Three animals under UV light: a kangaroo glowing red, a possum glowing blue and pink, and a cockatoo glowing blue with a yellow crest, all set against a black background.A kangaroo, a quoll, and a cockatoo emitting biofluorescence when put under a UV flash.

A chance encounter with a family of adorable quolls has led one photographer to explore a hidden world of light that some animals emit when ultraviolet light is shone on them, known as biofluorescence.

Ben Alldridge discovered that the quolls — marsupials roughly the size of a housecat — were biofluorescent while on a camping trip that he happened to have brought his specialized camera equipment on.

From his home in Tasmania, Australia, Alldridge tells PetaPixel that his interest in biofluorescence began years ago when he was growing coral, experimenting with blue and UV light to optimize growth rates. “It sort of grew from there,” he says.

A small spotted marsupial with blue glowing spots on its fur is standing on a rock at night, illuminated by ultraviolet light against a dark background.An eastern quoll glowing underneath Alldridge’s UV flash.
Below, a comparison of visible light and UV light. Alldridge has since figured out how to get rid of the AF assist beam marks.


After his encounter with the quolls, Alldridge has discovered that Tasmanian devils are also biofluorescent, albeit under a different spectrum, as well as kangaroos, wombats, cockatoos, and echidnas. Until he uses UV light, he has no idea which species are biofluorescent and which aren’t.

“At this stage, there is a very small canon on it. We know of several hundred species in the ocean that do it. We know of plants and fungi that do it. We know quite a lot about invertebrates that are doing it; scorpions and spiders. But mammals? Essentially nothing. It’s totally new ground.”

A close-up of an echidna with spiky fur, illuminated in blue light against a pitch-black background.Echidna A wombat is illuminated by vibrant blue and pink lighting, standing out against a dark background. The light highlights the fur and facial features of the animal.Wombat A bird with bright, neon-yellow stripes is perched on a wire shelf, illuminated under blacklight in an otherwise dark environment. The bird's face and beak are also highlighted by the light.Parrot

A parrot with blue feathers is illuminated by a dramatic blue and purple light in a dark setting, highlighting the texture of its plumage against a barely visible background.

A kangaroo is illuminated by blue and red lights against a black background, highlighting its glowing blue eyes, ears, and legs.Kangaroo What the Heck is Biofluorescence?

Many will be familiar with bioluminescence found in fireflies, glowworms, and the ocean. Bioluminescence effectively conjures its own light, whereas biofluorescence only comes out underneath certain lights — UV and blue — and a biofluorescent animal will respond with a specific corresponding color that glows.

To bring out this biofluorescence, Alldridge has a specialist type of UV flash which looks like a normal speedlight except when it fires, humans can’t see the light since ultraviolet is outside of the visible light spectrum.

“They’re harvesting that little bit of energy, whether it be as protection, encouraging other animals to come and interact with them, or attracting prey — we’re not actually sure why they’re doing it. But they are taking that little portion of light and then putting out totally different colors.”

A lighthouse glows beside a small house on rocky terrain under a vibrant night sky, illuminated with stars, the Milky Way, and purple-blue auroras. The rocks and ground reflect blue and orange hues.Alldridge is an accomplished landscape photographer and has incorporated his biofluorescent skillset into some of his vista work.

A brightly lit lighthouse stands behind a white building at dusk. In the foreground, rocky stones glow with blue and orange bioluminescence, creating a mystical effect under a starry sky.

Tree trunks illuminated with bright yellow and blue lights stand out against a dark background at night, creating a glowing, surreal forest scene.

Colorful rocks with bright orange, yellow, and blue lichen by a rocky shoreline under a vibrant night sky with visible stars and a glowing moon or sun near the horizon, casting a surreal light on the scene.

Alldridge is in a very small club of photographers capturing animals in this way. He says a “few high-end Nat Geo” photographers have done it but he has the largest collection of biofluorescent photos of mammals in the world.

“It’s been very much the domain of people that have had access to really sensitive cameras just simply because they’re such a small amount of light that you’re dealing with,” he adds.

A parrot with vibrant blue feathers and a glowing yellow crest stands against a black background, illuminated by dramatic lighting.

Alldridge has shot most of his photos on the island of Tasmania, but he hopes to travel more as he continues his “voyage of discovery.”

“It’s different for each individual species,” Alldridge says of his ongoing research. “There are some things where it seems like it’s a relatively logical leap. In birds we know that they’re using it for signaling, for mating cues, and those sorts of stuff. Certain plants and fungi are using it for pollination purposes. But for these guys [mammals], your guess is as good as anybody’s. For all we know, they’re not even actually aware that they’re doing it.”

More of Alldridge’s work can be found on his website and Instagram.

Image credits: Photographs by Ben Alldridge