The field of urban evolution is relatively young, but researchers have been fascinated by animal movement through cities for quite some time. Recently, I was perusing the archives of the Journal of the Lepidopterists’ Society and came across a note by Sidney Hessel detailing the movements of monarch butterflies through Manhattan. He observed 82 monarchs flying south throughout the city on October 2, 1968. Interestingly, individuals observed at Battery Park were not deterred by open water and continued flying south toward Staten Island. The full account is available for free on the journal repository.
While the fact that monarchs from as far north as Canada fly south to Mexico each fall is common knowledge today, this was not known when Hessel wrote his report. The full extent of their migration was not confirmed until 1976, when a monarch tagged in Minnesota was recovered in Mexico, over 1700 miles away. Read more about the history of this discovery in the StarTribune.
Tagging continues to be an important tool to study monarch movement and monitor their population. If you see a tagged monarch this fall, you can visit Monarch Watch to learn more and report your sighting!
We still have a long way to go to understand if urban areas affect monarchs and their migration. However, observations such as Hessel’s in 1968 and modern-day tagging efforts are excellent first steps.
Featured image: Cluster of monarch butterflies on a branch of an Oyamel fir tree in Mexico.
Photo by Ann Ryan/Monarch Watch.
Google Scholar Profile
- Migrating Monarchs in Manhattan - October 8, 2019
- Urban Evolution at Behaviour 2019 - July 18, 2019
- Evolution 2019: Adaptation to Coastal Stressors in Oyster Larvae - June 24, 2019
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