Vibrissae Help Animals Feel their Environment

Question:

Dogs have warts on their jaw or under their chin or both. They seem to have inherited these from their wolf ancestors. What evolutionary purpose do you think these may play? Perhaps at one time they were identification marks?

 

Dr. Nichol:

Rather than warts, those mounds of skin around our dogs’ muzzles have an important function. The long, thick hairs that protrude from them, called vibrissae, help dogs, cats, rodents, and lots of other creatures sense movement and feel their way around in the dark. Even a slight draft can be detected by the blood-filled sinuses (mechanoreceptor) beneath the skin, giving the animal vital information about nearby prey or maybe that he/she is about to become prey.

 

Hunt or be hunted aren’t concerns for household pets but they still use their vibrissae to supplement information they gather with their noses, eyes, and ears. Some show dogs are subjected to trimming or even plucking of these highly sensitive feelers. It’s a very bad idea because it’s painful and diminishes their sense of security and well-being.

 

You could see these structures as canine beauty marks. In reality they are natural survival equipment.