New Insights on Butterfly Migration Revealed

A female monarch butterfly numbered B6679 was named the “first migrant from the Pacific Northwest confirmed to be actively reproducing within the winter breeding population of monarchs in Southern California,” announced entomologist Dr. David James of the Monarch Tagging Program of Washington State University.

“Typically fall migrating butterflies do not reproduce when they reach their winter roosts in California,” said James. “In February and March they move inland to breeding areas, and their offspring begin the multi-generation journey north in May and June.” No migrant butterfly has ever been observed breeding within the winter breeding population of monarchs in Southern California.

In August 2017, Akimi King, a Fish and Wildlife biologist at the Klamath Falls office, had tagged a monarch butterfly in Oregon using one of James’s tags. Nineteen days and 545 miles later, B6679 was discovered by Santa Barbara resident Cathy Fletcher, who noticed a tagged adult butterfly laying eggs in her garden. Fletcher gently recorded the data from the butterfly and reported her findings, which James published in the Journal of the Lepidopterists’ Society this September.

These unique findings have revolutionized butterfly science, changing attitudes on butterfly migration.