As autumn begins to seep through our windows, and set the trees ablaze, summer’s most beloved allurement retires from our New England home and returns south to their Mexican overwintering site. 

Butterflies of many kind embark on this jaw-dropping migration in autumn. Leaving their homes of North America and Canada on their 3000 mile journey to their winter destinations in southwestern Mexico to Sierra Chincua.(This map shows the route the butterflies will travel) Where the cool mountain ranges slow their metabolism.

They dangle from the branches of the Oyamel Fir trees. Providing a blanket like affect, keeping the temperatures from fluctuating.    

Unlike birds-who also migrate to warmer climates-these butterflies will never arrive back home. Once they reach their destination they spend months in a state called diapause, which is a hormonally-controlled state of dormancy that allows the butterflies to survive the winter. 

Weeks before the warmer and longer days, they are roused out of diapause by an internal timer, so they can reproduce and migrate back to their northern homes to warmer climates like Texas- away from their mountain accommodations- where they will mate and lay eggs. 

After a couple of days those same eggs will hatch into striped caterpillars of black, gold, and white. In two weeks, these caterpillars will consume enormous amounts of milkweed. 

Monarch caterpillars need large amounts of milkweed to survive. It provides nourishment, and is the only plant this type of caterpillar will eat, without it they cannot transform into their beautiful butterfly selves. 

After they hatch out of their chrysalis’ they start their journey, like the generation before them. After a few hundred miles this group finds a patch of milkweed and the process is repeated. 

It’s not known why they migrate, or how they know how to. But it could take up to 5 generations of butterflies to reach their homes in the North. 

So when the time comes, try to take a moment to watch this marvelous spectacle.