Monarch butterflies in Valle de Bravo Mexico

The Monarch is the world's only migrating butterfly. Each year tens of millions of these fragile insects make a round-trip journey across North America to Mexico and back. Now a group of humans have embarked on a bold mission to track the Monarch's migration and help protect the insect and its habitat.

On a soccer field near downtown Washington, Francisco Gutierrez is working with his crew to assemble his ultralight aircraft. The veteran pilot has painted the wings black and gold -- just like a monarch butterfly's.

"It's exactly the same as a hang glider," he says. "You can see now they are putting down the wing and then we put in a unit with the engine that can carry two people - pilot and passenger. This light aircraft is like a butterfly for us. We are like monarchs and sharing the weather with them. So they don't fly. We don't fly."

Pilot Francisco Gutierrez and the Papalotzin, photo courtesy World Wildlife Fund

Francisco Gutierrez and a team of co-pilots from Canada, the United States and Mexico are flying the migration route of the Monarch. Their journey in the Papalotzin - which means little butterfly in the ancient Aztec language - began in August in Canada and ends in November in Valle de Bravo, Mexico, where Monarchs hibernate in winter.

"It is amazing that this incredible insect that weighs less than one gram flies 5,500 kilometers each year with no problem," Mr. Gutierrez says. He adds, "Not one, but millions of Monarchs from North America go to this place that is just an area of a few square miles."

Lincoln Brower

Monarch expert Lincoln Brower from Sweet Briar College is on hand to welcome the pilots and crew to Washington, one of more than a dozen stops they'll make between Canada and Mexico. He says the Monarch's realm is a three-country phenomenon. "The monarch migration is dependent upon what happens in Canada, the U.S. and Mexico, and particularly in the U.S.," he says, "because the Monarchs lay their eggs only on milkweed plants. The caterpillars can't eat anything else. And the females never make a mistake. They only lay on milkweeds."

By November tens of millions of monarchs born in the United States and Canada will converge on the high elevation fir and pine forests of central Mexico.

Carlos Galindo-Leal is forest coordinator for World Wildlife Fund, a co-sponsor of the tracking mission. He says despite a reserve established to protect Monarch habitat, illegal logging continues to destroy valuable forestland.

He says the successful efforts to halt this practice reach beyond the Monarch to the ecology of the region. "The Monarch is only one species. It is an important species, but these forests have a lot of unique species,"

Carlos Galindo-Leal, photo courtesy World Wildlife Fund

Mr. Galindo-Leal says. "These are really tall mountains. The monarch is basically sitting at 3,000 meters and up there are species endemic to the mountains - salamanders, birds and a number of species. No only do we protect these species, but the water - about 30% of the water that is there goes to the main cities including Mexico City." So protecting the Monarch butterfly's habitat he says, improves the lives of people as well.

Monarch expert Lincoln Brower says a sustainable environment requires balance between human and economic uses of the land.

"You just can't keep extracting," he says. "You are going to destroy the biodiversity on vast areas of this planet."

The pilots and crew tracking the Monarch migration route share Mr. Brower's passion for the insect. The team - which is producing a movie about their journey - is also writing a daily web log  that details their progress and invites you along for a virtual ride with the Monarch butterflies.