In a spectacular finding, scientists have uncovered that North American flying squirrels glow in the dark. The peculiar critters don’t just flash any type of color – they actually glow in a hot-pink shade when observed under UV light, Science Daily is reporting.
The incredible discovery is detailed in a study recently published in the Journal of Mammalogy, which announced to the world that the North American flying squirrel is secretly fluorescent, becoming pink at night.
The secret of the pink flying squirrel was outed completely by chance. According to CNET, the first person to ever stumble upon a fluorescent North American flying squirrel was Jon Martin, a professor in the forestry department at Wisconsin’s Northland College. The professor was studying the fluorescence of several plant species, including mosses and lichens. One night, he armed himself with an ultraviolet flashlight and stepped out for an exploratory survey to scan his backyard for glowing vegetation.
During his nocturnal investigation, Martin serendipitously came across a fluorescent squirrel that happened to stop at his bird feeder. The scientist was surprised to find that the creature gave off a vivid flash of hot-pink, visible only under the UV light.
That first encounter occurred in the spring of 2017. Soon afterward, Martin enlisted the help of Northland student Allison Kohler to study the matter at length.
The team examined more than 100 flying squirrel specimens from various museums across America. Their research included the specimens found in the decade-old collections of stuffed squirrels preserved at the Minnesota Science Museum and the Field Museum of Natural History in Chicago.
“Some specimens were extremely vibrant pink, while one actually didn’t fluoresce at all. All but this one did fluoresce, however, in some intensity or another,” said Kohler, who is now a graduate student in the Texas A&M University wildlife and fisheries department in College Station.
In order to verify their findings, the biologists also looked at five live specimens of flying squirrel. Their efforts revealed that all three species of North American flying squirrel – which include the northern flying squirrel (Glaucomys sabrinus), the southern flying squirrel (Glaucomys volans), and the Humboldt’s flying squirrel (Glaucomys oregonensis) – sported a pink flash under UV light.
"Scientists in Wisconsin have just discovered that flying squirrels, including two specimens from B.C., are vividly fluorescent under UV light." https://t.co/DEDwXCFmRt— Ruby Lake Lagoon (@RubyLakeLagoon) February 6, 2019
While the reason for the flying squirrels’ nocturnal pink flashes has largely remained a mystery, the scientists do have a few theories.
“They could be communicating with members of their own species by showing off their fluorescence to each other, or it might be a sort of mating display.”
Another hypothesis is that the tiny forest dwellers could be using their bright pink fluorescence to avoid predators — “by blending in or dealing with their potentially ultraviolet-saturated environments,” explained Kohler.
What is certain is that no other species of squirrel glow pink in the dark. The team compared the flying species to other types of squirrels, such as the American red squirrel and gray squirrel, and uncovered that only flying squirrels shine pink under UV light.
According to the National Geographic, the only other mammals known to have fluorescent fur are about two dozen species of opossum.