Baboon Communication

Sunrise

 

I like to refer to my chacma baboons as “explicitly social.” Their intra-group interactions are quite obvious, and at times utterly blatant. It is not unusual to hear baboons screaming, grunting, wahooing, or kecking at each other regularly and it is those loud vocalizations that allow us to track and locate the troops in the early mornings before dawn. Baboons act how they feel and their behaviors are extremely unrestrained.

Baboons communicate through a variety of complex interactions that include visual, auditory, and tactile signals. Communication acts as a vital catalyst for sociality and can arguably be seen as the most essential component of social systems. Baboons interact in a diversity of ways to convey to others their mood. Below are some of the most common forms of communication that I have witnessed with the chacma baboons of the Cape Peninsula.

Visual Communication

Proximity signals- To a baboon, your spatial positioning within the group is crucial. Certain baboons are allowed to sit, forage, or rest nearby each other, while other baboons are excluded. The proximity, or distance, between individuals can be an indicator of social status and relationships. Some baboons will follow others around, while others will actively avoid each other.

The female Zebra presents to the dominant male (photo credit SG Davis)

Presenting- This behavior is done by both male and female baboons and occurs across all age ranges. One baboon approaches another and displays its backside for inspection. Social presenting, in particular, is seen as a submissive gesture where a subordinate individual presents to a dominant one. When a male presents to another more-dominant male, the dominant male will hip-touch or place his hands on the hips of the presenter, as an act of recognition. Sexual presenting occurs when a female (usually one in estrus) presents to a male in order to solicit copulation. Males will genital-inspect females often before mating. Many times presenting behaviors are accompanied by lipsmacking (see below).

Eye-threats- When a baboon wishes to display animosity or agonism towards another, they raise their eyebrows to reveal their pale eyelids and stare directly at another baboon. This is usually a sign of aggression.

Yawn-threat and open-leg posture by the male Julius

Yawn-threats- Typically administered by adult/sub-adult males, this gesture involves a deep yawn that exposes the canine teeth. It is a sure sign of discomfort and a precursor to aggression. If you are ever near a baboon that yawns, it is probably time to move away.

Grimace- A grimace is an expression with barred teeth and the corners of the mouth pulled back so the mouth is partially open (almost like a smile). Baboons will grimace in submission towards dominant individuals.

Gazing or staring- Baboons will stare at another baboon for two broad reasons: they either love that baboon or they dislike that baboon. Males will gaze at a lovely little female if they want to consort with her. Alternatively, staring can be seen as a threat behavior, where one baboon is attempting to warn or intimidate another.

Display- Male baboons will sporadically make a form of visual display in order to threaten or intimidate other males or females. This can involve ground-slapping or shaking of branches in order to make the male appear formidable.

Open-leg displays- This type of visual display is really a way for males to inadvertently signal to other males their presence and show off their decorations by sitting with their legs spread apart. Enough said.

Auditory Communication

Wahoo calls- adult males make a resounding two-part medium frequency call that resembles a dog barking, but has two distinct sound components: a “waa” and a “hoo.” Males shout this “wahoo” call out during aggressive interactions with other males or other troops, when herding females, or if they are lost and trying to find the rest of the troop.

Harrison lipsmacking with his little pink tongue out (photo cred: SG Davis)

Lipsmacking- Lipsmacking involves rapid movement of the tongue and lips apart and together. It is one of my favorite behaviors that baboons do towards each other, because not only is it a friendly and affectionate action, but it is very endearing.

Grunting- Baboons grunt all the time. To say that they are happy and content. To relieve tension. To say hello to another baboon. To interact with the troop. And sometimes, they grunt just because they want to. A grunt is a low-frequency vocalization emitted with the mouth closed or slightly open, usually punctuated by brief silences.

Copulation call- Female baboons make a very loud call right at the end of copulation. They pucker up their lips and puff out their checks to emit a noise that builds in amplitude and climaxes with loud breaths of air. Some scientists believe this call may be a fixed response, for females also make a call similar to this when defecating (you can fill in the details as to why).

Kecking- A keck is a staccato-like submissive call of medium-frequency. In order to keck, a baboon pulls its lips back in a grimace and makes short loud sounds punctuated by silences between each syllable. Kecking usually occurs when a baboon is feeling subordinate or wants to show respect to a dominant individual (unless you are the female RoseMarie, who kecks at everything that moves for no apparent reason).

Pitt jibber-jabbers to the infant Bonaparte

Jibber jabber- Adult males and females will jibber-jabber at small infants as if to say hello to the babies. A jibber-jabber is a vocalization that sounds like a series of excited and rapid grunts with audible inhaling and exhaling sounds. My favorite is when the adult males like Harrison jibber-jabber at the miniature black infants.

Scream- This sound is reminiscent of a human baby scream or the squawk of a bird. It is loud and high frequency. Usually females, juveniles, or infants will scream when they feel threatened or hurt by another individual. Not unlike humans.

Bark- Baboons will bark as a warning call. It is a short vocalization similar to a dog’s bark and given when a female feels at risk of separation from her infant or when the troop may be at risk of a predator or danger (alarm bark).

Chattering- The juvenile baboons love to jabber and chatter with one another, making indiscernible noises back and forth and little nasal grunts when playing and wrestling.

Tactile Communication

Grooming (photo credit: SG Davis)

Grooming- Grooming is of utmost importance to many primates, and chacma baboons are no exception. Baboons sift through the hair of other individuals frequently, picking out bugs or dirt lodged against the skin. Grooming is an affiliative behavior and highlights the type of relationships between individuals, including friendships, family, and social-rank. Grooming is also a great way to reduce parasite loads and clean fur/skin.

Mounting- In addition to mating, baboon individuals will briefly mount each other as a sign of reassurance and affiliation.

Nose-to-nose- Friendly baboons or male and female consortship pairs will occasionally touch noses in affection. It’s a sweet little gesture to witness.

Aggressive contact behaviors- Baboons will engage in aggressive behaviors that can at times culminate in adverse physical touch. Males will herd their females, chasing them, biting them, standing on them, hitting them, and grabbing them (not the most pleasant thing to witness). Very infrequently, I have observed two males engaging in physical fights. Fortunately in terms of amity, the baboons I study are generally significantly good-natured towards each other in comparison with other species.