1 00:00:02,040 --> 00:00:07,120 Speaker 1: Welcome to brain Stuff from How Stuff Works, Hey, brain Stuff, 2 00:00:07,160 --> 00:00:10,200 Speaker 1: Lauren Vogel bomb here. It's amazing what you can find 3 00:00:10,240 --> 00:00:13,079 Speaker 1: if you shine a flashlight into your backyard trees. A 4 00:00:13,160 --> 00:00:16,919 Speaker 1: biologists in Wisconsin have made a rather startling discovery that way, 5 00:00:17,520 --> 00:00:21,040 Speaker 1: in part startling because it apparently hadn't been recorded until now. 6 00:00:21,880 --> 00:00:26,159 Speaker 1: Three different species of flying squirrels, specifically Southern, Northern, and 7 00:00:26,239 --> 00:00:29,280 Speaker 1: Humboldts flying squirrel which are found across North America and 8 00:00:29,320 --> 00:00:33,320 Speaker 1: into Central America, sport light brown fur that, when spotlighted 9 00:00:33,360 --> 00:00:37,760 Speaker 1: with ultra violet illumination, lights up a hot bubblegum pink. 10 00:00:39,000 --> 00:00:42,320 Speaker 1: The phenomenon occurs on both the top and bottom surfaces 11 00:00:42,360 --> 00:00:45,120 Speaker 1: of the flying squirrels, though it's the underside of a 12 00:00:45,120 --> 00:00:48,320 Speaker 1: flying squirrel's carriage, including the flaps of skin that's spread 13 00:00:48,320 --> 00:00:50,559 Speaker 1: out when the squirrel glides from tree to tree that 14 00:00:50,720 --> 00:00:56,480 Speaker 1: really glows. Jonathan Martin, a biologist at Northland College in Ashland, Wisconsin, 15 00:00:56,840 --> 00:00:59,240 Speaker 1: made the discovery in the forest one evening just by 16 00:00:59,240 --> 00:01:02,480 Speaker 1: shining a UVY flashlight into the tree canopy. He was 17 00:01:02,520 --> 00:01:05,479 Speaker 1: looking for lichens, which are certain types of frogs and 18 00:01:05,560 --> 00:01:08,840 Speaker 1: flora that light up in UVY light. That's when he 19 00:01:08,840 --> 00:01:11,920 Speaker 1: heard the chirp of a southern flying squirrel. As the 20 00:01:11,959 --> 00:01:14,880 Speaker 1: squirrel glided by, he shined the UVY flashlight on it, 21 00:01:15,040 --> 00:01:18,840 Speaker 1: and he saw a flash of fuchia. Martin and his 22 00:01:18,920 --> 00:01:22,039 Speaker 1: colleagues soon found themselves examining the skins of flying squirrels 23 00:01:22,040 --> 00:01:24,800 Speaker 1: at the Science Museum of Minnesota and the Field Museum 24 00:01:24,800 --> 00:01:28,160 Speaker 1: in Chicago. They took photos of the skins under visible 25 00:01:28,240 --> 00:01:31,480 Speaker 1: light and ultra violet light. All but one specimen of 26 00:01:31,480 --> 00:01:34,240 Speaker 1: the gliders glowed a pink that has been variously compared 27 00:01:34,280 --> 00:01:37,679 Speaker 1: to bubblegum, day glow, and licro from the nineteen eighties. 28 00:01:38,720 --> 00:01:41,760 Speaker 1: The results of the study were published in the January 29 00:01:40,959 --> 00:01:45,480 Speaker 1: twenty nineteen issue of the Journal of Mammalogy. The pink 30 00:01:45,640 --> 00:01:49,120 Speaker 1: is caused, the researchers say, by the furs fluorescence, which 31 00:01:49,160 --> 00:01:51,840 Speaker 1: is what happens when light is absorbed in one wavelength 32 00:01:51,840 --> 00:01:55,120 Speaker 1: and emitted in another. You may remember an episode we 33 00:01:55,160 --> 00:01:58,400 Speaker 1: did about how scorpions fluoresce bright green and ultraviolet light. 34 00:01:59,040 --> 00:02:02,680 Speaker 1: Some birds also have this trait, some fish too. Few 35 00:02:02,720 --> 00:02:07,240 Speaker 1: mammals do, though. Flying squirrels are nocturnal and are most 36 00:02:07,280 --> 00:02:10,520 Speaker 1: active at dusk and dawn. No other squirrels in North 37 00:02:10,560 --> 00:02:13,720 Speaker 1: America are known to possess this ability to fluoresce, including 38 00:02:13,760 --> 00:02:17,040 Speaker 1: tree squirrels like the Eastern gray, though there are over 39 00:02:17,080 --> 00:02:19,760 Speaker 1: two hundred and fifty squirrel species around the world, and 40 00:02:19,919 --> 00:02:22,519 Speaker 1: to be fair, the researchers have not yet tested other 41 00:02:22,560 --> 00:02:26,920 Speaker 1: species for the next question is what purpose could this 42 00:02:27,000 --> 00:02:31,840 Speaker 1: fluorescence serve. Humans can't see ultraviolet wavelengths except under special lighting, 43 00:02:32,120 --> 00:02:36,800 Speaker 1: but other animals can. One theory suggests the pink is 44 00:02:36,880 --> 00:02:40,239 Speaker 1: used to confuse owls, which, as it turns out, also 45 00:02:40,320 --> 00:02:44,240 Speaker 1: have undersides that fluoresce. A similar pink. Owls prey on 46 00:02:44,320 --> 00:02:47,760 Speaker 1: flying squirrels, among other mammals. Perhaps the squirrels evolved to 47 00:02:47,919 --> 00:02:51,200 Speaker 1: mimic owls so as not to be eaten by them. 48 00:02:51,240 --> 00:02:53,840 Speaker 1: Another theory, which is already being challenged, is that the 49 00:02:53,840 --> 00:02:57,799 Speaker 1: pink attracts potential mates. Flying squirrels have mating seasons, but 50 00:02:57,840 --> 00:03:01,800 Speaker 1: their flamboyant fluorescence is available for view it in year round. Anyway, 51 00:03:01,840 --> 00:03:06,480 Speaker 1: it's not even clear that squirrels can see in UV wavelengths. Ultimately, 52 00:03:06,600 --> 00:03:09,840 Speaker 1: the researchers point out that age old impetus of science. 53 00:03:10,400 --> 00:03:12,800 Speaker 1: This is proof of how much we don't know and 54 00:03:12,880 --> 00:03:16,880 Speaker 1: still need to learn. The study concluded the ecological significance 55 00:03:16,919 --> 00:03:25,640 Speaker 1: of this trait warrants further investigation. Today's episode was written 56 00:03:25,639 --> 00:03:28,399 Speaker 1: by Jamie Allen and produced by Tyler Clang for iHeartMedia 57 00:03:28,440 --> 00:03:30,680 Speaker 1: and How Stuff Works. For more on this and lots 58 00:03:30,680 --> 00:03:33,160 Speaker 1: of other topics, visit our home planet, how stuff works 59 00:03:33,200 --> 00:03:44,920 Speaker 1: dot com