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Bumblebees have superfast colour vision

A new study has found bees' colour vision is five times faster than human's and among the fastest in the animal world.

Researchers belive the lightning-fast colour vision enables bees to zip through bushes and trees, escape predators, spot each other and otherwise deal with their world in fast forward.

The trick to their fast vision is how many 'snap shots' per second the colour-detecting cells in bumblebees' eyes take and send to their brains.

"The limiting factor is how fast the photo receptors can register a change," says bee vision researcher Dr Peter Skorupski of Queen Mary, University of London. "So we measured the speed directly from the receptor."

In a human eye the receptors are the cells in the retina at the back of the eye.

"When we see something it seems instantaneous," says Skorupski. "But there's a lot of processing going on under the bonnet. In our case there can be a delay of tenth of a second before you register what you are seeing."

Inspired by flies

The fastest vision known belongs to flies, but that is not colour vision, Skorupski explains.

"A lot of this has been worked out in flies," he says. "Our work was inspired by classic work on flies."

That work focused also on finding the connection between the speed of fly vision to the cost of having such amped-up sight, says Skorupski.

What he and his colleague Professor Lars Chittka wanted to know is whether there was a similar relationship between colour vision and the energy used by bees. In other words, do bees have fast colour vision and if so, do bees pay a price for the revved-up technicolours.

The first step was to measure the bee colour vision speed, which they have done and published in the Journal of Neuroscience.

Their bee experiments show that the colour receptors of bumbles were still slower than the colourless, or achromatic, receptors of bees. But, on the other hand, they are faster than human colour vision.

Good learners

Vision researcher Dr Fain Gordon of the University of California, Los Angeles says the finding is a solid piece of research that adds to other vision studies on toads, moths and other animals with a variety of faster, slower or just more sensitive vision than humans.

"There is no doubt that colour is important in bees' lives," says Skorupski. "Flying through dappled foliage, with rapidly changing lighting conditions, they are very good at learning colours and using colour cues to recognise their hives."

The next step, says Skorupski, will be to evaluate the cost to the bees - in terms of energy they consume.