OBSERVATORY. (Science Desk)(new research on honeybees use of vector navigation to return home)(includes other science news) Henry Fountain.

Full Text: COPYRIGHT 2003 The New York Times Company

Supernavigator's Secret

Honeybees can go home again, and again, and again. Their ability to return directly to the hive after a rambling flight in pursuit of food is remarkable, although exactly how they accomplish this has been unclear.

The most reasonable explanation is that, like some other insects, they use vector navigation, constantly calculating the required direction of homeward travel from their movements during foraging.

Using radar, scientists from Britain and Germany have now provided strong evidence that honeybees navigate this way. The researchers outfitted honeybees with tiny transponders so they could be tracked.

In a large mown field outside a German village, they allowed the bees to reach a feeding station. But before the bees left to return to the hive, the researchers moved them to another location in the field. A paper describing the work was published online in The Proceedings of the Royal Society of Britain.

The researchers found that the displaced bees still flew in the direction that would have taken them home from the feeding station. In other words, they used the navigational calculations they had made while foraging. Some even completed the entire length of what would have been the return flight before starting to search for their hives.

The bees appeared to be on automatic pilot; they ignored large artificial landscape features placed in the return path and compensated for wind drift. Previous studies have shown that bees measure distance traveled using the flow of images of the ground across their retinas. The researchers suggest that bees are using this tool, plus their ability to orient themselves according to the sun's angle in the sky, to make their return journeys.