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 when touching the cat's throat. In addition, some are able to meow or hiss without interrupting the purring sound. ( Listen (help· info) to a domestic cat purring) Sound is a disturbance of mechanical energy that propagates through matter as a wave. ... “Feline” redirects here. ... A yawning cat Cat communication consists of a range of methods with which cats communicate with humans, other cats, and other animals. ... Binomial name Felis catus Linnaeus, 1758 Synonyms Felis lybica invalid junior synonym The cat (or domestic cat, house cat) is a small carnivorous mammal. ... FreQuency is a music video game developed by Harmonix and published by SCEI. It was released in November 2001. ... MHZ redirects here. ... Image File history File links Purr. ... Image File history File links Purr. ...

How felines 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 theory is that cats produce the purring noise by vibrating their larynx, or voice box, in a particular manner. A timing mechanism in the brain sends neural messages to a muscle in the larynx, rhythmically opening and closing the air passage approximately 25 times per second.^[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 once believed that only the cats of the Felis genus could purr; some older texts may still say this.^[3] In fact, all cats are able to purr. However, the entire Panthera genus is able to purr only while exhaling. Cats that are not members of the Panthera, even larger ones such as the cheetah, purr.^[4]. The larynx (plural larynges), colloquially known as the voicebox, is an organ in the neck of mammals involved in protection of the trachea and sound production. ... In acoustics and telecommunication, the harmonic of a wave is a component frequency of the signal that is an integral multiple of the fundamental frequency. ... Felis is a genus of cats in the family Felidae. ... For other uses, see Genus (disambiguation). ... Type species Felis pardus Linnaeus, 1758 Panthera is a genus of the family Felidae (the cats), which contains four well-known living species: the Lion, the Tiger, the Jaguar, and the Leopard. ... This article is about the animal. ...

Historical theories

One theory held that purring involved blood hitting the aorta. Another possibility was that another area of soft tissue or muscular tissue in the neck or torso (e.g., the diaphragm) similarly vibrates. Another held that purring might have been caused by the vibrations of the hyoid apparatus, a series of small bones connecting the skull and the larynx that nominally serves to support the tongue. Yet another theory held that cats might possess a special purring organ, though none was found. Human blood smear: a - erythrocytes; b - neutrophil; c - eosinophil; d - lymphocyte. ... The aorta (generally pronounced or ay-orta) is the largest artery in the human body, originating from the left ventricle of the heart and bringing oxygenated blood to all parts of the body in the systemic circulation. ...

Why felines purr

Above all, the purr is probably the cat's way of communicating to others (cats and humans) that it is in the mood to be sociable. The purring sound is frequently made at the same time that other 'sociable' signals are made, e.g. erect tail, slightly closed "contented" eyes. Naturally, in most situations, this will also be when the cat is feeling contented, but it need not necessarily be so. Humans usually interpret the purring of a domestic cat as an expression of some type of friendliness or contentment. This assumption is based on the observation that cats often (though not always) purr when being stroked by humans.

It is, however, not entirely clear to scientists whether this really is one of the cat's reasons for making the sound; it is well-established that a cat also purrs when it is uneasy, nervous or in great pain, perhaps to comfort itself or to express submission. Other theories suggest that a cat purrs when it wants, needs, or is receiving attention, whether it be affection or medical treatment. When cats purr while also lightly clawing the ground it may mean they are trying to relieve stress or comfort themselves.^{[citation needed]} “Hurting” redirects here. ...

An intriguing possibility postulated by Roy Feinson in The Secret Language of Names (The Overlook Press, 2004) suggests that the question is best answered by asking 'when do cats not purr?' He writes "...a clowder of wildcats relax under a tree engaging in gentle purring when one of the cats spots a rabbit. The cat abruptly stops purring and the sudden silence immediately puts the other cats on alert without any audible or motion signal that might have alerted the prey. Thus, maintaining a low-energy purr at times of well-being allows the absence of that sound to become a communication device."

The theory is strengthened by the fact that cats tend not to purr when alone.

Ethologist Paul Leyhousen, in his book Cat Behavior, interprets purring as a signal meaning "I am not a threat" to explain the otherwise differing circumstances that elicit the sound. Ethology is the scientific study of animal behaviour (particularly of social animals such as primates and canids), and is a branch of zoology. ...

Purring as communication between cats

It is not quite clear how and when purring is used between cats themselves. It is likely that purring is a cat's way of communicating to other cats that it is in a sociable mood, or that it has no aggressive intent toward others.

Purring may also be a signaling mechanism between mother cats and nursing kittens. Female cats are known to purr while giving birth. Kittens purr while nursing, presumably as an "all's well" signal to their mother. An infant breastfeeding International Breastfeeding Symbol (Matt Daigle, Mothering magazine contest winner 2006) Breastfeeding is the feeding of an infant or young child with milk from a womans breasts. ... Kitten at six weeks. ... Parturition redirects here. ...

References

1. ^ Purring for bone strength and healing
2. ^ How A Puma Purrs
3. ^ Overview of Felidae
4. ^ Cheetahs can purr

• 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.

External links

1. Why and how do cats purr?
2. Why do Cats Purr?