Groups File UNESCO Petition to Save Monarch World Heritage Site in Mexico

WASHINGTON (April 13, 2015)--The monarch butterfly refuge in Mexico, a UNESCO World Heritage Site that is winter home to tens of millions of migrating monarchs, should be declared “in danger” because the remarkable transcontinental migration it was established to protect “is at risk of disappearing,” a group of Mexican, American and Canadian civil society and conservation organizations said in a petition today.

The organizations jointly filed the petition with UNESCO (United Nations Educational, Scientific and Cultural Organization) seeking “urgent action needed to protect one of the world’s most spectacular and mysterious migrations.”  The petition was filed as officials from Mexico, the United States and Canada convene a wildlife conservation meeting in San Diego that will consider the crisis of the monarchs, which travel through the three countries and whose population has plummeted in recent years.

Scientists say massive herbicide use in the U.S. and Canada is wiping out the native milkweed plants that monarchs need to survive. The petition was filed by Mexican organizations Grupo de los Cien, Alternare A.C., Danaidas Conservación y Desarrollo Sustentable A.C., Telar Social México, and CostaSalvaje, the U.S.-based Natural Resources Defense Council, and the David Suzuki Foundation in Canada. 

“Mexico has made great strides in protecting the monarch reserve itself from illegal logging and other threats, but we can’t save the monarch migration without more help from the United States and Canada,” said Homero Aridjis, president of Grupo de los Cien and a former Mexican ambassador to UNESCO who was instrumental in the agency’s designation of the Monarch Butterfly Biosphere Reserve as a World Heritage Site in 2008.

“We’re hoping that international recognition of the monarchs’ peril will encourage stronger efforts by the U.S. to protect monarchs’ habitat and to bring back some of the milkweed that has been destroyed,” said Carolina Herrera, an international advocate for NRDC, which has filed a petition and two lawsuits against the U.S. Environmental Protection Agency seeking restrictions on glyphosate, the weed-killer that is the chief culprit in the monarchs’ decline. NRDC is also promoting programs to plant more milkweed.

“We've lost almost a billion monarch butterflies in the past two decades, and the migration to Canada is in serious jeopardy," said the David Suzuki Foundation's Rachel Plotkin. "It's time for all three countries to get serious about curbing herbicide use and planting butterfly-friendly corridors across North America.”


As recently as 1997, one billion monarchs overwintered at the isolated reserve after completing an annual 2,500 mile, multigenerational journey from Mexico through the United States to Canada and back, a phenomenon scientists still don’t fully understand. Virtually all the monarchs migrating through the Midwest and eastern U.S. converge in the late fall on the reserve in the mountains 62 miles northwest of Mexico City, where they huddle in dense clusters that weigh down the tree branches.  (A separate west-of-the-Rockies population overwinters in California.)

Climate change, drought and deforestation in Mexico may all have contributed to the monarchs’ decline.  But scientists say the main cause is the skyrocketing use of glyphosate (originally marketed as Roundup), following the adoption of genetically modified glyphosate-resistant corn and soybeans. This has wiped out much of the native milkweed where monarchs lay their eggs and is the only food their larvae will eat.  As a result, monarch populations have plunged: In January, only 56.5 million were counted at the reserve; the second lowest figure ever.

Such a small population is so vulnerable to further milkweed loss, drought, severe storms and other extreme weather that the migration -- which the Biosphere Reserve was established to protect -- “is at risk of disappearing,” the petition says. “Conservation action across the entire migration route is critical.” 

The petition asks UNESCO to put the reserve on the “List of World Heritage in Danger.” It also asks the World Heritage Committee to encourage steps by the U.S. and Canada to protect the monarchs’ milkweed breeding habitat by limiting glyphosate use, to promote programs to restore milkweed, and to study other ways to save the butterfly migration.

As parties to the World Heritage Convention, the United States and Canada have committed to help protect such natural World Heritage sites and not to take measures that might directly or indirectly damage sites located in other countries.  The UNESCO World Heritage Committee cannot force a country to act, but it can marshal international attention to the Heritage sites and recommend “corrective measures” to ensure the conservation of a site. The World Heritage Committee will now examine available information and may send experts to assess the situation and threats to the site.

In San Diego, the annual meeting of the Trilateral Committee for Wildlife and Ecosystem Conservation and Management (not part of the U.N. system) opens today and has scheduled a plenary session for Wednesday on Monarch Butterfly Conservation.

A copy of the UNESCO petition can be found here:

For more detail about this issue, read NRDC Latin America Advocate Carolina Herrera’s blog:


Related Press Releases