Squirrel--the other other white meat

[novapsyche]

Squirrels emit 'silent scream'

While studying the little rodents, researchers noticed that some of them made faint whispering sounds, as if they had lost their voices.

But when these "silent screams" were processed by a bat detector, an abundance of ultrasound was detected.

The researchers believe the whispers might be "secret" alarm calls - that the squirrels' predators cannot hear.

[...] James Hare and his colleague David Wilson analysed the high-pitched calls, and found they were made in reaction to a threat; and elicited an alarm response in other squirrels.

Richardson's ground squirrels also make audible alarm calls, which seem to raise a more dramatic response in the "audience".

So the researchers speculate that whisper calls might indicate a slightly lower level of threat.

Comments

[inhumandecency.livejournal.com]

Rats also make an ultra[relative to humans]sonic noise, but they do it when they're playing or eating with close kin. Jaak Panksepp insists on referring to it as "laughter." Evidently they discovered it when his grad student meant to turn down the volume, and accidentally turned down the tape speed knob instead.

[droid-1.livejournal.com]

That's weird.
Also not fair, making sounds we can't hear.

[quility.livejournal.com]

Maybe the "silent" scream doesn't cause as much of a reaction in the "audience" b/c it means that the other squirrel is passed help. Like humans might not react noticeably to a cry for help if there was nothing we could do.

[viciouslamb.livejournal.com]

I also love this:

Nevada researcher Patricia Simonet of Sierra Nevada College in Lake Tahoe believes dogs make a specific noise during play that is distinctive from other sounds made during passive or aggressive confrontation. Simonet describes the sound as a breathy exhalation that sounds to a human ear like a dog's regular panting. However, when the frequency of the "laugh" was analysed, it was found to have a far broader range of frequencies than a regular pant.

The article also mentions ticklish rats. :)