Mysteries of cats revealed

Cats remain mysterious beings. That's part of their charm. Here are some revealing facts about the fascinating felines sharing our homes.

Purring: Cats purr at the same frequency as an idling diesel engine, about 26 cycles per second. According to Leslie A. Lyons of the School of Veterinary Medicine at the University of California, Davis, cats purr to communicate pain as well as pleasure. Purring enables self-healing. Purring may help prevent or lessen dysplasia and osteoporotic conditions common in dogs. Cats with broken bones often heal remarkably quickly. A veterinary saying goes "if you put all the bones of a cat in a room, the cat will reassemble itself"

Marking: Cats sometimes mark their humans. They have glands around their lips and chin which secrete a scent known only to cats when rubbed on a person. Touching their nose or forehead to a person is a sign of affection.

Scratching and Kneading: Cats "shed" their claw covers by stretching and clawing surfaces. Individual cats prefer vertical or horizontal scratching. Cats have scent glands in the pads on their paws. When they knead, some of their unique scent is released as a territorial marker. Kneading may reflect wild cat behavior, patting down grass or leaves to make a bed for sleeping or birthing.

Falling: "A cat always lands on its feet" refers to the fact that when falling, the fluid in the inner ear shifts and the cat rotates its head until it equalizes and the fluid is level. The flexible feline body automatically shifts to follow the head, and a lucky cat can land on its feet.

Vision: A cat's field of vision is about 186 degrees. Pupils dilate from emotion as well as from light conditions. Scientists now know that cats are not color blind.

Whiskers: A cat's whiskers are a measuring tool, about body width. They are extra strong hairs called vibrissae or tactile hairs, They appear above the eyebrows, back on the cheeks, and shorter ones grow on the backs of the front legs. Whiskers are at least twice as thick as the cat's ordinary hair, and super sensitive.

Talking: French researchers identified a feline vocal range of up to 60 notes. Cats who are spoken to regularly "speak" back. Chirping, observed when an indoor cat watches birds through a window, is thought to be a deliberate imitation of bird sounds to attract prey.

Agility: Cats lack a true collarbone so generally they can squeeze their bodies through space they can get their heads through. Lack of a shoulder blade allows freedom of foreleg movement to turn in almost any direction. A cat has around 290 bones, 30 vertebrae, and 517 separate muscles. About 10 percent of a cat's bones are in its tail, critical for balance.

Reproduction: Unfortunately, cats can reproduce several times a year, and kittens mature quickly. Cat euthanasia due to feline overpopulation is a tragedy which can be prevented. Spay-neuter surgeries are safe and financial assistance is available. "Fixed" cats live longer and are protected from some cancers. Contact your county animal shelter about low-cost spay-neuter programs in your community.

• Dawn Armstrong is the executive director of the Lake Tahoe Humane Society and SPCA.