One of nature’s most curious phenomena is the Monarch butterfly migration. Each fall, a very special group of Monarchs is born with the ability and purpose to live for up to six months so they can complete the migration south. Why is that so special? Well, the adult Monarch butterfly’s life span is typically only two to six weeks. It takes three to four successive generations to complete the migration back up north.
Another way you can help the Monarch population is by understanding and supporting their migration journey. Here’s a wee crash course on migration information:
Monarch butterflies fall into three distinct populations that follow different migration paths across the United States:
● In Southern Florida, the Monarch population does not migrate.
● The Monarch population west of the Rockies migrates each fall from Western Canada to the coast of California near San Diego and Santa Cruz to spend the winter.
● East of the Rocky Mountains, the Monarchs migrate in the fall by several different paths originating in central and Eastern Canada and the Northeastern United States.
All three populations’ migration paths merge over Central Texas, and the entire group continues its migration together to central Mexico, where they spend the winter in the mountains in Oyamel fir forests.
This incredible journey south is completed in just one generation.
The Monarch’s time of migration each year depends on the temperature outside and the length of the days, but goes roughly like this:
● August 18-30: The peak Monarch sightings at the 49th parallel coincide with the start of their journey south.
● November 10-22: The majority of the Monarch population is seen in overwintering locations.
● March: The first generation to migrate north begins, but they won’t arrive at their most northern destination until the fourth generation in late July or early August.
HOW TO SUPPORT THE MONARCH MIGRATION JOURNEY
Since their migration takes multiple generations, it is crucial that Monarch butterflies be able to complete their life cycle multiple times all over the United States. By using our tips to build a butterfly garden and ensuring abundant access to nectar and milkweed, you are supporting these amazing little migrators — no matter where you live!
Specific Monarch migration information and tracking based on milkweed habitats is actively mapped by The Western Monarch Milkweed Mapper Organization actively maps the Monarch migration based on sightings and milkweed habitats. You can help their cause by reporting sightings of Monarchs and milkweed.