Monarch butterflies flutter around the globe
Photo: Richard Ellis/Getty Images
Efforts began in the 1930s to track the Monarchs' migration routes. In the 1970s, researchers found 12 forested spots in Mexico where the butterflies liked to flock in winter. The Mexican government labeled five of the sites as protected biosphere areas in 1986, but privately owned plots continue to be logged, which reduces the Monarchs' habitat.
Read more: Fewer monarch butterflies are becoming 'snowbirds'