Monarchs on Mackinac
The Monarchs have begun their Migration and are choosing Mackinac Island to wait out the weather.
For the last few weeks, all you can see while riding your bike around the island are hundreds upon hundreds of Monarch butterflies. The migration has started and they are coming to the island in droves. This year, inclement weather has forced them to hunker down for two weeks and counting!
The migration is an incredible thing to witness, the summer Monarchs, which only live for about 4 weeks, are beginning to phase out and the Migratory (winter) Monarchs, or the Super Generation, is starting.
This generational difference is caused by changes in weather, aging milkweed, nectar sources and shorter photo periods. With fall quickly approaching, plants are beginning to die back and milkweed, or the caterpillar food, is beginning to brown. The Monarchs emerging in these cooler temperatures are slightly different from their parents and grandparents. Butterflies have a gene that produces collagen which influences flight muscle structure and growth. In the Super Generation, this gene, produces lower levels of collagen than in the summer Monarchs. Less collagen in the flight muscles, increases the endurance of migratory Monarchs so they can physically make the 3000 mile trip to Mexico (1).
On top of all that, when the Monarchs of the Super Generation, emerge from their chrysalises, cold weather stunts their development and sends them into a reproductive diapause, meaning they are not sexually active (2). Due to this HUGE energy reserve they have the ability to live for up to 9 months!
Once the monarchs make the trip all the way down to the State of Michoacan in Mexico. They overwinter is specific forested areas because they feed on the sap of Oyamel Firs, which provide enough energy to survive the cold winter climes.
We are thrilled to witness this magical experience and are participating in the Monarch Watch Tagging Program. We have purchased 100 tags and are hoping to use all of them. Stay tuned for updates and photos!
Sources
- Secondary Source, Originally published October 1, 2014 in Nature https://news.uchicago.edu/story/genetic-secrets-monarch-butterfly-revealed
- https://www.fws.gov/midwest/news/MonarchMigrationFall17.html
Informational Resources
This is an awesome article that discusses how the Monarch Antennae act like compasses using sunlight https://news.nationalgeographic.com/news/2014/06/140624-monarch-butterfly-migration-magnetic-compass-insect-science/ —– Going to write a blog about this article, Super cool!
Tagging program information, be a Citizen Scientist! https://www.monarchwatch.org/