all three countries, but above all that we limit the use of herbicide and land conversion in the United States and maintain efforts to avoid deforestation in Mexico,” he added. 

Protecting monarchs and their habitats

Across their migratory route, monarch butterflies face many threats to their survival. In Canada and the US, a loss in breeding habitat is linked to a decrease of milkweed—the main food source for monarch larvae—due to herbicide use and land conversion. In Mexico, monarch hibernation sites are threatened by illegal logging. And extreme climate conditions in Canada, the US and Mexico all contribute to the dramatic decrease in monarch butterflies that hibernate in Mexico.

Though much must still be done, coordinated efforts in the core zone of the Monarch Butterfly Reserve are making a difference. Deforestation and forest degradation due to illegal logging in the core zone of the Monarch Reserve drastically decreased thanks to the commitment made by the ejidos and indigenous communities of the Reserve, the surveillance efforts and funding for environmental services from Mexican authorities, and the support of philanthropists and Mexican and International companies such as Telcel, the Carlos Slim Foundation and the Yves Rocher Foundation of France, which promote sustainable projects for residents.

Download the full report here.

For more information contact

Rebecca Spring, WWF-Canada, +1 416 489 4567 ext 7343, [email protected]