Squeaking Up A Storm: Yes, That Mouse Is Singing

Jun 17, 2011
Originally published on June 20, 2011 1:40 pm

When you think of animals that sing, birds will certainly come to mind. Whales might, too. But mice? Or fish?

It turns out mice and fish do sing, although "vocalizations" might be a more technically correct way of describing the sounds they make.

Bret Pasch, a graduate student at the University of Florida, says there are plenty of mouse species that sing. "The more we search, the more we find that rodents and other small mammals produce vocalizations," he says.

The mice Pasch studies are called Alston's singing mice. They're easy to find if you're willing to spend days on end crawling around in the cloud forests of Latin America.

Pasch says it's mostly males that sing. Their song consists mainly of a rapidly repeated note, like a trill. To see which songs are most attractive to females, he changes the frequency and rate of this trill.

In one study that he reports in the current issue of Animal Behaviour, he put female mice in a mouse-sized arena with two speakers at opposite ends. Then he played them male songs with different note rates or trill rates, and watched what happened.

The females showed a clear preference.

"They approached the speakers that were emitting the faster trill. They approach that side more quickly, and spent more time there," says Pasch.

Pasch thinks the faster trillers probably have other qualities that make them better mate material.

Fish also make vocalizations that warn off intruders or attract mates. Andrew Bass, who studies sound production in fish at Cornell University, says fish make their sounds by vibrating the walls of an air-filled sack they have inside them called a swim bladder. And like singing mice, fish can modify their songs in a way that influences a female's behavior.

"The calls — attributes of the call — clearly contribute to a female's decision whether to go to one male or another," he says.

And since fish don't have access to genetic testing, a good song is probably the best way a male has to prove he's from good genetic stock and worthy of a female's attention.

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RENEE MONTAGNE, Host:

We know birds use their songs to attract mates and fend off competitors. You might be surprised to learn about some of the other animals of the nonhuman variety that use songs as part of the dating game. Well, at least NPR's Joe Palca was.

JOE PALCA: Unidentified Group: (Singing) Mr. Trouble never hangs around when he hears this mighty sound.

(SOUNDBITE OF "MIGHTY MOUSE" THEME SONG)

I: Unidentified Group: (Singing) That means that Mighty Mouse is on the way.

PALCA: But am I the only one that was surprised to learn that real mice sing, too?

BRET PASCH: It's not a well-known fact.

PALCA: Bret Pasch is a graduate student in animal behavior at the University of Florida.

PASCH: The more we search, the more we find that rodents and other small mammals produce vocalizations.

PALCA: The mice Pasch studies are called Alston's singing mice. They're easy to find if you're willing to spend days on end crawling around in the cloud forests of Latin America. And here's what they sound like.

ALISON RICHARDS: I can't hear anything.

PALCA: Maybe not a Grammy winner, but apparently capable of evoking a female mouse's interest. Pasch says it's mostly males that sing. In his studies, he changes the frequency and rate of this trill to see what has the most potent come- hither effect. One of those studies appears in the current issue of the journal Animal Behavior.

PASCH: In this study, we've manipulated the note rate.

PALCA: He put female mice in a mouse-sized arena with two speakers at opposite ends. Then he played them male songs with different note rates or trill rates and watched what happened. And by the way, to all male mice listening to this broadcast, females prefer the faster trill.

PASCH: Yeah, they approached the speakers that were emitting the faster trill. They approached that side more quickly and spent more time there.

PALCA: He says a lot of animals use songs to attract mates.

PASCH: Birds and frogs and even in fish.

PALCA: I'm sorry. Did you say fish?

PASCH: Yes, fish.

ANDREW BASS: Sound production in fishes has been known for decades.

PALCA: That's Andrew Bass. He studies sound production in fish at Cornell University.

BASS: You ever hear the names like drum fish or croakers?

PALCA: Yeah.

BASS: That's how they got their names, because of the sounds they make.

PALCA: Bass says fish make their sounds by vibrating the walls of an air-filled sack they have inside them called a swim bladder. And like singing mice, fish can modify their songs in a way that influences a female's behavior.

BASS: The calls - attributes of the call - clearly contribute to a female's decision whether to go to one male or the other.

PALCA: I suppose it shouldn't really be surprising the fish sing. Cartoons have proved that, too. Think Dory in "Finding Nemo."

(SOUNDBITE OF MOVIE, "FINDING NEMO")

ELLEN DEGENERES: (As Dory) (Singing) Just keep swimming, swimming, swimming. What do we do? We swim, swim, swim.

ALBERT BROOKS: (As Marlin) Dory, no singing.

DEGENERES: (As Dory) (Singing) Oh, ho, ho, ho...

PALCA: Joe Palca, NPR News, Washington.

DEGENERES: (As Dory) (Singing) When you want to swim you want to sing...

BROOKS: (As Marlin) See, I'm going to get stuck now with that song. Now it's in my head.

DEGENERES: (As Dory) Sorry.

(SOUNDBITE OF MUSIC)

MONTAGNE: You can see videos of singing mice at our website, npr.org.

(SOUNDBITE OF MUSIC)

MONTAGNE: This is NPR News. Transcript provided by NPR, Copyright NPR.