Monarch Butterfly Migration

Every fall, millions of monarch butterflies travel up to 3,000 miles from Canada and the United States to the mountains of central Mexico. It is one of the longest insect migrations in the world. The butterflies spend the winter in Mexico, then fly north again in the spring. This amazing journey takes several generations to complete.

An Incredible Journey

Monarch butterflies born in late summer are special. They live much longer than other monarchs and can fly thousands of miles south. They navigate using the sun and Earth's magnetic field. Millions of monarchs cluster together on trees in the mountains of Mexico to stay warm through the winter.

Monarchs in Trouble

Monarch butterfly numbers have dropped sharply in recent years. The main problem is the loss of milkweed, the only plant where monarchs lay their eggs. Pesticides, habitat loss, and climate change also threaten them. People can help by planting milkweed in their gardens and avoiding pesticides on their lawns.

Fun Facts

• A single monarch butterfly weighs less than a paperclip but can fly 3,000 miles!
• Monarchs that migrate to Mexico have never been there before, yet they find the exact same trees their ancestors used.
• The monarch butterfly population in Mexico is measured by how many acres of trees they cover.

Did You Know?

It takes three to four generations of monarchs to complete the full round trip migration from Mexico to Canada and back!