Amazing Monarchs in Mexico: A Tale of Death and Survival
While vacationing in Mexico this March, alarming headlines caught my attention. “Massacre of the Monarchs,” screamed the English-language News. “At Least Five Million Monarch Butterflies Dead,” informed El Informador.
While the cause of the massacre is still uncertain, the tragedy of the event saddened many who have visited the amazing monarchs in their overwintering sites in Mexico’s Sierra Madre Mountains. A year ago, I was one of the pilgrims.
With the Dicksons, my foreign service friends, we drove from Mexico City to Valle de Bravo, a wooded valley in the mountains, about 100 miles west of the capital. Annie, who had just completed a seventh-grade project on the monarch butterflies, informed us on the characteristics of this long-distance champion.
Each year, the orange, black and white insects migrate from southern Canada and the United States at the end of summer, often travelling two thousand miles, Annie explained. The monarchs west of the Rocky Mountains—only five percent of the total butterfly population--travel to Southern California; their relatives east of the Rockies fly to Mexico and settle in the forests of the states of Michoacan and Mexico. Their journey takes about three months. While monarchs feed exclusively on milkweed growing up, they sip nectar from flowering weeds as they fly south. In the forests of the Sierra Madre, nearly two miles above sea level, they find what they need for the winter months: cool temperatures, high humidity, and a thick canopy that protects them from wind, snow and rain.
The monarchs’ life span is eight months, and some of the creatures we were about to see might make it all the way back to Canada, Annie concluded, as we drove into the parking lot at Valle de Bravo. Campesinos with donkeys and horses awaited us. One look at the steep incline of the hill leading to the sanctuary made me opt to climb on the back of a donkey, with a barefoot ten-year-old as my guide. My friends decided to walk and soon disappeared in the cloud of dust we left behind.
Within 20 minutes we had reached the thick of the forest. It took a while to get used to the dark as I proceeded on foot. Slowly I realized that the enormous bags hanging from branches, and the black-beige mass of folded wings lining the trees were sleeping butterflies. Occasionally, a monarch spreading its flaming orange wings would fly by--perhaps looking for water or a cozier neighborhood.
About a dozen awed tourists crept through the thick underbrush, mindful not to step on slumbering monarchs covering the ground. We tried to take it all in and Annie’s older sister Margaret flashed her camera for close-ups, following her mother’s whispered advice. We couldn’t help exclaiming at the wonder of the sight, but park rangers motioned for us to hush our voices. This was, after all, a sanctuary, deserving the quiet and respect we usually accord sacred sites.
Millions of the fragile and light monarchs were roosting noiselessly and without damage to the environment. Their sleep seemed to wrap them deeply into the mystery of their genetic destiny. About 100 million have come to Mexico for thousands of years, arriving in November, leaving at the end of March. On their way back, the females lay more than 400 eggs on milkweeds, one egg and leaf at a time, and then they die.
But how do they find their way without map or compass? we wondered. This is their only trip, yet year after year they find their way from freezing temperatures in Canada and the United States to the warmer forests of Mexico’s highlands, just like their ancestors did. Some scientists think monarchs have a genetic memory, others think they travel by solar navigation—no one is certain what guides their flight.
It is certain, though, that the monarchs’ safe wintering sites in California and Mexico are threatened by logging and human development needs. In Mexico, the government has created vast reserves of land that is communally owned by peasant families who have not been adequately compensated for logging restrictions imposed by decree. Yet, the peasants depend on logging for their own survival, and clearings have been cut into the thick canopy, despite the prohibition. The clearings are like holes in a winter coat, experts explain. The openings let in the snow and freezing rain that destroy the vulnerable monarchs.
Several U.S.-based environmental groups have worked in partnership with the Mexican government and local communities to halt the loss of monarch habitats. They raise funds for compensation, and monitor the butterflies’ wellbeing. When the March massacre was first reported, David Marriott of the non-profit Monarch Watch was immediately on the scene and filed this report:
On the night of March 2 “there was a fierce storm that hit the mountains near Valle de Bravo and Capulin. Very strong winds… with snow and ice destroyed many homes and trees..… I have never seen anything like it. It looked like a total disaster zone. Snow and ice levels reached 8,000 feet.”
Approximately five to seven million monarchs were found dead. There was an immediate suspicion that angry loggers had killed the butterflies with pesticides. But a report from the World Wildlife Federation (WWF) cautioned against hasty conclusions:
“Most of the butterflies have large reserves of fat in their bodies, and after they are killed, the fat gradually leaks out into their wings. As a result, their wings become saturated with fat and have a dark greasy appearance. This could lead in experienced observers to the false conclusion that they had been killed by spraying… They could have died of natural causes,” said the WWF.
Most likely, the monarchs were killed by the cold, and observers point out that a similar ice storm five years ago also killed millions of butterflies. Still, clandestine logging may be the ultimate culprit in the story, because gaps in the forest’s thick canopy let in the killer winds.
Whatever the cause of their dying, the amazing and delicate monarchs have become a powerful symbol for the fragile nature of our ecosystem. Their needs for survival often seem to collide with human needs and greed in a world of ever-decreasing resources. The March massacre was a reminder that a solution has to be found for people and butterflies to co-exist in a long-term sustainable manner, including the wooded hills of Valle de Bravo.