OLFACTORY COMMUNICATION

 The Importance of Olfaction in Communication

Olfaction, the sense of smell, is the most acute of the wolf's and dog's senses. Wolves and dogs, unlike humans, are strongly reliant on odors to aquire information about the outside world...about food or danger, and to communicate with other wolves.
 Unlike vocal signals, that indicate state of an individual's changing mood and possible future actions over the next few seconds or minutes, the odor provide a deeper and broader window into the animal's history, present status, and future prospects over much longer time frame.
For example, while a female's urine may inform a male that she is psychiologically ready to mate and concieve, her voice may inform him that now is not the time.

Odors contain information on species or individual identity, gender, breeding condition, social status, emotional state, age, condition and even a diet.



Skin Glands

The secretions of the wolf's or dog's skin glands not only keep the skin supple and hydrated, but also function in chemical communication. There are three types of secretory skin glands.

a) Sebaceous Glands
Found in hair follicles. They produce an oily, waxy substance, which when acted on by bacteria, emits distinct odor. In dogs, large sebaceous glands are found along the part of the neck, back and tail, especially in the tail gland area. However, those present at the junction of the skin and mucous membranes of the lips, vulva, and eyelids are even larger. If you live with more than one dog, you may often notice, that your dog's sniff, or sometimes even licking, each others at the above mentioned areas. Commonly, you will see this behaviour from the most dominant dog within your family pack.

b) Apocrine Sweat Glands
Found in the skin of dogs. They are most numerous on the face, lips, and back and between the toes. Apocrine glands become active at puberty. Their watery secretion is not used for cooling.

c) Eccrine Glands
They are the true sweat glands that function primarily for cooling. In dogs they are located only on the footpads. Their secretion is influenced by excercise or heat stress, but can be also stimulated by the nervous system. Individual differences in microflora and in diet result in the functional equivalent of "chemical fingerprints". Thus, wolves can recognize one another by distinctive " odor fingerprints", dogs can not only identify individual humans by odor, but can distinguish between identical twins that are eating different diets.


Feet
Appocrine sweat glands are present in the "webs" of the paws, in the form of small glandural pockets near the bases of the toes of dogs. Eccrine sweat glands, are numerous in the footpads. The offten seen stiff- legged scratching of the ground after a defecation, and in some individuals after or before urine marking, lay down an aditional scent mark from the paws. This behaviour is presented by dominant male dogs, or by the alpha breeding pair of wolves. So next time you see your dog doing so, it means he's laying down additional scent mark, and not cleaning his feet, as many people believe.

Marking with back feet

Paws sweat glands

Back and Tail
Little attention has been paid to the skin on the backs of canids in terms of signal value. Wolves, for example, have contrasting colour marking across the shoulders, and the relatively longer guard hairs covering that area are raised during periods of arousal. Also called "hackles", these raised hairs convey an obvious visual signal that can be seen also in domestic dogs, and can be recognized even by humans. The passive release of scent from the raised hair, during which the skin folds spread, might also play important role in communication.
Clusters of sebaceous glands, together with apocrine galnds, make up a dorsal tail gland found on the top surface of the tail near to its base. Wolves nor dogs don't typically investigate this area on one another, some might rubb the secretion on their dens, kennels or crates.

Raised hackles

Ears 
Male dogs show little interest in the ear wax samples of other males, but investigate the ears of females. These results suggest, that the information in the ear wax samples is related to gender. Many times, you will also find dogs showing interest in smelling human ears.

To be continued.....

DEVELOPMENT OF VOCAL COMMUNICATION

  From birth on, both wolves and dogs are very vocal. Newborn pups moan, squel, and scream as they wiggle around and compete for the mother's nipples.

Early Vocal Signals
( Squeal / Scream / Yelp / Yawn ) 

Pups squeal and scream during their first few weeks of life, but rarely by 5-6 weeks of age. These sounds are short, harmonic, and high-pitched. Screams are generally higher-pitched, much louder and less frequent. Squeals are not associated with any particular pup or adult behaviour, and adults appear to ignore them. When pups scream, their mother grooms them or repositions them, often eliciting more screams. Scream serve as a mild distress calls.
Pups yelp when stepped on or being carried, and their mother responds promtly by attending to them.Yelps are rare, brief, loud sounds.
Yawns are sounds produced during yawning and have no apparent social role.

Early Adultlike Vocal Sounds
 ( Moan / Whine / Growl / Bark )

Moans are most common pup sound.Moans, like squeals, screams, and whines are most common during first two weeks of life when pups are deaf. Pups moan while nursing, asleep, or resting; their moans do not elicit any overt response response from the mother. Pups also moan when huddled together, providing a possible tactile signal to the littermates. 
Pups also whine from birth on. Whines are higher-pitched than moans. Pups whine and moan in the same contexts, so the two vocalizations may carry similar information.
Pups growl as early as a day, but not frequently until their fourth week. During the first 3 weeks, pups may growl when huddled. Older pups growl during active interactions with litermates. Pups also bark in response to sounds outside.



Late Adultlike Vocal Signals
( Woof / Squeak ) 

Pups woof from their third week on, most often during their mother's absence. Woofs are associated with both hesitancy, and aproach and reflect uncertainty. 
Pups do not squeak until day 15, by by the week 4, squeaks become the most common sound in the pups repertoire.  
In weeks 3 and 4, pups squeak while in contact with one another but not interacting. During the next 2 weeks, they squeak mostly during interactions with littermates or with their mother. 

The Neonatal Vocal Repertoire 

The vocal repertoire of newborn pups begins to give way to an adult - structured repertoire shortly after the pups can see, hear and move about. Four most common sounds of newborns ( moans, whines, squeals, screams ) are made repeatedly during first 2 weeks of life, then decline rapidly or disappear entirely. Together with the yelp, these four sounds provide a stepped series that permits the mother to monitor the status of her litter. The decline of these early sounds indicate that pups rapidly outgrow the need for distress signal system. By 3-4 weeks of age, pups can avoid situations that may have been life - threatening earlier. Loss of squeals and screams still leaves moans, yelps and whines to indicate low, moderate or high level of distress. 
At 1-3 weeks, before the development of social behaviour, pup signals primaly serve to indicate distress. After 3 weeks of age, these vocal signals assume their adultlike roles. These are mainly used by wolves in a form of howls.