Monarch Migration

Peninsula Point is at the southern tip of Stonington Peninsula, south of Route 2. You can reach Peninsula Point by going south on County Road 513 (or County Road 511 to 513).

Although the migration is different each year, monarchs can migrate anytime from late July August through mid- September.

• The best time to look for monarchs at Peninsula Point are when overnight temperatures begin to cool and there is a cool front from the north.
• If the monarchs overnight at Peninsula Point, they often leave early in the morning once the sun has dried the dew from their wings.

• Monarchs only travel during the day and need to find a roost at night.
• Monarchs gather close together during the cool autumn evenings.
• Roost sites are important to the monarch migration.
• Many of these locations are used year after year.
• Often pine, fir and cedar trees are chosen for roosting.
• These trees have thick canopies that moderate the temperature and humidity at the roost site.
• In the mornings, monarchs bask in the sunlight to warm themselves.

• Yes, Peninsula Point is known for yearly gatherings of monarchs, but you can view monarchs at other peninsulas too.
• Monarchs gather on peninsula when traveling south.
• The butterflies use features likes the Great Lakes shorelines as corridors.
• The shape of the peninsula is a funnel for migrating butterflies.
• At its tip, the monarchs find the shortest distance across open water.
• Monarchs gather along the shore to wait for a gentle breeze to help them across.

Monarchs migrating from Peninsula Point are thought to go to the Door County Peninsula in Wisconsin.

Eastern North American monarchs fly south using several flyways then merge into a single flyway in Central Texas. It is truly amazing that these monarchs know the way to the overwintering sites even though this migrating generation has never been to Mexico!

Monarchs living west of the Rocky Mountain range in North America overwinter in California along the Pacific coast near Santa Cruz and San Diego. Here microclimatic conditions are very similar to that in central Mexico. Monarchs roost in eucalyptus, Monterey pines, and Monterey cypresses in California.

In Mexico, monarchs roost for the winter in oyamel fir forests at an elevation of 2,400 to 3,600 meters (nearly 2 miles above sea level). The mountain hillsides of oyamel forest provide an ideal microclimate for the butterflies. Here temperatures range from 0 to 15 degrees Celsius. If the temperature is lower, the monarchs will be forced to use their fat reserves. The humidity in the oyamel forest assures the monarchs won’t dry out allowing them to conserve their energy.

The eastern population of North America’s monarchs overwinters in the same 11 to 12 mountain areas in the States of Mexico and Michoacán from October to late March.

Researchers are still investigating what directional aids monarchs use to find their overwintering location. It appears to be a combination of directional aids such as the magnetic pull of the earth and the position of the sun among others, not one in particular.

Monarchs glide on thermals to assist them in reaching their destination.

The monarch research project has been run by a small crew of very dedicated volunteers. From the beginning in 1994 when C. J. Meitner received a small grant from Wildlife Unlimited of Delta County to conduct a study to determine the significance of the annual congregation of monarch butterflies at Peninsula Point, Wildlife Unlimited of Delta County has been a yearly supporter of the research project, allowing us to pay mileage reimbursement to the volunteers.

Monarch Research Project (run exclusively by volunteers) at Peninsula Point includes:

• Migration Census Monitoring began in 1996 (tagging is also conducted during monarch census with tags from the Monarch Watch Program). Annual monarch migration census is conducted in only a couple of locations in the U.S. with the other being at Cape May New Jersey.
• Monarch Larva Monitoring Project (MLMP- University of Minnesota Program) began in 1997. Peninsula Point was one of the first sites. Protocol developed at Peninsula Point has been used at other sites across North America. There are over 1,000 MLMP monitoring sites today.

If you are interested in volunteering or would like more information on volunteering visit our monarch volunteering page.

Reporting when and what you see in plants throughout the seasons is a very important step to helping both humans and animals adapt to a rapidly changing landscape. The U.S. Forest Service has a collection of Citizen Science projects, including those for pollinators.

Publications and Reports

• Monarch Butterfly - North America's Migrating Insect (pdf)

Articles and Stories

• Making a Difference for Pollinators. Pollinators are increasingly imperiled. Protection and enhancement of habitat is critical.
• Volunteers Needed for Citizen Science Monarch Butterfly Monitoring Project. Peninsula Point is known not only for its lighthouse and wonderful bird watching opportunities, monarch butterflies can be found throughout the summer nectaring on the many wildflowers and milkweed plants and congregating on the cedar trees prior to migration in the early fall.
• Hiawatha National Forest's Monarch Butterfly Research Project Receives the Wings Across the Americas Award.

Links and More Information

• Journey North. Report Your Monarch Sightings ( html)
• Celebrating Wildflowers. Monarch Butterflies in North America (html)
• Why Monarchs? Explore the ways that monarch habitat and conservation helps people, other wildlife and the environment.
• Pollinator Partnership is a partner of the U.S. Forest Service and the largest non-profit in the world dedicated exclusively to the protection and promotion of pollinators and their ecosystems.