As students of migration ecology, we ultimately seek the ability to know everything about all individuals at all times. Unfortunately, the technology required to do this for most flying migratory animals, particularly the smallest bodied ones, does not exist. Therefore, biologists have to use a combination of complementary tools such as tracking-based geolocators, GPS and GSM, GPS and Geolocation data loggers, as well as isoptopic, genetic, and good old bird banding/ringing to discover the complete life histories of migratory animals. While often viewed as having competing value, these tools are undeniably complementary, and researchers need to employ the best tool for the job given the specific questions and study system in mind.