Migrating animals have for a long time been tracked by recapturing tagged individuals. More recently, radio-telemetry, which requires an observer to physically follow the tagged animal, has been used.

Animal migration : a context for using new techniques and approaches / Keith A. Hobson and D. Ryan Norris -- An introduction to light stable isotopes for use in terrestrial animal migration studies / ...

New maps show the massive impact of fencing on the long-distance movements of one of Africa’s most iconic migratory wildlife ...

Tracking units on the shell of a wood turtle. The tracking information these GPS units collect is used to understand how wood turtles move throughout the year. Image credit: Smithsonian's Movement of ...