Thursday's Tidbit

Reindeer: they've got a pretty big night coming up. Aside from pulling Santa's sleigh, did you know that they are thought to be the only mammals that can see ultraviolet light? A 2011study found that reindeer can see light with wavelengths as low as 320 nm, far outside of the human threshold of 400 nm. This ability may help them to survive in the Arctic - many objects that blend into the landscape in visible light, such as urine and fur, create sharp contrasts in ultraviolet light.  Also, male reindeer loose their antlers in the winter, so Santa's reindeer must be female. Now you know.  

Image via, info.