ACVC 2001 - How Animals Perceive the World: Non-Verbal Signaling

How Animals Perceive the World: Non-Verbal Signaling

Karen L. Overall, MA, VMD, PhD, DACVB, ABS Certified Applied Animal Behaviorist

Introduction:

The uniting feature that connects all social vertebrates is the extent to which they signal non-verbally. Communication involving ritualized displays or graded signals is used to confirm or reject information received from others in social interactions, to indicate species, sex, and sexual receptivity, to signal about issues pertaining to status, and to otherwise negotiate all social interactions. As such, communication can involve such instantaneous behaviors as tactile and visual displays. These are relatively "short-distance" signals. Vocal communication is also instantaneous, but may reach over longer distances. Verbal communication is only one variety of vocal communication, and both of these may pale when the full story of olfactory communication is written. Certainly, olfactory and pheromonal signals provide information that can be assessed over distances and across time.

When assessing any communicatory structure it is important to realize that signaling involves a set of rules that will be shaped by the evolutionary history of the species. The story of canine domestication is the story of work and work-related tasks. The story of feline domestication is the story of rodent and vector borne diseases and their prevention. These 2 divergent paths to domestic life-styles have been shaped by, and in turn have continued to shape factors like reproductive schedules, fecundity, age at first reproduction, age at sexual and social maturity, composition of family or group units, and social interactions within these units. To understand such behaviors it is critical to understand the component signals as they are used to communicate with conspecifics. The following tables provide an introduction to this topic.

CANINE SIGNALS

Signal	Circumstance Information
barking	alerting/warning attention-seeking
growling	warning distance-increasing
crying whimpering whining	et-epimeletic
howling	elicit social contact anxiety situations (social contact = reassure)
moans	pleasure, contentment
tail and ears up; forefoot in front of other	alert, ready to participate
direct gaze	challenge confidence absence of threat distance-increasing
averted gaze	fear cowardice deference absence of challenge (not the same as deference for confident, high-ranking dogs) distance-decreasing signal
belly presented	deference - if neck, back, and other solicitation bues given disengagement - if inguinal area and, or chest covered may become aggressive if pursued relaxation - if flaccid
tail tucked when belly presented	fear/submission
tail tucked when belly presented with urination	profound fear/submission
grin	deference distance-decreasing signal
piloerection	arousal associated with anxiety, fear, agression distance-increasing
piloerection restricted to neck or tail region	confident dog
rigid stance, stiff torso musculature	confidence and intent to interact (may not be aggressive) distance-increasing
tail above horizon	confident high status
tail below horizon	less confident lower status deference fear
tail wag	willingness to interact
tail tip wag; stiff	confident assertive offensively interactive
neck erect or arched	confident challenging
ears erect	alert confident
ears back	fear
ears vertically dropped	deference submission low rank anxiety
snarl/growl with only incisors and canines apparent	confident offensively aggressive distance-increasing
snarl/growl with all teeth and back of throat apparent	defensively aggressive fearful distance-increasing
body lowered	defensive distance-decreasing fearful deferential relaxed
licking lips, flicking tongue	appeasement et-epimeletic distance-decreasing anxious (and solicitation of reassurance; derived from et-epimeletic)
raising forepaw	distance-decreasing solicitation of attention deference (off balance)
paws out, front end down, rump up, tail wagging	body bow, invitation to play
perpendicular posture	challenge confidence
mounting or pressing on back shoulders of another dog	challenge marking, claiming
licking at corner of another dog's (or person's) mouth	et-epimeletic deference solicitation
blowing out lips/cheeks	anticipation (positive or negative) anxiety (if very fast)
popping or snapping of upper and lower jaws (bill pops)	capitulation, intention to comply as a last resort

Feline tail postures (Adapted from Bradshaw, 1992).

vertical	play greeting, often with motion sexual approaches by females frustration (of whipped)
half-raised	sexual approaches by females
horizontal	amicable approach sexual approach by females
concave	defensive behavior
lower	offensive aggression (if rigid and flicking)
between the legs	submission fear

Interpretation of feline vocalizations from Moelk (1944) and McKinley (1982).

Call	Description/Interpretation
Murmur	Rhythmically pulsed vocalization; exhalation; social interactions, solicitation, non-threatening; possibly die to dysynchronous contraction of muscles in larynx and diaphragm (Remmers and Gautier, 1972(
Growl	Low pitched, harsh; agonistic; lengthy
Squeak	High pitched; raspy; anticipation of feeding, females post-copulation
Shriek	Loud, high pitched; pain, fear, aggression
Hiss	Agonistic, mouth open, teeth visible; offensively defensive (avoids frank aggression)
Spit	Short sound before or after hiss
Chatter	Anticipatory, frustration
Purr	Contentment, nursing, mild conflicting anxiety
Chirr	Queen's call to kittens
Mew	High pitched, medium amplitude; mother-kitten interaction for location, ID, encouragement
Moan	Low frequency/long duration; epimeletic; regurgitation, solicitation
Meow	Greeting, epimeletic, willingness to interact