Bees are far more accurate navigators than scientists once realized. Researchers at the University of Freiburg have discovered that individual bees follow unique, highly consistent flight routes and can repeat them with remarkable accuracy, relying on landmarks in the landscape to help them stay on course.
The study was led by neurobiologist and behavioral biologist Professor Andrew Straw, whose team used drones to monitor bees as they moved between their hives and food sources in an agricultural environment about 120 meters away.
To track the insects in flight, the researchers used a technique developed by Stroh’s research group called fast lock-on (FLO) tracking. This method requires attaching a small reflective marker to each bee. A computer on board the drone analyzes the reflected light and can identify and track bees in flight within milliseconds.
The observations revealed that each bee follows its own preferred route, which it maintains with great precision on both its outward and return journeys. Bees also appear to use features of the surrounding landscape to guide their journey.
“Our tracking system makes it possible for the first time to record high-resolution 3D flight paths of bees in natural landscapes,” explains Stroh. “Our records show that each bee has its own preferred route and flies with great precision. It’s no exaggeration to say that each bee has its own personality.”
How bees use landmarks to navigate
Researchers analyzed 255 flight paths collected near Kaiserstuhl, Germany. The study area included hedgerows, cornfields, and trees that stood between nest boxes and food sources and obstructed direct routes.
“We found that there was a high degree of precision in their flight paths. Individual bees repeated their individual flight paths almost exactly over several flights. They often flew only a few centimeters away from their previous path,” Stroh emphasizes.
The most consistent flight behavior occurred near prominent landscape features, especially trees. The biggest changes appeared when the bees flew over cornfields, where the landscape provided few clear visual cues.
“Our results suggest that visual landmarks aid bee navigation and increase the accuracy of flight paths,” Stroh explains. In contrast, visually monotonous environments increase bees’ uncertainty.
Bee Navigation vs. Waggle Dance
The discovery also shed new light on the famous waggle dance that bees use to communicate the location of food sources to other members of the colony.
“We’ve known for some time that the waggle dance’s directional information is not completely accurate,” Stroh explains. For food sources approximately 100 meters away, the waggle dance’s directional information can be off by approximately 30 degrees.
New research suggests that this dance’s lack of precision is not due to a lack of navigation skills. Instead, bees appear to be much more accurate when navigating to locations they already know.
“Our study showed that individual bees navigate to familiar destinations with much more precision. Even where flight paths vary the most, bees deviate from their individual routes by only a few degrees. Our results allow us to conclude that the inaccuracy of the waggle dance is not due to limited navigational abilities of the bees. Rather, individual animals are spatially oriented much more accurately than dance communication suggests,” says Stroh.
