GUINEA BABOON

Papio papio

Geographic Distribution and Habitat

The Guinea baboon (Papio papio), also known as the red baboon, is widespread across West Africa and the southwestern Arabian Peninsula. Populations are found in Guinea, Guinea-Bissau, southern Mauritania, western Mali, Gambia, Senegal, and northwestern parts of Sierra Leone.

Compared to other baboons who prefer savannas and arid climates, Guinea baboons occupy areas with high variation in precipitation and seasonality. Their biomes are diverse and regularly overlap, including semi-deserts, savannahs, Sahelian steppe (a flat, grassy plain), woodlands, wet forests, and even mangroves! A rule of thumb for this species is they are always found near a permanent water source, from freshwater springs and marshes to rock pools and mountain rivers.

TAXONOMIC NOTES

Guinea baboons have five closely related species in their genus: chacma baboons (P. ursinus), yellow baboons (P. cynocephalus), Kinda baboons (P. kindae), olive baboons (P. anubis), and hamadryas baboons (P. hamadryas).

In eastern Mali, Guinea baboons have hybridized with olive baboons in overlapping areas. Although documented, substantial research has not been gathered on these individuals.

It is important to note that while current data recognizes six distinct species, controversy exists among taxonomists. Some argue there is only one species of baboon with several subspecies based on recent molecular studies. Research is still being conducted on this matter.

Guinea baboon range, IUCN 2020

Size, Weight, and Lifespan

Guinea baboons live for several decades—anywhere from 35 to 45 years—and weigh between 28.6 to 57.2 pounds (13–26 kg). They are the smallest baboon species. Despite their “petite” stature within their genus, they can travel up to 28 miles (45 km) per hour!

These baboons are sexually dimorphic in size. Males have a slight size advantage over females and reach 19.7 to 32.7 inches (50–83 cm) in length. Females are smaller, only 17.7 to 27.6 inches (45–70 cm).

Appearance

Sometimes referred to as the red baboon, Guinea baboons have a reddish-brown coat that covers the cheeks, back, arms, and abdomen. Males have denser fur and a thick cape of hair that drapes around their neck and shoulders. Western-range baboons are lighter in color, while eastern individuals sport a darker pelage.

Guinea baboons have arched tails and bare, calloused rumps. Front and hind limbs are the same length with stubby fingers and toes, leaving them as notably poor climbers.

Crimped, wavy hair surrounds their hairless faces, which are a striking shade of dark purple. Certain areas near their eyes and around their nostrils may fade to a faint rosy, tan color. Their faces slope downward into long, protruding “dog-like” snouts. Compared to other baboons, they have very broad incisors and long molars. Males have longer canine teeth than females and can reach up to 2 inches (5 cm).

Diet

Guinea baboons are opportunistic and adaptable omnivores. Like humans, they have great diversity in their diet. Unique ecological ranges and seasonality greatly influence their food selection. A wide assortment of woody plants (trees, shrubs, and lianas), fleshy and dry fruits, seeds, young leaves, flowers, buds, insects, invertebrates, eggs, and birds make up their diet.

A key food source is the Borassus akeassii fruit, which grows abundantly in forests along rivers and wetlands. Guinea baboons eat this fruit at all stages of its growth, which is why it is considered a year-round staple. They also forage herbaceous plants such as Echinochloa spp., Chrysopogon spp., and Costus spectabilis, and aquatic species (Nymphaea lotus), as well as other floating water plants, shoots, roots, and fungi.

If agricultural land is accessible, Guinea baboons will take yams, groundnuts, maize, and rice. This causes conflict with farmers.

Meat is occasionally consumed. They are known to hunt hares and small fiddler crabs. On very rare occasions, Guinea baboons will consume the leftover rumen (stomach) and the intestines from recently deceased cattle from nearby farms, as well as harnessed bushbucks and red-flanked duikers.

For a salty snack, Guinea baboons venture into caves and lick the walls—presumably, for extra sodium.

