Global declines in pollinator abundance and species diversity are a threat to ecosystem function and human food security. Although there’s guidance to support land managers in protecting pollinators, pollinator declines are continuing. In part, this is because there hasn’t been a way to study how pollinator behaviour, especially foraging, and pollinator survival are affected by the ways humans change landscapes.

To address this problem, we have developed technology to track individual pollinators as they travel across landscapes in real time. Our approach builds on existing harmonic radar systems, and moves the technology forward by using the smallest harmonic radar tag ever developed, and reducing the size of the radar transmitter and receiver so that the transmitter can be hand-held and the receiver carried on an Unmanned Aerial Vehicle (UAV, drone). Carrying the receiver on a UAV also reduces signal strength loss over distance and interference from vegetation. In addition to the radar system, we have developed a parallel visual tracking system using a retroreflective surface added to the harmonic radar tag, a digital camera on the UAV filtered to detect only 940nm radiation, and a ring of 940nm LEDs on the camera. 940nm radiation is absorbed by water in the Earth’s atmosphere, so the camera sees grey, except for the point of light from the retroreflective tag returning the light from the LED ring. Now that this technology is in late stage development, we hope to begin tracking pollinators! In addition to tracking pollinators, we’ve started adapting the technology for tracking migrating birds, and we hope to move on to other tracking challenges in the future.