For the first time, nearly 500 Monarch butterflies from Canada and the United States are embarking on their journey to the oyamel forests in Mexico with a tiny transmitter attached to their thorax, a device that weighs just 60 milligrams, equivalent to a grain of rice.
The initiative, known as the Monarch Collaboration Project and led by David La Puma (former director of the Cape May Bird Observatory and currently at Cellular Tracking Technologies, CTT), aims to study migration with an unprecedented level of detail to inform conservation decisions.
What technology do these Monarch boats use?
The device, identified as BlūMorpho , was designed by CTT to minimize its impact on flight: it weighs approximately 60 mg and operates in the 2,4 GHz band . It is powered by solar energy and Bluetooth , allowing it to detect the movement of butterflies using both new tools and existing networks, including Motus towers and Terra stations.
These transmitters, with their ultra-light profile and length of only a few centimeters, can send information in real time if a data plan is subscribed to; each unit costs approximately $175 , according to estimates shared by the team.
The team and the scientific collaboration
The project is led by David La Puma and includes the participation of CTT, Cape May Point Science Center, and the Monarch Project . Eduardo Rendón, from WWF Mexico , praised the incorporation of this technology, emphasizing that migration routes are not always linear and that weather can divert the insects, so having precise trajectories will help in making better decisions at the overwintering sanctuaries.
Initial monitoring records
RocÃo Treviño, coordinator of the Correo Real program , confirmed that the first female with a transmitter recently crossed into Mexico through Coahuila , demonstrating the potential of the technology to document the border crossing.
One of the most detailed cases is specimen LPM021 , released on September 13 in Long Point (Ontario, Canada), which after 37 days and 2.362 kilometers was detected on October 19 at 16:53 p.m. near the Amistad Dam, in Ciudad Acuña (Coahuila).
Citizen participation
The project includes a free mobile phone app that allows anyone to detect the signals of the tagged butterflies via Bluetooth and send those records to the researchers, expanding the scope of the study through citizen science.
With the contribution of users spread across the territory, the initiative aims to weave a large wildlife tracking network by combining personal receivers, Motus towers and collaborative stations.
Data retention and use
The central objective is to turn monitoring into actionable information: identifying critical passage and resting areas, understanding how meteorological events influence them, and prioritizing interventions that strengthen the conservation of the species.
Having accurate routes and schedules will make it easier to adjust management measures both in the oyamel hibernation sanctuaries and along the migratory corridor , where habitat loss remains a threat.
Of interest to Europe and Spain
The technological leap in insect telemetry opens the door to applying similar methodologies in Europe: research teams and observation networks could take advantage of standardized protocols and citizen science to study the movements of butterflies and other pollinators on the continent, including Spain.
This progress in tracking 500 Monarch butterflies with ultralight transmitters , supported by solar energy and citizen collaboration, is beginning to outline key routes and behaviors and provides a solid basis for better-informed conservation decisions.
