Research overview: the origins of wildlife radio-telemetry

This overview traces how VHF radio-telemetry emerged in the late 1950s and 1960s, when biologists such as the Craighead brothers fitted grizzly bears in Yellowstone with radio collars and proved that individual wild animals could be followed continuously rather than glimpsed by chance. The same transmitter-and-receiver approach was quickly adopted for carnivores, including the earliest collared mountain lions. Early systems demanded constant fieldwork: a researcher triangulated each fix by hand, often from a mountaintop or a circling aircraft, recording only a handful of locations per week. Reviewing this period clarifies why later automation through GPS was so transformative, and why the conceptual vocabulary of home range, fix, and triangulation remains central to felid movement ecology today.