Washington, D.C.-- Honeybees rely on visual cues to gauge the distance to a food source, and new information about their "optical odometers" may set the stage for pocket-sized surveillance technologies featuring insect vision, says the author of a 4 February Science article.
"Our study suggests that honeybees use cues based primarily on image motion to monitor flight distances of hundreds of meters in natural outdoor environments," reports Science author Mandyam V. Srinivasan.
Passing many visual landmarks-such as trees or flowers-makes the insects feel they have traveled a long way, just as telephone poles whizzing by a car window may enhance a passenger's sensation of speed, says Srinivasan, a professor with the Australian National University's (ANU) Centre for Visual Science within the Research School of Biological Sciences.
When foraging bees locate a meal more than 50 meters from the hive, it has long been known that they return to the colony and waggle their abdomens in the direction of the food source. The longer the dance, the farther the journey to food. If a meal is located closer than 50 meters, bees simply turn a few circles, performing what's called a "round dance."
In the late 1960s, other researchers had suggested that bees determine the distance to food based on the amount of energy expended during flight, Thomas Collett of the University of Sussex (U.K.) explains in a related Science "Perspectives" essay on Srinivasan's work. Then, in 1996, a different team discovered that bees flying between very tall buildings performed waggle dances suggesting they had flown half the distance signaled by bees traveling the same course near street level, presumably because "as the ground drops away, it doesn't seem to move as quickly by the bees' eyes," Srinivasan says.
Building on this earlier work, Srinivasan and his coauthors-Shaowu W. Zhang of ANU and Monika Altwein and Jüergen Tautz of
Contact: Ginger Pinholster
American Association for the Advancement of Science