Scientists love the data they get by attaching electronic tags to animals, but these devices can be a literal drag. For animals that fly or swim, tags can mess up their mechanics and force them to spend more energy. That's what scientists expected to see when they studied dolphins with data loggers suction-cupped to their backs. To their surprise, they found instead that these dolphins refused to work any harder at all.
When scientists attach a data-logging tag to an animal, they try to d