Vocal communication
two-phase bark: A deep, loud call, emitted by adult males, which is repeated at 2 to 5 second intervals and sounds like "wahoo". This call is emitted when a predator is near especially a feline one. It is also heard when there is inter or intra group aggression between males. It also communicates male presence and arousal.
grunting: This sometimes resembles a two-phase "uh-huh" and generally is soft in nature. This call is a threat call, emitted by the adult male, which can occur before two-phase bark.
screeching: This call consists of high pitched screams which are repeated and may turn to a churring noise when the individual becomes caught. This call is emitted by all age classes and both sexes.
yakking: Short in duration and sounds like a sharp "yak". Fear grimace often accompanies this call. This call is emitted by subadult and adult males and females, and is given by an individual who is withdrawing from a threatening animal.
clicking: This call is chirplike in nature and is emitted by infant and juvenile chacma baboons of both sexes. This is the equivalent of yakking (Estes, 1991).
ick-ooer: A two-phased call with the "ick" coming before the "coo" sound, and given with the lips pursed. it is emitted by infants of both sexes, and is given as an expression of a low-level of fear or distress.
shrill bark: This call is a sound which is single, sharp, and explosive in nature. it is emitted by all chacma baboons except adult males, and functions as an alarm signal especially to a sudden disturbance. Other members of the troop will flee upon hearing this call.
rhythmic grunts: This call is low and soft and is given by all chacma baboons except infants. This call is given when one individual is approaching another and signals friendly intentions.
doglike bark: A high-pitched call and has more quaver and is less staccato than the shrill bark. it's emitted by subadult and adult males and females, and is given when individual or subgroups are separated from the troop.
chattering: This call is nasal in nature and consists of rapid gruntlike sounds. It is emitted by juvenile chacma baboons, and is heard during play.
muffled growl: The mouth is closed and the cheeks puff in and out during this call. This call is emitted by estrus females and occurs during copulation.
Visual communication
tension yawning: This is done by an adult male chacma baboons. The mouth is opened fully to reveal the canines. This is done when a rival group or a predator is approaching.
staring: This display is used as a threat. The eyes are fixed on the stimulus, the eyebrows are raised and the scalp is retracted, the facial skin is also stretched by moving the ears back.
canine display: This is performed by adult male chacma baboons, and is variation upon tension yawning. It serves as a threat display and is given by a lower-ranking male against a higher-ranking one when the higher-ranking individual is with an estrus female or is eating meat. Often eyebrow-raising occurs with this display.
eyebrow-raising: Eyebrow-raising functions as an aggressive gesture.
penile display: This is performed by an adult male, and he will sit with this erect penis in full view. This display is performed while the male is guarding and communicates to other males that an adult male is present in the troop.
fear grimace: The lips are retracted so that the teeth are shown; the teeth are clenched together. This display functions as an appeasement signal to reduce aggression in aggressive encounters.
tooth-grinding: The mouth is closed and the teeth are grinded together. Heard when two males are threatening each other at a close distance.
rapid-glancing: This is when a threatened chacma baboon will turn its head away and look in the opposite direction. It serves to decrease the tension in the situation.
lipsmacking: The lips are protruded, then smacked together repeatedly. It's a reassuring display.
social presenting: This is like presenting, but is done by females and juvenile males towards higher ranking males. This is a submissive display and differs from presenting by the hindquarters being lower. This is also done by a female to another female with a black infant, and she will lip-smack while doing this.
Tactile communication
social grooming: One individual removes parasites and dead skin with their hands from another individual. In this species it generally only occurs between same sex individuals. This is used to reinforce the social bonds.
nose-to-nose greeting: When two individuals meet each other they touch noses as a friendly sign.
social mounting: This is generally a response to social presenting and serves to signal a friendly reassurance. This is also seen during aggressive encounters.
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