In Dialogue on Miracles, the thirteenth-century preacher and historian Caesarius of Heisterbach tells of a man curious to discover the origin of the migratory swallows that appeared at his house every spring. Catching one of them, he attached a note to its leg that read, “O swallow, where do you live in winter?” The following spring, a bird appeared with a reply attached to its leg: “In Asia, at Peter’s house.”

To better understand the migration patterns of American robins, Georgetown University researchers attached “tiny metal backpacks” to them that use an antenna on the International Space Station to pinpoint the birds’ locations within thirty feet. Martin Wikelski, director of the Max Planck Institute of Animal Behavior, described the technology as a harbinger of “an ‘internet of animals’—a collection of sensors around the world giving us a better picture of the movement of life on the planet.”