Counting bees has an awkward catch. The usual way to check how bees are doing is to set out small, colorful cups of soapy water, which trap and kill the insects so experts can identify them later. Getting an accurate count can kill tens of thousands of bees. That’s a rough trade when populations of many pollinators, bumble bees included, have been crashing for decades.
The clever bit
Instead of trapping bees, the team listens to them. Bees make distinctive sounds when they fly, and bumble bees make a separate buzz when they shake pollen loose from a flower. Laura Figueroa, an ecologist at UMass Amherst, and colleagues at Cornell trained two AI sound models on 594 field recordings made over five years at 43 sites in the northeastern U.S. One model picks out bee activity in general. The other tells honey bee flight from bumble bee flight and bumble bee pollen-shaking.
In the team’s peer-reviewed paper, published October 12, the models were checked against trained observers counting bees in flower patches, and the two sets of counts tracked each other closely. At the models’ strictest setting, 93% to 97% of the sounds they flagged really were bees. Both models are now built into Raven Pro, a sound-analysis program from the Cornell Lab of Ornithology that many wildlife researchers already use, and the team’s recordings are public on Dryad.
I’ve been working with bees for over a decade and can tell a bumble bee from a honeybee in the field by sound. If my brain can easily distinguish between bee categories, then we should be able to train an AI model to do it, too.
— Laura Figueroa, assistant professor of environmental conservation, UMass Amherst, via umass.edu
Hooray
Scientists can check on bees by leaving a recorder in a flower patch, and no bees have to die for the count. It also reaches places that are hard to survey in person. Figueroa points to tree canopies and fields during heat waves, and the paper suggests the bumble bee model could help growers of buzz-pollinated crops like tomatoes and blueberries decide how many bumble bee colonies to use and where to put them.
What comes next
The authors want the models to learn a wider range of bees and other pollinating insects. Figueroa says the tool is meant to work alongside traditional surveys. It hears best up close, and counting individual bee species still depends on traditional traps.