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Airdate: Nov 06, 2015
Scientist: Rolf Mueller

Bats - The Nose Knows

Bats - The Nose Knows
Many bats emit sounds through a "nose-leaf", which is like a little megaphone that surrounds the nostrils.

Bats - The Nose Knows

ambience: Bats
Bats hunt and find their way in the dark using a sophisticated sonar system that scientists marvel at. In some ways, bats may be finding their way by their nose. I'm Jim Metzner and this is the Pulse of the Planet.

Mueller: Bats produce ultrasound the way we produce speech. They have a voice box in their throat, and they use that to produce the sounds, but then the way they come out is through different avenues. One is through the mouth, just like we do it with speech, but the most sophisticated bats, they don't speak through their mouth. They speak through their nose, through their nostrils.

Rolf Mueller is an Associate Professor of Mechanical Engineering at Virginia Tech.

Mueller : Those bats that emit their sound through the nostrils, they have this nose-leaf, which is like a little megaphone that surrounds the nostrils. So, this is quite a sophisticated instrument that the bat uses to emit the sound.

It's called a nose-leaf because in some bats it closely resembles a leaf-like structure.

Mueller: The nose-leaf works very similar to an ear. They are on opposite ends of the channel. That is like a communication channel that starts with the nostrils, and then, it goes out into the environment, and then, it comes back through the ears. So, you have the two places where you, as a bat can manipulate this channel is when the sound exits and when the sound enters.
There's a systematic difference between what nose-leaves do and what ears do, and bats seem to do one thing when they emit and another thing when they receive. We are not exactly sure what the differences are, and we are also not sure how the animal uses them and why it has to have them.

As with so many things in science, the more you know, the more questions you have. We'll hear more on bats in future programs. I'm Jim Metzner and this is the Pulse of the Planet.