Cats have the power to glow in the dark, scientists discover

Cats glow in the dark when exposed to UV light
Cats glow in the dark when exposed to UV light - Gyeongsang National University/EPA

Cats always land on their feet, are seen as a symbol of good luck in some cultures and enjoy nine lives, but now feline folklore has received an extra boost as scientists have found they can even glow in the dark.

The domestic cat is one of 125 species that has been found to have fluorescent properties that illuminate it under UV light.

This ability has been noted in various animals in the past, including humans, but it was never known how widespread it was.

Scientists in Australia reviewed a museum’s collection of mammals to see how many glowed in the dark when a UV light was turned on and found 125 species had the ability.

The research found that all 27 orders - the level above genus - had members that possessed fluorescent properties.

“Fluorescence was most common and most intense among nocturnal species and those with terrestrial, arboreal and fossorial habits, with more of their body being more fluorescent,” the study authors said.

“It remains unclear if fluorescence has any specific biological role for mammals. It appears to be a ubiquitous property of unpigmented fur and skin but may function to make these areas appear brighter therefore enhance visual signalling, especially for nocturnal species.”

There are various forms of fluorescence but all involve the absorption of light and a low level emission, which often resembles a glow.

Role in nature ‘unknown’

The role of this phenomenon in nature remains unknown but is likely to help animals of the same species communicate. 

People and rabbits were the first mammals shown to have fluorescent properties when an academic paper in 1911 found human hair could emit light in the UV range.

Over the years a smattering of studies have identified specific individual species with fluorescent capabilities and provided unproven anecdotal evidence.

Kenny Travouillon, the acting curator of ornithology at Western Australian Museum, decided to test frozen and preserved mammal specimens from the collection to see how common the trait was.

Analysis of frozen and preserved mammal specimens were taken to Curtin University in Perth for analysis under a range of lights at different wavelengths.

Photographs and analysis revealed 125 species, 54 nocturnal and 71 diurnal, glowed under some form of UV light.

All types of mammals glow in the dark, including polar bears, zebras, wombats armadillos and the dwarf spinner dolphin
All types of mammals glow in the dark, including polar bears, zebras, wombats armadillos and the dwarf spinner dolphin

Yellow, white, and light brown fur was commonly fluorescent, and accounted for 107 species; 47 species had fluorescent bare skin, especially around the mouth and feet; and 68 had glowing claws.

The most fluorescent mammals were typically white or pale yellow, such as the polar bear, southern marsupial mole and an albino wallaby.

One dolphin, the dwarf spinner, was fluorescent, but only its teeth were seen to glow.

White fur, unsurprisingly, was the most common source of mammalian fluorescence, while blue, pink and orange was seen less commonly than expected.

“We report fluorescence for 125 mammal species, from half of all mammalian families and representing almost all clades in the mammalian phylogeny,” the scientists wrote

“The only major mammalian clade missing from our dataset is the lemurs… [and] we predict this clade will also contain fluorescent species.

“While the amount and location of fluorescence varied between species, all exhibited some form of apparent fluorescence. Areas of fluorescence included white and light fur, quills, whiskers, claws, teeth and some naked skin.”

The research was published in the journal Royal Society Open Science.