Like jets radioing in their call signs to air traffic control, bees’ buzzing could help scientists know who’s pollinating what over large swaths of land, leading to better farming methods and more productive crops. In the past, farmers have relied on visual surveys for insight into pollinator activity—a time-consuming and expensive process. But one team of researchers thought the bees’ buzzes might do a better job of giving them away. So they cataloged the body traits of different bees—like tongue length, wing length, and body size—that influence both which plants they pollinate and the acoustic frequency of their buzzing. The researchers then nailed down the acoustic signatures of two bumble bee species near Boulder, Colorado, Bombus balteatus (above) and B. sylvicola.
The researchers used field recording equipment to listen for those frequencies in different wildflower patches over two flowering seasons. The buzzes alone allowed the researchers to estimate the number of bees in a given area, they report today in PLOS ONE. What’s more, by systematically excluding certain bee traits—like shorter tongues—and then tracking which plants got pollinated in a given area, they were able to link certain acoustic frequencies to the successful pollination of different flowering clovers, including Trifolium dasyphyllum and T. parryi. That means that they could—in theory—figure out which bees are where, and what work they do, during each pollinating season. And by actively monitoring the soundscapes around their fields, growers could know whether they have the right bees for the job—or whether they need to call in reinforcements.