Butterflies without borders: Monarchs
By Honey Sharp
On an early March day in 2010, I walked into a Gothic cathedral. Not a typical one, this one was in the High Sierra of Michoacán, Mexico. As if entering Chartres, my eyes were immediately drawn towards the heavens. The ceiling though was an indigo sky and the walls and buttresses were conifers. Best of all, living creatures — monarch butterflies in the tens of thousands— made for glorious stained-glass windows.
Here in El Rosario, a protected sanctuary near the town of Angangueo, these bright orange, black and white butterflies were clustered like hanging nests in the upper branches of the oyamel conifers. These butterflies without borders were preparing to embark on their long and arduous trip towards El Norte. We have all heard about the remarkable migrations the Eastern monarchs perform each year. They are the most famous migrating Lepidoptera known, traveling up to 3,000 miles in each direction and faithfully returning to the same over-wintering sites in the central Mexican highlands. This phenomenon, that includes a span of three to four generations in one year, has intrigued scientists and laymen for decades. Unfortunately, their voyages are getting tougher. The devastating drought on their migration paths in Texas and northern Mexico is having a deleterious effect on their survival rate. With little nectar from flowers and compromised sources of water, these migrants are being seriously challenged.
Notwithstanding the effects of climate change, other major factors are affecting their numbers: loss of habitat and food sources due to industrial agriculture. Beginning with roadside management practices involving herbicides and frequent mowing and ending with the worst of all culprits: Monsanto Round-Up Ready genetically engineered crops; the odds are stacked against them. Round-Up Ready is so selective, so “perfect,” that it was developed to ignore crops such as soybeans and corn, while killing the weeds, e.g. milkweed or Asclepias. Since monarchs lay their eggs upon this “weed” and their caterpillars rely upon it exclusively for food, much is at stake.
Experts like Dr. Chip Taylor, an insect ecologist and the director of Monarch Watch at the University of Kansas, are warning that the explosion in genetically modified crops is threatening monarchs by depriving them of their prime larval habitat and food resource. Milkweed also acts as a protector, infusing the monarchs with what to birds is a highly unpalatable taste—a typical miracle of nature. Indeed, other butterfly species such as the Queen and Viceroy evolved to visually mimic the monarch, thereby staving off potential predators.
As monarch numbers are decreasing, the integrity of Michoacán’s overwintering sites is now more important than ever. Unlike in the United States and Canada where monarchs are far more dispersed, the challenge in Mexico revolves around the monarchs’ dense number clustered in just a few small sites. This makes the possibility of habitat destruction here very serious. The five monarch sanctuaries, such as El Rosario, established in the 1980s by the Mexican government, are more important than ever. Unfortunately, the oyamel trees on which the Monarchs cluster remain valuable lumber sources that many local people depend upon for income. Although such logging is prohibited and ecotourism is promoted as an alternative, lumbering, at least for some, continues to be more lucrative.
Fortunately, conservation organizations, such as the Mexican group Monarca, A.C., continues to work with governmental agencies, NGOs and the local population to establish land protection, sponsor research, initiate education about monarch conservation, and in general enhance alternative economic development in the region.
Thus, while tourism does indeed provide economic support since the Michoacán people earn money for guided tours, transportation, food and souvenirs at roadside stands, serious environmental and economic challenges prevail.
For information about tours from San Miguel, go to: http://www.audubonmex.org/
Spaces are still available for March trips.
Honey Sharp, a landscape designer and writer on gardens and the environment, divides her time between San Miguel and the Berkshires, MA.