Purr
From Wikipedia, the free encyclopedia
A purr is a sound made by all species of felids and is a part of cat communication. It varies between cats (for example by loudness and tone), and from species to species, but can be characterized as a tonal buzzing. Domestic cats purr in a frequency of 25 to 150 vibrations per second.
Although purring is commonly associated with felids, other animals such as raccoons purr. Other purring animals are: Guinea pigs in heat, rabbits, squirrels, ring-tailed lemurs, elephants while eating, and gorillas while eating.
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[edit] Purring mechanism
Despite being a universally recognized phenomenon, the mechanism by which cats purr is elusive. This is partly because the cat has no obvious anatomical feature unique to it that would be responsible. One hypothesis, backed 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, causing air vibrations during inhalation and exhalation[1]. Combined with the steady inhalation and exhalation of air as the cat breathes, a purring noise is produced with strong harmonics.[2]
It was, until recent times, believed that only the cats of the Felis genus could purr.[3] However, cats of the Panthera genus (Tiger, Lion, Jaguar and Leopard) also purr, but only when exhaling
[edit] Reasons for purring
Why cats purr is unknown. Cats often purr when being petted, becoming relaxed,[4][5][6] or when eating. Female cats are known to sometimes purr while giving birth.[7][8][5] Domestic cats have been reported to purr when injured, sick, in pain or dying.[4][8][5] Purring may be a signaling mechanism between mother cats and nursing kittens. One theory is that it is not a sign of showing love but attempting friendship, for example, when a cat is nervous (at a Vet perhaps) it may purr to avoid being hurt. [7][4] Another theory is that purring is a healing mechanism for repairing damage to, or maintainance of, bones, tendons, and muscles. [9]
[edit] References
- ^ K.M. Dyce, W.O. Sack and C.J.G. Wensing in Textbook of Veterinary Anatomy 3rd Ed. 2002, Saunders, Philadelphia; p156
- ^ How A Puma Purrs
- ^ Overview of Felidae
- ^ a b c "Why Do Cats ... ?". Pawprints and Purrs, Inc.. http://www.sniksnak.com/cathealth/whydo.html. Retrieved on 2008-08-06.
- ^ a b c "Solving The Cat's Purr Mystery using Accelerometers". Brüel & Kjær Magazine. http://www.bksv.com/NewsEvents/BruelKjaerMagazine/OtherArticles/TheCatsPurrMystery.aspx. Retrieved on 2008-08-06.
- ^ "The Cat's Remarkable Purr". isnare.com. http://www.isnare.com/?aid=195293&ca=Pets. Retrieved on 2008-08-06.
- ^ a b "The Remarkable Purr of a Cat - Why and How do Cats Purr?". cats.about.com. http://cats.about.com/cs/catmanagement101/a/why_cats_purr.htm. Retrieved on 2008-08-06.
- ^ a b "The Felid Purr: A bio-mechanical healing mechanism". http://animalvoice.com/catpur.htm. Retrieved on 2008-08-06.
- ^ "The Felid Purr: A bio-mechanical healing mechanism". Fauna Communications Research Institute. http://www.animalvoice.com/catpurrP.htm. Retrieved on 2009-04-06.
- Stogdale L, Delack JB. Feline purring. Compendium on Continuing Education for the Practicing Veterinarian 1985; 7: 551-553.
- Reprinted in: Voith VL, Borchelt PL (eds). Readings in Companion Animal Behavior. Trenton: Veterinary Learning Systems, 1996; 269-270.
