Fear The Squirrel August 13, 2007Posted by Mrs Weird Scientist in Animals, Evolution, Rattlesnakes, Squirrels, Technology, Think About It.
That cute, furry squirrel you see scurrying around actually has an effective defense mechanism in place to ward against predators. But worry not about crossing a squirrel’s path, because it’s not just any predators. It’s rattlesnakes! Even more interesting is that it’s an invisible weapon. Well, not too invisible given that modern technology allows us to view this very special weapon against rattlesnakes. So just what is this special weapon? It’s heat! A hot tail, that is.
Watch Out For The Tail
Californian ground squirrels heat up their tails and then swish them at the rattlesnakes. The rattlesnake has a cool infrared sensing organ that detects this heat and movement, which then throws the rattlesnake off guard. Other squirrels can’t see this heat, but the rattlesnakes sure can.
It was already known that Californian ground squirrels waved their tails at rattlesnakes. However, graduate student Aaron Rundus and his supervisor Donald Owings of the University of California, Davis, were curious to learn more about how these two creatures interact. So, Rundus used an infrared camera and set off to investigate the battles between rattlesnakes and squirrels. He captured footage of the squirrel’s tail in action after it was confronted by a rattlesnake.
A really interesting thing to note is that when the squirrel was confronted by a gopher snake, its tail did not heat up, although it did swish around. Gopher snakes don’t have the infrared detection organ that rattlesnakes use to detect heat.
Credit: Both videos are from New Scientist.
Is The Squirrel Alone?
Another fascinating part of this research is that other animals may use similar weapons to fend off predators. It could only be a matter of time now until scientists find out about other animals who use heat – maybe even through more sophisticated measures – to protect themselves.