The Habits of Monarch Butterflies and Their Far Flights

view of Monterrey Bay off the cliffs of Wilder Ranch State Park

Walking the California Coastal Trail

Starting at Wilder Ranch State Park you can pick up one of the many sections of the California Coastal Trail (CCT). Wandering the coast we noticed a number of monarch butterflies accompanying us on our walk. Exploring the buildings and gardens at Wilder Ranch itself, brought us to a large group of butterflies resting behind the historic adobe. This was a reminder that it is once again butterfly season in California.

monarch butterfly hanging from a twig

Monarch Migration

November and December are the peak times to spot Monarch butterflies (Danaus plexippus) on their migration path. Every year they travel south for the winter beginning in late spring and summer from Canada and the Pacific Northwest. The butterflies divide at the Rocky Mountains into eastern and western groups. The western group spends the winter in California, and the eastern group winters in Mexico, more than 2,500 miles from where they started. At the end of winter, the males have died and the females head back north. Each butterfly lasts only a couple hundred of miles. They then lay their eggs on milkweed and die. The trip back takes four generations of adult butterflies. The monarch that returns to Mexico or California the following year has never been there before.

over a dozen monarch butterflies roosting off a leafy twig

Monarchs Roosting

California is the only place in the United States with large gatherings of monarchs. Monarch butterflies spend the winter in more than 200 forested groves along the California coast ranging from Los Angeles to Monterey. They rest in trees (primarily eucalyptus and pine) in large groups to stay warm and to protect them from the elements and predators. Just a short day trip away to Natural Bridges State Beach will bring you to a large roosting group.

Much of the monarch's natural habitat is threatened due to urban development and widespread use of herbicides. The monarch caterpillars can only eat milkweed (Asclepias) leaves. Milkweed is also the host plant for most of the monarchs life cycle.

countless monarch butterflies roosting in a eucalyptus tree

What can you do?

There are several things you can do to help these epic travelers along the way.

Grow Native Plants

Planting a few native plants can help out not only monarchs but other native pollinators in our state. Conservationists are calling on gardeners nationwide to plant native nectar sources for butterflies along with milkweed for larvae. The Xerces Society provides help on finding native milkweed seeds and germinating them. Local to Santa Clara County are Asclepias californica, cordifolia (Heart Leaf), fascicularis (Narrow Leaf) and speciosa (Showy). For regional planting guides, check out the Pollinator Partnership.

Become a Citizen Scientist

You can also help out by joining in on some citizen science: report the monarch butterflies you see. Despite having been studied for a very long time, it wasn't until 1976 that the monarch's winter resting site in Mexico was discovered by citizen scientists working for Fred Urquhart. If you see a group traveling, resting or roosting, report the sighting to Journey North. You can see current postings on their maps and sightings of the migration in progress.

Learn More

Follow these links to learn more about Monarchs:

Read More

Read more about it at the Library:

Explore the California Room

Check out these items in the California Room:

illustration of little girl forming a traveling company with monarch butterflies
Los Angeles Herald, Number 129, 7 February 1909
Wise Fairy Visits Curious Little Girl country Visitor Asks Many Questions Concerning Habits of the Butterflies and Her Wish to Learn Everything She Wants to Know Is Finally Gratified in Startling and Effective Manner, and She Discovers Many Interesting Traits of These Winged Beauties and Their Far Flights Into Southern Climes


Thank you for this essay and the pictures. Enchanted with Monarchs in my rose garden, I went to my nearby nursery and purchased milkweed. Imagine my delight to find baby caterpillars emerge and start eating the leaves. I thought I had to travel to Mexico to see the beauty of them in full abundance. How nice that more and more are seen in California. I was blown away to read that through some extraordinary sense, the next generation with return to the same tree on the same street in the same town by some knowingness. Imagine that without a GPS device.

Karen: How wonderful! What was the name of the nursery where you were able to purchase milkweed? It is nice to be able find a nearby resource. I am always blown away by the incredible sense of direction in our migrating friends.

Planted some. Waiting for results. Thanks for the idea!!

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