Conservation Challenges
Examining Issues That Affect the Monarch Population
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Population at Record Low
Once each year, the monarch's population is measured at the overwintering sites in Mexico. This graph shows the size of the population since record-keeping began in 1994.

• The population hit a record low this year
• Numbers declined 59% from the previous winter
• The population is 20 times smaller than its high in 1997
• Scientists are alarmed by the clear downward trend

Challenges on Breeding Grounds
The monarch cycles through 3-5 generations during the breeding season. Only the final generation migrates to Mexico. Monarch caterpillars feed exclusively on milkweed. Historically, the U.S. corn belt has produced half of the monarchs that migrate to Mexico. However, milkweed habitat has been greatly reduced in the region due to:

• New agricultural practices
  • Milkweed is being eradicated from soybean and corn cropland by the increased use of herbicides on genetically modified, herbicide-tolerant crops.
  • More acerage is being planted in herbicide-tolerant corn to meet increased demands for biofuels. High corn prices push more land into production.
• Weather extremes
  • Drought and excessive heat on the breeding grounds in summer 2012 is sited as a key cause of the record-low population in Mexico the following winter, and reinforces concerns about the potential effect of climate change.

Challenges on Wintering Grounds
Monarchs migrate to a unique forest habitat in central Mexico. The butterflies depend on the forest microclimate to survive the winter. The entire population overwinters together in a very small region.

• Deforestation
  • illegal logging continues to threaten/deplete the monarch's forest and disrupt its delicate microclimate
• Ecotourism
  • high-volume, unregulated ecotourism threatens the integrity of the monarch's winter refuge
• Other socio-economic pressures
  • The needs of the people who live in the region must be balanced with the needs of the monarchs. Humans and monarchs have competing needs for food, water, shelter and space.
• Concentration of population
  • The fact that the monarchs concentrate in one place for the winter makes the entire population vulnerable to a single storm, drought, fire, or disease.

Challenges of Migration
Migration is inherently risky. Monarchs must find habitat to meet their needs every day of the journey. Like links in a chain, the loss of one habitat component could break the monarch's annual cycle.

Need for International Cooperation
People of separate countries and different languages must join together to solve these conservation challenges.

"The Monarch butterfly unites the three countries of North America in peace. It is an ambassador of peace which requires protected areas and ecosystems that are preserved through sustainable agricultural and forestry practices. Let us continue to work together to maintain a healthy and balanced ecosystem for all North America." President Jimmy Carter

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