https://phys.org/news/2018-05-scientists-storks-migrate-africa-autumn.html

Andrea Flack and Wolfgang Fiedler have been visiting storks' nests on the western shore of Lake Constance. The aerial ladder of the fire brigade raises them to the stork nests at lofty heights so that they can strap small tracking devices onto the backs of the nestlings. The aim is to follow Louis and 60 other young storks on their migration. The instruments, which weigh less than 60 grams, record the GPS coordinates of the birds' locations. They also measure the animals' movements using accelerometers. This allows the researchers to determine whether and how the birds are moving.

For Louis and his nest mates, the harmless procedure is over in just a few minutes. Fully engaged in perfecting their flying skills, it is likely that they very soon forget the strange encounter with the scientists. For the researchers, however, the work has only just begun. From now on, they will collect and evaluate huge volumes of data, because the tracking devices log the storks' GPS coordinates every second for two to five minutes every 15 minutes, over a period of weeks. Once a day, the devices send a text message containing the location and movement data via the local mobile network, just like a mobile phone.