RFID technology has been used to monitor hummingbirds before, but this is the first time it has been used to monitor multiple hummingbirds at feeders at the same time, which is critical when studying their interactions.
The study, conducted September 2016 to March 2018, recorded about 65,500 visits to seven feeding stations across three California sites. These included the UC Davis Arboretum Nursery, a private home in Winters and The Gottlieb Native Garden in Beverly Hills.