Why Do Monarchs Migrate?
As fall approaches, so does monarch migration season. Read on to learn about this fascinating behavior, and what causes these beautiful creatures to fly thousands of miles each year.
The monarch butterfly is the only insect to make a two way migratory path. Just like birds, they fly south in search of warmer climates. Every year monarchs will fly up to 3000 miles to reach their wintering grounds.
Why do they make this long journey? To survive. North American monarchs are not able to survive the winter climates of the upper regions of their homeland, so they migrate south and west each autumn to escape the cold weather. The monarch migration usually starts in about October of each year, but can start earlier if the weather turns cold sooner than that.
If the monarch lives in the Eastern states, typically east of the Rocky Mountains, it will migrate to Mexico and hibernate in specific trees called oyamel firs. If the butterfly lives west of the Rocky Mountains, then it will hibernate in or around Pacific Grove, California in eucalyptus trees.
What's even more interesting is that monarch butterflies will use the same trees every year, despite the fact that every year, a whole new generation of monarchs make the journey.
There's another reason these butterflies make their yearly trek. Their wintering grounds do not have the food their larvae need to flourish. Monarch larvae dine exclusively on milkweed. Thus, they need to fly back north to where the plants are plentiful.