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A small sensor used to track the migratory patterns of monarch butterflies

Millions of monarch butterflies migrate each fall to a specific group of mountain peaks in central Mexico. How exactly they navigate to their winter home, and how they choose their path, is a subject of great interest to scientists – especially as climate change redirects their chosen path.

Inhee Lee, an assistant professor of electrical and computer engineering at the University of Pittsburgh, is part of a team developing a tracking system that could be attached to monarch butterflies and transmit data on their location throughout the three-month journey. to the south. A paper detailing these results recently won the best paper award at the MobiCom 2021 conference.

“Tracking animal migration is a critical ecosystem indicator,” Lee said. “Migrants travel long distances across entire continents, and this can give us unprecedented insight into their migratory routes, how the environment around them changes, and how species interactions are affected by the evolution of movements and distributions.”

Previously, only highly migratory animals could be tracked for a significant portion of their migration. Migratory insects, however, make up a huge portion of the total number of migrants across the world. To track them, the researchers created a new wireless detection platform called mSAIL, specially designed for migrating monarchs.

The tiny 62mg, 8×8×2.6mm chip is attached to the butterfly’s back and can simultaneously measure light intensity and temperature, wirelessly communicating this information to researchers once the butterflies have reached their destination. The system will use a deep learning-based location algorithm to reconstruct the butterfly’s migration path after its journey.

To test the potential of mSAIL, the researchers attached the system to a living monarch butterfly in a botanical garden. The chip was stuck to the butterfly; it had no problem flying, opening and closing its wings, or performing any other normal butterfly behavior with the chip in place.

mSAIL is an extension of work Lee did while a research assistant at the University of Michigan. mSAIL integrates previously developed integrated circuits into a 3D stacked form factor and demonstrates, for the first time, the feasibility of locating and tracking individual butterflies using the new on-board system.

The next stage of the project is to mass-produce over 100 mSAIL sensors that can operate reliably during the monarch’s three-month migration period. Researchers will release the mSAIL-equipped butterflies at various locations around the United States and check with the sensors for the butterflies’ well-established resting places – such as in the western Lake Erie archipelago – and the last overwintering site at central Mexico. Eventually, the team hopes to add an atmospheric pressure sensor to mSAIL, which will allow it to determine altitude and more accurately assess the trajectory of butterflies.

The article, “mSAIL: Milligram-Scale Multi-Modal Sensor Platform for Monarch Butterfly Migration Tracking,” was edited by Lee and Roger Hsiao, who was an undergraduate student at the University of Michigan and currently a graduate student at the UC Berkeley. Other co-authors come from Pitt, the University of Michigan, the University of Nebraska and the University of Delaware.

Source of the story:

Materials provided by University of Pittsburgh. Original written by Maggie Lindenberg. Note: Content may be edited for style and length.