Animal communication is always fascinating. Here are some theories I found about why cats 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, combined with the experience that human children tend to enjoy stroking by their parents and interpret it as a gesture of affection. Consequently, most humans enjoy listening to or holding a purring cat.
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. Purring may also reduce pain, help a wounded cat to heal, or even help to keep a cat's bones strong. When cats purr while also lightly clawing the ground it may mean they are trying to relieve stress or comfort themselves. An example is when a female cat is nursing kittens; as humans may find with children, cats may also become stressed from the attention of their young and therefore start to purr and lightly claw the ground. This may also be associated with "kneading" behavior, in which the kittens' pawing helps release milk from the nursing mother's teats.
Trackposted to Pet's Garden Blog, The Pink Flamingo, Blog @ MoreWhat.com, The Random Yak, Right Celebrity, and The Yankee Sailor, thanks to Linkfest Haven Deluxe.
cat, animal communication