February 2018: Monarch Migration

A bright orange and black monarch butterfly with wings spread



The scientifically named Danaus plexippus, or better known as the Monarch butterfly, is one of the most recognizable butterfly species in North America. Unlike any other butterfly, the monarch is the only to make a two-way migration, making a journey to escape the uninhabitable winter climate and then returning for the fairer seasons (USDA Forest Service). This quest is required for the monarch, for unlike other insect species that can overwinter (live through the winter) as larvae, pupae, or even as adults, the monarch cannot withstand the cold winters of northern climates (USDA Forest Service).

Monarchs will fly up to 3,000 miles in the fall to reach their destinations, traveling anywhere from 50-100 miles per day (University of Minnesota Monarch Lab, 2016). It can take them up to two months complete their journeys. To aid them in the completion of their journey, monarchs will use air currents and thermals to effectively travel these long distances (USDA Forest Service). Monarchs of eastern North America will travel to the Sierra Madre Mountains of Mexico and monarchs of western North America will overwinter in southern California (USDA Forest Service).

Once there, they will cluster together, covering whole tree trunks and branches. As the winter ends, the monarchs will become more active and begin a 3-5 week period of intense mating (University of Minnesota Monarch Lab, 2016). While these monarchs will not make the trip back, the results of their mating (their children’s grandchildren specifically) will make the trip back up north once the climate is deemed acceptable (University of Minnesota Monarch Lab, 2016).

Despite their seemed buoyancy, the monarchs are in danger. Over the last 35 years, the population of western monarchs has dropped from about 10 million living along the west coast to approximately 300,000 (Brown, Crone, Pelton, Schultz, 2017). It is believed that a compilation of factors has caused this dramatic decline. These factors include: urban development, extended drought, and increased use of pesticides (Daley, 2017).

However, you can help! Milkweed and other wildflowers are essential to the monarch’s health (Pittman, 2016). Plant them in your garden to attract monarchs and help facilitate a home for them. If you don’t have a garden, reach out to your friends, family, neighbors, and local community to see what they can do to help. Also, refrain from using toxic pesticides in your yard. In addition, you can help support organic and nonGMO farmers by purchasing their goods as often as possible. The more these types of farms are supported, the more they will grow and help improve the lives of the monarchs.Common milkweed

For more information of how you can make your garden more butterfly friendly, consult the Morton Arboretum’s Plant Clinic!

In the Library

If you are interested in more information on monarchs, we have several resources in the library you may find useful: 

Four Wings and a Prayer: Caught in the Mystery of the Monarch Butterfly
The Monarch Butterfly
Monarch and Milkweed
Monarchs in a Changing World: Biology and Conservation of an Iconic Butterfly *
Mariposa Road: The First Butterfly Big Year *

We also have resources that can assist you in making your yard a monarch friendly environment:

Native Plants in the Home Landscape: For the Upper Midwest
Gardening with Native Plants
Gardening with Prairie Plants: How to Create Beautiful Native Landscapes
Grow Wild!: Low Maintenance, Sure Success, Distinctive, Gardening with Native Plants
A Native Plants Reader
Pollinator Friendly Gardening
Gardening for Butterflies : How You Can Attract and Protect Beautiful, Beneficial Insects
Butterfly Gardening with Native Plants: How to Attract and Identify Butterflies *

Don’t forget to take a look at ACORN, the Arboretum’s digital collections repository!

May T. Watts examining Milkweed pods
Vines: Overlooked Treasures at the Morton Arboretum

*Access the Library’s e-book collection by entering the number on the back of your Sterling Morton Library card.



University of Minnesota Monarch Lab. (2016). Retrieved December 19, 2017, from https://monarchlab.org/biology-and-research/biology-and-natural-history/....

Migration and Overwintering. (n.d.). Retrieved December 19, 2017, from https://www.fs.fed.us/wildflowers/pollinators/Monarch_Butterfly/migratio....

Pittman, A. (2016, October, 03). The Monarch Butterfly is in Danger of Extinction-Here’s What you Can Do to Help. Retrieved December 19, 2017 from http://onegreenplanet.org/environment/monarch-butterflies-is-in-danger-w....