Behavior and Lifestyle

Guinea baboons are diurnal, meaning they are awake during the day and sleep at night. They are primarily terrestrial (ground-dwelling) and travel quadrupedally as they forage in small groups, scaling various landscapes for food. Male-led groups fuse and drift apart depending on daily activities and safety. Groups are always situated near a permanent body of water.

The sleep site selection patterns of Guinea baboons are quite exceptional. To avoid predation, anywhere from 40 to 100 individuals band together before retiring for the night (there’s always strength in numbers). Groups seek trees (preferably palms) with wide trunks that are difficult to climb. To reach a branch, they leap from a taller access point—a nearby tree, rocky ledges, and even cliffs. They strategically avoid forks and knots, and nest in the furthest terminal branches. Males sleep closest to the trunk to protect females and young. At daybreak, males descend first before the groups break apart for foraging. To keep in touch, males emit bark calls when visibility is low.

Fun Facts

A group of baboons is referred to as a gang, troop, flange, or congress.

Guinea baboons filter their drinking water. If they do not have access to fresh flowing water, they will dig wells in the sand close to unfit bodies of water. The sand helps filter pathogenic germs to make it potable (drinkable). Tests have proven that this method effectively removes the germs from the wells.

Never complain about bedtime again! Guinea baboons sleep in palm trees with trunks that are too wide to climb to avoid predation. To access the branches, they leap off nearby trees or cliffs. Practiced adults teach their young and sometimes individuals fall. Fearful juveniles have been seen screaming before the leaping point and even “chickening out.” Can you blame them?

Daily Life and Group Dynamics

Guinea baboon’s social dynamics are somewhat unique compared to other Papio species. They live in intricate, male-dominated, multi-faceted social groups. Their relationships are complex, but also very accepting and often promote positive social engagement. Their multi-level, fission-fusion social structure—in which groups join together or break apart based on the groups’ needs and activities—includes stable bonds between males and females as well as a high degree of male‐male cooperation and tolerance. Within this social structure, male Guinea baboons showed far less rivalry between and among other males, regardless of relatedness, as well as less aggression towards females than some other baboon species.

The first level of organization begins with a social group called a one-male unit (OMU). It consists of one male, a small band of females (usually one to four, known as a harem), and their young. Males do not aggressively herd their units but instead motivate and persuade movements by corralling, shaking, and jumping. If a traveling group needs to change direction, a male will speed up and begin to prance about to encourage a turn.

The next level of organization occurs when multiple OMUs band together to form what is known as a party or clan. Several parties come together and become a gang. Some gangs can have 300 to 500 individuals. This is an expression of fusion, which comes in handy when sleeping, traveling, defending against predators, or participating in productive social activities. Clans often break apart (fission) when they awaken and begin foraging for the day.

Grooming is a critical method for bonding and emotional connectivity and frequency relates to social preference.

It is important to note that, unlike other species, female Guinea baboons have a high degree of freedom. Males do not restrict their movements and consent to an open choice of social partners. Females are free to visit with relatives who have left for different OMUs. They’re even allowed to be shared with males from other groups—a practice that would typically trigger competition and conflict in other baboon species. The behavior of Guinea baboons prompts researchers to expand their ideas of social group patterns and systems.

Communication

Guinea baboons are highly social monkeys that use physical and vocal communication methods.

Physical communication varies and depends on context, social setting, and individuals’ moods. Touching, posture, and facial expressions—such as certain blinking patterns or staring, the twitch of the ear or lip, and even a yawn—may not seem like much to us, but to them, present colorful language. In affiliative or social situations, males are known to fondle another when greeting a bonded member or friend.

Grunts are the most common and are exchanged during greetings, affiliation, copulation, and infant care. Guinea baboons may scream during agnostic interactions.

During foraging, if males cannot see more than 5–10 members of their subgroup, they will use a “wahoo” call for intergroup spacing. This is also used when they spot a predator or a different gang. A series of roar grunts is often exchanged during travel, or if females are acting aggressively. In these cases, they are known to flee up trees, yawn, and shake branches in protest.

