The monarch butterfly hits the peak of its winter migration in October, and as it makes its way from Canada and the U.S. to Mexico, all three countries will be watching its numbers closely. In February, President Enrique Peña Nieto of Mexico, flanked by President Barack Obama and Prime Minister Stephen Harper of Canada, announced that they would set up a task force charged with saving the continent's monarchs. Then in late May, the three countries devoted several sessions to the butterfly at an annual wildlife conservation summit. That is because the monarch is declining precipitously. In the past decade the population east of the Rocky Mountains dropped from an estimated one billion to the 33 million that survived their journey last winter; the western population, which winters in California, has also dwindled in recent years.
“We are on the verge of losing one of the most magical animal migrations,” says Dan Ashe, director of the U.S. Fish and Wildlife Service. Much of the monarch butterfly's life is spent migrating, a journey that for some individuals can cover more than 3,000 miles.
Once called the “Bambi” of the insect world, the monarch is the most recognized butterfly in North America, but its popularity alone will not save it. Researchers and wildlife officials say it will take a combination of approaches to ensure a healthy population. Task force members are now collaborating on a conservation plan that they hope will reverse the drastic decline. And each country has an important role.
Loss of one billion milkweed stems in the summer breeding range because of converted grasslands and herbicides. Monarch larvae eat milkweed exclusively.
Extreme weather, including colder winters in central Mexico and droughts in Texas.
Invasive flora on which monarchs lay eggs. The hatched larvae are unable to survive there.
Increasing scarcity of nectar plants along migration routes.
The Mexican government has already combated large-scale illegal deforestation in the Monarch Butterfly Biosphere Reserve, a 140,000-acre forested area in central Mexico, where eastern monarchs arrive starting in November and remain until March. But officials are still working on strengthening sustainable forest practices within groups living on ejidos, or small protected, communal lands. Suggested alternatives include ecotourism and mushroom cultivation.
Creating more milkweed habitat is paramount, according to fws director Ashe. The most direct option is to build “living roadways” of milkweed beside highways such as Interstate 25 and Interstate 35, which run through the central U.S. Another task force objective is to support the Conservation Reserve Program, which protects private farmlands as native environmentally sensitive lands. Those farmlands could sustain milkweed as well as native nectar plants.
Fewer monarch offspring are returning in the spring to Canada, where some lay their eggs. The Canadian government is exploring setting aside funds for breeding habitat creation on farmlands, roadsides and utility corridors. Canada currently protects parts of the monarch's staging habitat, where the butterflies congregate as they prepare to migrate south, but larger areas are needed.