Monarch Butterflies’ Marathon Migration


The journey south takes two months – the butterflies travel up to 160 km (100 miles) per day.

It’s a journey that would have most of us reaching for our passports, but monarch butterflies cover 4,800 km (3,000 miles) on their annual flight from Canada to Mexico. The skies fill with millions of monarchs in the world’s longest insect migration.

Monarch butterflies can’t survive the cold Canadian winter, so they fly south to warmer climes. Most monarchs live for a maximum of eight weeks, but the generation that hatches at the end of the Canadian summer is different. Instead of mating and dying, they put all their energy into the migration, and can live for up to eight months. After spending the winter in Mexico, the migrating generation reproduce and their offspring make the journey back to Canada.

Supporting the Species

Monarch butterflies only lay their eggs on milkweed plants because they are the sole food of the newly hatched larvae. However, herbicide use has decreased the number of milkweed plants in North America. Conservationists are encouraging people to plant milkweeds at home, to create the habitat the monarchs need to survive.