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December 14, 2007

Friday Cat Blogging: The Huddle

Tonkpile 121407.jpg

Winter has truly arrived, with nighttime temperatures (air, not wind chill) below 0 F. The tribe really has a hard time in the cold weather -- they are truly heat-seeking devices. We play a little game with the heating pad that Susan left behind. It's about 24 x 8 " and they can all fit on it (barely) if they line up like sausages. When only one is on it, he/she stretches to take up the whole thing. The idea is to expose as much surface area as possible to the heat. Same goes for the radiator. MacKenzie especially loves to stretch out on top of the warm radiator, exposing every square inch possible to the heat.

Anyway, the game ... The heating pad has an automatic timer that turns it off after 30 or 60 minutes (you can set it.) Often, when I'm working in my study, I'll turn the heating pad on for them in the bedroom. About 10 minutes after it turns off and cools down, MacKenzie will come padding down to my study and jump in my lap, then want to be held like a baby on my shoulder. Within 30 seconds, Shadow will be bopping in, wanting the same. And of course, they both want to occupy the same space (on me) at the same time. It's hard to do much else with 2 cats on my shoulder, so usually I carry them back to the bedroom and turn the heating pad on again.

For several years, I have used their heating pad behavior in my human development class as an example of classical conditioning. The heating pad makes a little "ding" sound when I turn it on. The cats have learned, through association, that "ding" means "the heating pad is warming up - time to jump on." And they do. But it just hit me that they have conditioned me (instrumental conditioning) to carry them back to the heating pad -- since every time both of them pile on while I'm trying to work, I carry them back and turn the heating pad on again, thus rewarding their "jumping on" behavior. They didn't want me - they just wanted me to turn the heating pad on again! (Although who knows the inscrutable ways of cats...) Another example for the next time I teach learning theory!

Tonks have no respect for personal space. Shadow is A+ in that domain. This morning, while trying to sleep at least a few minutes past 6:00 a.m., he decided to lay on my face -- I guess my face is warm and he figured it might be as good as a heating pad or a radiator. But the fascinating thing was that he positioned his purr-er right over my ear. He makes quite a racket! So I consulted Wikipedia to find out how cats purr. Here's what it said:

"A purr is a sound made by some species of felines and is a part of cat communication. It varies in detail from cat to cat (e.g., loudness, tone, etc.), and from species to species, but can be characterized as a sort of tonal buzzing. All domestic cats purr in a frequency range of 22.4 to 30.2 hertz. Some cats purr so strongly that their entire bodies vibrate; conversely, other cats may purr so quietly that the only indication is a vibration felt when touching the cat's throat. ... [Shadow's is definitely a full-body purr.]

"Despite being a universally recognized phenomenon, the exact mechanism by which the cat purrs has been frustratingly elusive for scientists. This is partly because the cat has no obvious anatomical feature unique to it that would be responsible and may also be partly because a cat placed in a laboratory for examination is unlikely to make the noise.

"One hypothesis, backed up by electromyographic studies, is that cats produce the purring noise by fast twitching of the muscles in their larynx, which rapidly dilate and constrict the glottis, thus causing vibrations in the air both during inhalation and exhalation[1]. There is also some contribution from the diaphragm. A timing mechanism in the brain sends neural messages to the muscles in the larynx, rhythmically opening and closing the air passage approximately 25 times per second.[2] Combined with the steady inhalation and exhalation of air as the cat breathes, a purring noise is produced with strong harmonics.[3]"

Fascinating! The author is certainly right that cats don't purr on demand. So maybe I can contribute my good fortune (of being a target of purring) to purring research -- I'll have to think about that. Woops - MacKenzie just walked in the door and jumped on my shoulder. Must be time to turn the heating pad on again.

Posted by hgroteva at December 14, 2007 11:03 PM | Cats

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