The sense of smell is a wolf's essential sense. Wolves use their nose to identify individuals and species and to determine age, gender, diet, social rank, emotional state, and breeding condition, according to Fred Harrington and Cheryl Asa in "Wolves: Behavior, Ecology, and Conservation." "To have a wolf's nose for only one day would surely reveal a whole new world," they add.
To estimate just how strong a wolf's sense of smell is, the author's compare wolves with dogs, a much more studied animal. They assume that a wolf's sense of smell is at least as strong as that of a dog. And dogs, they say, "are a hundred to millions of times more sensitive than humans in perceiving odors."
The odors that wolves perceive so well are honest communication that can't be faked, since a wolf has little control over the odors it leaves. Those revealing scents are also much longer lasting communication than howling, the topic of part one in this three-part series on how wolves communicate.
Harrington and Asa list a number of sources from which wolves produce scents:
- Urine: Wolves mark with urine frequently along the edges of their territory, creating what David Mech and Luigi Boitani call an "olfactory bowl." They mark more often when other wolves or coyotes intrude into their territory. Wolves raise their leg when urinating, possibly to give the urine more chance to be found. The height of the urine may also send a message about the stature of the animal leaving it. Only dominant male and female wolves mark with urine. Males mark more often than females.
- Feces: Wolves also mark territory with their feces. They may leave feces on conspicuous objects and along trails and roads, often at junctions.
- Saliva: A male can obtain information about a female's reproductive state by licking the saliva on a female's muzzle.
- Anal sacs: Because anal sacs are surrounded by muscles that a wolf can control, a wolf can secrete on command. "The common greeting position, in which two individuals stand head to tail, suggests an interest in anal sac odors," say Harrington and Asa. The dominant wolf holds its tail away from the body, revealing the anal sac area. The subordinate animal holds its tail close.
- Feet: Wolves have sweat glands in the webs of their paws that leave a scent when a wolf scratches the ground.
- Skin glands: Wolves leave "distinctive odor fingerprints" that other wolves recognize.
- Back and tail: Wolves have glands in these areas that may produce scents that reveal a wolf's emotional state.
- Vagina: The vagina and uterus secrete odors that play a part in reproductive communication.
Harrington and Asa add that a wolf's sense of smell can work in conjunction with its sense of hearing to improve communication. A male wolf, for example, may smell a female's urine and conclude that her body is ready to mate. But her growls may tell him to back off. He better listen.
Cick here to read part one on howling.
Link to Living with Wolves on scent communication Rick Lamplugh is a wolf advocate and author of the Amazon Bestseller "In the Temple of Wolves: A Winter's Immersion in Wild Yellowstone." Available as eBook or paperback. Or as a signed copy from the author.