The natural ability to glow a bright fluorescent color under ultraviolet light is one of the most astounding marvels ever observed within the animal kingdom. Fluorescence occurs when animals absorb light in one color and emit light in another color. Although fluorescence is currently believed by experts to be an extremely rare trait, it is common knowledge in the southwest US that scorpions glow a bright greenish yellow when exposed to UV light in the dark. In addition to scorpions, and a few insect species, puffin bills and chameleon bones have also been found to glow under UV light, but with the exception of opossums, no mammal has ever been found to possess the trait of fluorescence, until now, that is. Researchers have recently learned that three of North America’s flying squirrel species have fur that glows a bright pink color under UV light. This discovery is leading experts to believe that fluorescence may be more common in mammalian species than previously thought.
The trait of fluorescence in flying squirrels was discovered purely by accident. Paula Spaeth Anich, a biologist at Northland College, co-authored the recently published study on this phenomenon. However, the fluorescence of flying squirrels was brought to her attention by her colleague and fellow co-writer of the study, Jon Martin. Martin, a forestry professor, discovered squirrel fluorescens while he was searching for fluorescent species of fungi, lichens, plants and frogs within a Wisconsin forest at night. Martin momentarily shined his flashlight on a flying squirrel in a tree, and the rest is history. After sharing his finding with Anich, they both began to wonder if the fluorescence was a consequence of diet, or if it was a normal trait for flying squirrels. After examining all three flying squirrel species as well as ground squirrel species, it became clear that the ability to glow is shared by all flying squirrel species, but not ground squirrels. It is not yet known what purpose fluorescence serves in flying squirrels, but the trait is most likely a consequence of foraging during the dark of night, as most other animal species that are endowed with this trait are also nocturnal.
Do you think that it is probable that many more mammals have the ability to fluoresce, but have not yet been documented as having this ability?