Wednesday, December 05, 2007

The nose knows

The next time your cat rubs its head against your leg, it may be more communication than affection. Kitty is probably marking you with its scent.

Cats rub against people and places to deposit saliva and secretions from three glands on the head. These deposits send a message to other cats: You are part of their territory. It may be like posting a “no trespassing” sign.

In the wild, creatures from lowly mice to lumbering bears and fleet-footed deer mark the trees and ground with semiochemicals. “Semio” is from Greek, meaning a “sign,” and mammalian signs are read with considerable interest. They often define territories, but their particular mixture of 50 or more compounds may even identify an individual animal, as a name or Social Security number identifies us.

In the case of deer, the meaning of scents can be quite complex, advertising a buck’s status in the herd, triggering the reproductive cycle in females and perhaps even stemming the sexual drive in bucks of lower status.

Most mammals have much better olfaction than humans – dogs and their wild kin have up to a million times more scent receptors than we do.

So remember when you take Fido for a walk: Those leaves and twigs he spends so much time sniffing could be his version of reading the local newspaper.

No comments: