Viewport width =
March 12, 2012 | by  | in Opinion |
Share on FacebookShare on Google+Pin on PinterestTweet about this on Twitter

Science: What’s It Up To?

Doing It For Bats

Aside from being associated with one of the most badass vigilantes ever, bats mostly exist under the radar, and are rarely included in the average person’s Top Five favourite animals. However, these night-time marauders have a lot going on, and you should seriously consider rethinking your list.

Bats have adapted to a nocturnal lifestyle to avoid the wrath of fierce daytime predators, and also to take advantage of the plethora of tasty night time insects. But how do they manage to hunt moving targets with such grace and such finesse? Instead of relying on their eyes, they use echolocation to make their way in the darkness.

Echolocation is a way of interpreting ones surroundings using sound rather than light. By sending pulses of ultrasonic sound, and comparing the outgoing sound with the returning echoes, the brain and auditory nervous system can produce detailed images of the bat’s surroundings. This allows bats to detect, localize and even classify their prey in complete darkness.

If we listen to the clicks of the common brown bat (Myotis), we see that it has an average of ten per second. This means that the image of its surroundings is being updated ten times a second. For us, this would be like having a strobe light on constantly (without the epilepsy), fine for some ordinary purposes, but not suitable for quick movements like juggling chainsaws or catching fleeing insects.

It turns out that ten pulses per second is just the sampling rate of the bat as it is on a routine cruising flight. When it detects dinner, the pulse rate increases dramatically up to 200 per second as it moves in on its target. Now, rather than seeing a series of updated images, the bat instead has a constantly updated feed, enabling it to perform swift and delicate movements as it hunts. However, these high speed pulses are a large drain of energy, so are only used when needed. When the insect has been caught the bat drops its rate back down to cruise.

In 1940, when Donald Griffin and Robert Galambos first presented their discovery of echolocation in bats, they were challenged by military scientists. Radar and sonar (less sophisticated man made versions of echolocation) were still highly classified developments in military technology, and the notion that bats might do something remotely analogous to the latest triumphs in military engineering struck most people as not only implausible, but emotionally repugnant. However, once again it was a case of human engineers developing breakthrough technology, only to find that evolution perfected it long ago. Classic.

If bats aren’t in your Top five then consider adding them, and if you don’t have a Top five then make one.

Share on FacebookShare on Google+Pin on PinterestTweet about this on Twitter

About the Author ()

Comments are closed.

Recent posts

  1. An (im)possible dream: Living Wage for Vic Books
  2. Salient and VUW tussle over Official Information Act requests
  3. One Ocean
  4. Orphanage voluntourism a harmful exercise
  5. Interview with Grayson Gilmour
  6. Political Round Up
  7. A Town Like Alice — Nevil Shute
  8. Presidential Address
  9. Do You Ever Feel Like a Plastic Bag?
  10. Sport
1

Editor's Pick

In Which a Boy Leaves

: - SPONSORED - I’ve always been a fairly lucky kid. I essentially lucked out at birth, being born white, male, heterosexual, to a well off family. My life was never going to be particularly hard. And so my tale begins, with another stroke of sheer luck. After my girlfriend sugge