The National Commission of Natural Protected Areas (Conanp) has launched an innovative monitoring system to more precisely study the migration of the Monarch butterfly in Mexico. The project is being developed in coordination with the World Wildlife Fund (WWF), with technical support from Cellular Tracking Technologies and the Cape May Point Arts and Science Center. The initiative consists of placing BluSeries sensors—ultralight radio transmitters with digital coding—on specimens in the Monarch Butterfly Biosphere Reserve, located between the State of Mexico and Michoacán. Each device weighs only 0.06 grams and has a small solar panel that will allow tracking the insects' journey during their stay in hibernation colonies and during their spring migration. For this study, specialists installed 175 sensors in communities and ejidos (communal lands) in both states. In the State of Mexico, work was carried out in La Mesa, San José del Rincón, San Francisco Oxtotilpan, and San Antonio Albarranes in Temascaltepec. In Michoacán, monitoring is being done in El Rosario, Sierra Chincua, and the ejido Crescencio Morales. Monitoring without harming the specimens Conanp detailed that, to ensure the well-being of the butterflies, the tagging was done using a specialized methodology. The specimens were collected with nets, weighed, measured, and physically examined before attaching the sensor with a special adhesive and materials designed to protect their wings. Each device was linked with a unique code to identify the sanctuary of origin for each butterfly and to track their movements individually through the Project Monarch application. As part of the initial results, Conanp reported that nine Monarch butterflies have already crossed the border into the United States, while five more are within U.S. territory. Meanwhile, the monitoring yielded an unprecedented finding: for the first time, it was detected that butterflies marked in the fall are already advancing northward on their return journey, which opens new possibilities for better understanding their migratory route.
