Bumblebees’ Vision Enhances Through Movement, Confirms Study

When the bees move, their vision improves. Scientists at the University of Würzburg have now been able to prove this assumption.

It was already known from other insects that running or flying speeds up the processing of visual information in the brain. However, whether active behavior also has an effect on the processing of stimuli in the eye has not been investigated to date.

Using electrophysiological recordings — that is, the measurement and recording of electrical activity — a team of researchers from the Julius Maximilian University of Würzburg (JMU) has now determined the reaction speed of the bees’ eyes while the animals are sitting or walking. Scientists have been able to prove that walking bumblebees actually process visual information faster than those that don’t sit. They are now presenting their findings in the journal Proceedings of the Royal Society b.

Bumblebees see walking 20 percent faster

“The results are quite remarkable: walking bumblebees see 20 percent faster than their stationary characteristics,” says Professor Keram Pfeiffer of the Department of Zoology 2 at JMU.

Bees are able to effectively increase body temperature and thus speed up the course of biochemical processes. To do this, they shiver with their flight muscles. The simultaneous measurement of temperature and eye reaction speed suggests that the observed increase in reaction speed could be due to an increase in body temperature.

“We were able to prove that this was indeed the case by irradiating seated animals with a heat lamp and reproducing the results in this way,” explains Lisa Rother. The doctoral student is the first author of the study with Robin Mueller.

It was already known that higher light intensity enables faster vision. On further investigation, the researchers were able to determine how bright the light would have to be in order to achieve a similar increase as a result of motion. Result: the light intensity had to be increased by a factor of 14.

Follow-up experiments to gain deeper insights

More studies aim to clarify what benefit bees derive from this effect and whether they might actively use it.

According to Robin Mueller, there are basically two possible explanations. Possibility one: “The animals warm up their flight muscles while running so they can take off at any time. In this case, the observed increase in visual velocity would only be a beneficial side effect.”

The second possibility: the animals are actively warming up to process visual stimuli faster. This may have benefits simply because the visually perceived environment changes more quickly when moving. So bumblebees can also process these faster images more quickly. In flight, the bee’s head temperature rises to about 35°C. At the same time, the processing time of visual information in the eyes would then be half that of a seated position—which would be adequate for an even greater flood of information in flight.