Wildlife tracking to fill gaps in monarch migration research

Every fall, monarch butterflies travel an extraordinary migration from North America to Mexico, fueled by nectar from Iowa's fall-blooming wildflowers. However, the precise pathways they take and how their journey is influenced by weather and other factors have remained largely unknown. Researchers at Iowa State are leveraging cutting-edge wildlife tracking technology, specifically the lightweight BlūMorpho tags, to monitor 100 monarchs that have been raised over the summer.

These tags, which utilize Bluetooth technology, offer real-time location data, a significant advancement over previous methods that only provided information on whether a butterfly reached Mexico. John Pleasants, an expert in the field, explains that these new tags enable a comprehensive understanding of the monarchs' journey and the impact of weather conditions.

The team, which includes Katherine Kral-O Brien, Mykayla Hagaman, and Nathan Brockman, has divided the reared monarchs into three groups based on different rearing conditions: entirely indoors, entirely outdoors, and indoors only during the final larval stages. They will compare the flight data of 75 reared monarchs with that of 25 wild-caught monarchs to determine if rearing conditions impact survival or the butterflies' ability to migrate correctly southwestward during the approximately eight-week journey.

This study, part of a broader project with researchers at the University of Guelph in Ontario, Canada, aims to uncover the best strategies to support monarch populations, which have declined by up to 80%. Iowa plays a crucial role in monarch conservation, as many monarchs originating in the Midwest reach the overwintering grounds in Mexico, and the findings could have significant implications for landscape modifications to support monarch conservation efforts.