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

References:

1.  Bradshaw JWS. The Behavior of the Domestic Cat, CAB International, Wallingford, England, 1992.

2.  McKinley PE. Cluster analysis of the domestic cat's vocal repertoire. PhD Dissertation, University of Maryland, College Park, 1982.

3.  Moelk M. Vocalizing in the house cat: a phoenetic and functional study. Am J Psychol 1944;57:184-205.

4.  Remmers JE, Gautier H. Neural and mechanical mechanisms of feline purring. Respir Physiol 1972;16:351-361.