An orange and black monarch on light purple bunches of flowers. There is a small square of plastic tag on its back, with a long antennae sticking off of the tag.

The Sky’s the Limit for Monarchs Wearing Solar-Powered Radio Tags

Dear Readers,

Our coworker Kass Urban-Mead, Pollinator Conservation Specialist, recently visited Cape May Point Science Center (CMPSC) to see one of our Xerces habitat kit sites in their courtyard pollinator garden, and while there had a chance to see Cellular Tracking Technologies’ (CTT) new monarch tagging program, Project Monarch, in action. 

We offered to let CTT do a guest post for Bee City USA, in the hopes that some of our East Coast Bee Cities and Bee Campuses might find this new community science program a worthwhile activity for their communities. We hope you enjoy learning how it works!

– Bee City USA and Bee Campus USA Team

The Sky’s the Limit for Monarchs Wearing  Solar-Powered Radio Tags

By Kelly Ball, Sean Burcher, and David La Puma
Cellular Tracking Technologies

8 smiling adults stand behind a white table outside, with a white building in the background.
Credit: Susan Allen

On September 21, 2023, in the courtyard pollinator garden of the Cape May Point Science Center (CMPSC), a group of CMPSC employees and scientists from Cellular Tracking Technologies (CTT), a wildlife telemetry company based in Cape May, NJ, officially launched Project Monarch. Conceived of as a community science project that allows the general public to participate in data collection of monarch migratory movement, Project Monarch utilizes digitally coded radio tags that transmit at 2.4GHz—the same frequency as Bluetooth devices such as smartphones and wireless speakers. This feature means that any modern smartphone can potentially be a receiver for these tags! To make this technology work, CTT engineers developed a smartphone app, appropriately named Project Monarch.

Following the kickoff event in September, CTT staff and volunteers conducted a small number of tagging demos throughout the fall that were open to the public. These events were made possible with help from many other local individuals and organizations. CTT enlisted local naturalist and long-time monarch butterfly champion, Mark Garland, to provide general project guidance and planning for attachment of tracking devices. Project Monarch also augments the long-term data collection that has been conducted for many years by New Jersey Audubon’s Monarch Monitoring Project, which deployed the new radio tags at its own demos.

Why Tag Monarchs?

The data generated by community scientists using the app will allow scientists to track the movements of monarch butterflies in detail never previously imagined, including how monarchs utilize key stopping points along migratory routes, as well as details about the speed and direction of migration, helping identify the most important sites for habitat conservation and restoration. Ultimately, this technology can help guide conservation planning and lead to increases in monarch populations.

An orange and black monarch on light purple bunches of flowers. There is a small square of plastic tag on its back, with a long antennae sticking off of the tag.
Monarch with tag. Credit: Sheldon Blackshire
How Do the Tags Work?

Attached via eyelash glue, of all things, to the monarch’s posterior thorax, solar-powered 60-milligram BlūMorpho radio tags are lightweight enough to affix to migratory butterflies. The tags are active when there is light on the solar panel. As CTT’s engineering team developed the tags, one of the major considerations was the need for the finished product to be ultra-lightweight. This meant that they could not be outfitted with a battery, which would have added significantly to the final product weight. Instead, each tag has a tiny solar panel that, when exposed to sunlight, is able to harvest enough energy to send a brief transmission. When a tag remains in the sun, it will continue to transmit about once a second, indefinitely! 

The hands and arms of two people. One holding a monarch, one applying eyelash glue.
Applying eyelash glue. Credit: Susan Allen
Field of Monarchs: Build an App, and They Will Search

Theoretically, by encouraging local and coastal community scientists to download the Project Monarch app (available for both iOS and Android), the smartphones that most people carry for everyday use can become receivers for the tagged butterflies. CTT’s Sean Burcher ensured that the app allowed for users to easily access a tag name, when the monarch was originally tagged, and how far it had flown from the initial tagging location. A particularly popular feature for encouraging engagement with the app is a Leaderboard view that displays who has detected the most monarchs.

A screenshot of a map with butterfly icons plotted on it.
Image credit: Cellular Tracking Technologies (CTT)
A screenshot of the Project Monarch app with three monarchs listed.
Image credit: Cellular Tracking Technologies (CTT)
A screenshot of the Project Monarch app with a profile on one monarch displayed.
Image credit: Cellular Tracking Technologies (CTT)
Satellite map with yellow lines plotted.
This map of Cape May Island, the southernmost point in New Jersey, shows detections for tagged monarch “Xerces.” The Cape May Point Science Center (CMPSC) is indicated at bottom right. Each spot with a butterfly represents a location where there was a cluster of detections. All of the red dots are detection locations, but many are covered by the butterfly icons. However, it is evident that many detections occurred near the CMPSC, which was the primary tagging site. Xerces actually ended up coming back to the CMPSC after a few days and that was the last spot where it was detected. Image credit: Cellular Tracking Technologies (CTT)
A large group of adults stand together on a sunny day. Many are looking down at their phones.
Credit: Susan Allen

Initially, all transmitted data is reviewed by CMPSC scientists, who foresee scientists from partner organizations, universities, and collaborators then accessing this data for use in publications. Ultimately, all data will be made publicly available for download by anyone. If people or organizations are interested in reviewing data before it is available publicly, CMPSC encourages them to contact the organization directly, as forming new collaborations and sharing data with collaborators will increase the project’s reach.

Applications Beyond Community Science

While the Project Monarch app was developed specifically for community scientists, and to encourage broader public engagement with wildlife conservation, the CTT product development team ensured that other tools also be available for more specialized wildlife telemetry. In this way, the greater scientific community is able to capitalize on this technological breakthrough for larger-scale studies and building out a robust network with a capacity to track migratory monarchs over their entire range.

Two adults in blue shirts stand on a beach facing each other. The cameraperson's hand holds an antennae.
Engineer Sean Burcher, CEO Mike Lanzone, and Marketing Specialist Kelly Ball (holding Sidekick) test the CTT Sidekick and CTT Mobile app at a local Cape May beach. Credit: Kelly Ball

Soon, stationary receivers outfitted with a plug-in to detect radio tags will also be able to function as receivers for migratory monarchs. The CTT team envisions a future where additional autonomous monitoring stations are strategically placed along the flyways where monarchs migrate and stop over to pick up signals from individuals wearing radio tags. Augmenting the existing Motus Wildlife Tracking network in places where it does not already exist, but which are important along monarch routes (like the mountains of Mexico and at specific roost sites on the California coast), is a crucial component. Why? Getting existing Motus stations upgraded to accept those tags will have a major impact on the capacity to track monarch migration over long distances.

Adults and kids stand on a lawn on a sunny day. Some are looking down at their phones.
Monarch enthusiasts look at the tags—and for monarchs! Credit: Kelly Ball
Project Monarch App Stats as of December 5, 2023
  • Number of tagged monarchs = 76
  • Number of active user accounts = 3,294
  • Number of users who uploaded detections = 264
  • Total number of detections from all monarchs  = 253,597
A person in sunglasses, a black shirt, and broad-brimmed hat stands with an arm extended, A black and orange monarch butterfly is on their hand. A crowd of people watch and hold up their phones.
Credit: Susan Allen

Share this post


Help us empower communities to protect the life that sustains us! DONATE