Females use bark calls during travel, during foraging, or if they are harassed by another female. This may also elicit yawns, screams, or branch shaking.

Reproduction and Family

Mating takes place year-round and encompasses polygynous and polygynandrous behavior. Both males and females will approach one another to engage in copulation. Females reach sexual maturity at the age of four and can breed every one to two years. When a female is ready to mate, her bottom will turn red and swell up, indicating to males she is ready to breed. Once a female is pregnant, gestation lasts for 184 days and she will birth a single infant. A mother will nurse and care for her baby until they are six to eight months old.

Once grown, females are free to remain in their clan or join another. Female relatives often recognize each other in large groups and mingle. Males leave their birth group upon sexual maturity. If they do not find a new group right away, they sometimes band together with other bachelors and form an all-male unit (AMU).

Ecological Role

As traveling foragers, Guinea baboons help disperse seeds across a wide variety of ecological zones. They are a prey source for the African crowned hawk-eagle.

Conservation Status and Threats

The International Union for Conservation of Nature lists the Guinea baboon as Near Threatened (IUCN, 2018). Habitat loss, agricultural land use, logging and timber harvesting, and hunting pressure are critical threats to the species.

Humans hunt this species for a variety of reasons. Farmers poach or poison Guinea baboons for invading their fields, foraging their crops, and to eliminate resource competition for water. (Baboons are often blamed for contaminating water meant for livestock with their feces.)

Other hunting motivations include politically backed hunting excursions and trade (pelts and body parts are used for medicinal magic practices). It has been reported that large groups of individuals have also been captured in Senegal for laboratory use and experimentation.

Conservation Efforts

The Guinea baboon is listed in Appendix II, Class B under the African Convention, and under Appendix II of CITES, an international agreement between governments whose goal is to ensure that international trade in specimens of wild animals and plants does not threaten their survival. They are also fully protected by Guinea-Bissau law.

There are several protected lands where Guinea baboons are found. Niokola-Koba National Park in Senegal is credited with fostering a large population that offers researchers ample information.

The following areas are also listed as protected sites across the African region: Boucle du Baoulé National Park, Outamba-Kilimi National Park, Kiang West National Park LRR, Gambia River National Park CRR, the Bao-bolon Wetland Reserve North Bank Region, Kunkilling Community FP CRR, the Pirang Bonto Forest Park and at Kiti forest, River Gambia National Park (Baboon Island); Bafing-Falémé transboundary protected area; Bafing Chimpanzee Sanctuary, Wongo National Park, and Kouroufing National Park.

References:
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  • Maciej, P., Ndao, I., Hammerschmidt, K. et al. Vocal communication in a complex multi-level society: constrained acoustic structure and flexible call usage in Guinea baboons. Front Zool 10, 58 (2013). https://doi.org/10.1186/1742-9994-10-58
  • Patzelt, A., Zinner, D., Fickenscher, G. et al. Group Composition of Guinea Baboons (Papio papio) at a Water Place Suggests a Fluid Social Organization. Int J Primatol 32, 652–668 (2011). https://doi-org.ezproxy2.library.colostate.edu/10.1007/s10764-011-9493-z
  • Zinner, D., Groeneveld, L.F., Keller, C. et al. Mitochondrial phylogeography of baboons (Papiospp.) – Indication for introgressive hybridization?. BMC Evol Biol 9, 83 (2009). https://doi.org/10.1186/1471-2148-9-83
  • Zinner D, Klapproth M, Schell A, Ohrndorf L, Chala D, Ganzhorn JU, Fischer J. Comparative ecology of Guinea baboons (Papio papio). Primate Biol. 2021 May 21;8(1):19-35. doi: 10.5194/pb-8-19-2021. PMID: 34109265; PMCID: PMC8182668.
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Written by Dana Esp, October 2023