Speaker 1: Welcome to brain Stuff from How Stuff Works, Hey, brain Stuff,
Speaker 1: Lauren Vogel bomb here. It's amazing what you can find
Speaker 1: if you shine a flashlight into your backyard trees. A
Speaker 1: biologists in Wisconsin have made a rather startling discovery that way,
Speaker 1: in part startling because it apparently hadn't been recorded until now.
Speaker 1: Three different species of flying squirrels, specifically Southern, Northern, and
Speaker 1: Humboldts flying squirrel which are found across North America and
Speaker 1: into Central America, sport light brown fur that, when spotlighted
Speaker 1: with ultra violet illumination, lights up a hot bubblegum pink.
Speaker 1: The phenomenon occurs on both the top and bottom surfaces
Speaker 1: of the flying squirrels, though it's the underside of a
Speaker 1: flying squirrel's carriage, including the flaps of skin that's spread
Speaker 1: out when the squirrel glides from tree to tree that
Speaker 1: really glows. Jonathan Martin, a biologist at Northland College in Ashland, Wisconsin,
Speaker 1: made the discovery in the forest one evening just by
Speaker 1: shining a UVY flashlight into the tree canopy. He was
Speaker 1: looking for lichens, which are certain types of frogs and
Speaker 1: flora that light up in UVY light. That's when he
Speaker 1: heard the chirp of a southern flying squirrel. As the
Speaker 1: squirrel glided by, he shined the UVY flashlight on it,
Speaker 1: and he saw a flash of fuchia. Martin and his
Speaker 1: colleagues soon found themselves examining the skins of flying squirrels
Speaker 1: at the Science Museum of Minnesota and the Field Museum
Speaker 1: in Chicago. They took photos of the skins under visible
Speaker 1: light and ultra violet light. All but one specimen of
Speaker 1: the gliders glowed a pink that has been variously compared
Speaker 1: to bubblegum, day glow, and licro from the nineteen eighties.
Speaker 1: The results of the study were published in the January
Speaker 1: twenty nineteen issue of the Journal of Mammalogy. The pink
Speaker 1: is caused, the researchers say, by the furs fluorescence, which
Speaker 1: is what happens when light is absorbed in one wavelength
Speaker 1: and emitted in another. You may remember an episode we
Speaker 1: did about how scorpions fluoresce bright green and ultraviolet light.
Speaker 1: Some birds also have this trait, some fish too. Few
Speaker 1: mammals do, though. Flying squirrels are nocturnal and are most
Speaker 1: active at dusk and dawn. No other squirrels in North
Speaker 1: America are known to possess this ability to fluoresce, including
Speaker 1: tree squirrels like the Eastern gray, though there are over
Speaker 1: two hundred and fifty squirrel species around the world, and
Speaker 1: to be fair, the researchers have not yet tested other
Speaker 1: species for the next question is what purpose could this
Speaker 1: fluorescence serve. Humans can't see ultraviolet wavelengths except under special lighting,
Speaker 1: but other animals can. One theory suggests the pink is
Speaker 1: used to confuse owls, which, as it turns out, also
Speaker 1: have undersides that fluoresce. A similar pink. Owls prey on
Speaker 1: flying squirrels, among other mammals. Perhaps the squirrels evolved to
Speaker 1: mimic owls so as not to be eaten by them.
Speaker 1: Another theory, which is already being challenged, is that the
Speaker 1: pink attracts potential mates. Flying squirrels have mating seasons, but
Speaker 1: their flamboyant fluorescence is available for view it in year round. Anyway,
Speaker 1: it's not even clear that squirrels can see in UV wavelengths. Ultimately,
Speaker 1: the researchers point out that age old impetus of science.
Speaker 1: This is proof of how much we don't know and
Speaker 1: still need to learn. The study concluded the ecological significance
Speaker 1: of this trait warrants further investigation. Today's episode was written
Speaker 1: by Jamie Allen and produced by Tyler Clang for iHeartMedia
Speaker 1: and How Stuff Works. For more on this and lots
Speaker 1: of other topics, visit our home planet, how stuff works
Speaker 1: dot com