11 July, 2018

Seeing colourful flowers like a bee

by Christian Verhoeven, Zong-Xin Ren and Klaus Lunau


Bees see the world different to us. A major difference between humans’ and bees’ colour vision is that the three types of  photoreceptors in humans are sensitive to blue, green and red light, whereas those in bees are sensitive to ultraviolet, blue and green light. We introduce a cheap and simple digital approach to reassemble colour images in bee view from UV-, blue- and green-photos. Photo editing allows to represent ultraviolet as blue, blue as green and green as red. Here we demonstrate the multiple advantages of this technique: Tiny details of flowers such as stamens, pollen grains and floral guides that escape spectrophotometric methods are visualized by false colour photography.
Visibility of colour changes in Forget-me-not
flowers for humans (top) and bees (bottom)
False colour images in bee view are more informative and easier to interpret as UV-photos and can be taken in the field. The minimal equipment needed includes a tripod, a modified digital camera, two colour filters, and a white standard. Testing this method yielded interesting findings including flowers displaying a blue bull’s eye and subtle colour changes. Moreover, false colour images let us see that flowers that are attractive for our eyes may be inconspicuous for bees and let us understand that showy flowers are adapted for bees’ eyes.

Read the scientific publication in JPE.