On a dark and misty night in the countryside, amidst the calls of a tawny owl, I find myself captivated, gently caressing a slug. Nearby, Jeremy Buxton, a farmer, exclaims with delight, “Oooh, an earthworm! Oh, wow.”
As I touch the brown slug, it emits brilliant fluorescent yellow slime, while the earthworm reveals twin tracks of turquoise on its belly. This may appear to be an experiment with psychedelic mushrooms, but it’s actually a novel way of experiencing the nocturnal world: using ultraviolet (UV) torches to unveil the natural biofluorescence of animals, plants, and fungi.
David Atthowe, a passionate naturalist and walker who conducts guided night strolls with UV torches, notes, “We’re in a minority of animals that can’t see biofluorescence. It’s a form of communication. We’re just not aware of it.”
This particular walk takes place in the wildlife-friendly fields of Buxton’s farm in Booton, Norfolk, and it’s a revelation. Unlike bioluminescence, where organisms produce visible light through a chemical reaction, biofluorescence is the absorption of light by living organisms, which they emit as vibrant blues, greens, reds, and yellows. Ultraviolet light has wavelengths shorter than those detected by the human eye, but UV torches allow us to see it.
The scientific community is currently on a journey of discovery regarding biofluorescent communication. While it has long been documented among marine organisms like sharks, it was only recently discovered that many mammals exhibit biofluorescence. North American flying squirrels, for example, shine brilliantly in pink, and recent Australian research found that 86% of 125 studied mammals had fur that glowed under UV light.
Atthowe stumbled upon this phenomenon through a TED Talk and has since imported UV torches from China to explore various habitats across Britain. This summer, he launched night walks for small groups in East Anglia.
As Atthowe says, “It’s become this incredible journey of discovery.” He shares some of his favorite findings, such as fluorescent hedgehogs and moles, stating, “Not many black animals fluoresce, but I found a dead mole, and its fur was blue. And Sonic the hedgehog is totally real! Hedgehogs go blue as well. That’s exciting.”
During the night walk, lichen that appears yellow-grey by day is revealed as brilliant orange, and algae on fence posts, unnoticed in daylight, becomes vivid red. Even woodlice scurrying along a branch emit a luminous blue glow. Grass seeds take on an aquamarine hue.
One of the most surprising discoveries is that nettles in sunny spots remain green, while those in shadier areas have leaves of vivid red.
Buxton, with a keen eye for nature, spots a moth on an oak tree trunk. In normal white light, it appears grey-brown, but under UV light, it shimmers with subtle purple and pink. Lepidopterists have recently found that certain butterfly chrysalises, which are well-camouflaged in daylight, glow brightly under UV light, making it easier to scientifically monitor species like the purple emperor.
This enchanting exploration of biofluorescent nature transforms the way we perceive the hidden beauty of the natural world, revealing a kaleidoscope of colors that is usually invisible to the human eye.