Scientists at Althouse and Meade, Inc. used new radio telemetry technology to examine winter movements and demography of monarch butterflies (Danaus plexippus) on the Central Coast, California. Although western monarchs are known to occupy and move between the network of overwintering sites throughout California, movements of individuals within the overwintering season are poorly known. This lack of information limits the abilities of land managers and scientists from across the monarch’s overwintering range to design optimal conservation and habitat restoration plans. In this study, our team attached tiny radio transmitters to monarch butterflies at three overwintering sites: Ellwood Mesa, Gaviota State Park, and Pismo State Beach. We track the locations of individuals using a combination of Motus tower equiped with 2.4 GHz receivers and Bluetooth enabled devices. We invited the public to help us record the locations of monarchs with the Project Monarch app that leverages the phone’s Bluetooth receiver to detect radio transmitters. The study is underway and results will provide novel information on residence time of monarchs at individual sites, movements among sites, movement rates, home range sizes, and survival. 

Charis van der Heide is a research biologist who has been studying and monitoring the movements of monarch butterflies on the central coast of California for over 20 years. She has a B.S. in Biological Sciences from Cal Poly San Luis Obispo where she started researching and tagging monarch butterflies. She is the regional coordinator for the Xerces Society’s Western Monarch Counts in Santa Barbara County. She works in the environmental consulting field and has lead many research projects on monarch biology and conservation. She designs habitat management plans for monarch butterfly overwintering sites on the central coast of California with Althouse & Meade, Inc.