Guinea baboon

Physical description

Baboon refers to the large-bodied primates with marked sexual dimorphism and having females and young that are dependent on males for protection. Guinean baboons have a red tone to their fur, and are sometimes referred to as the red baboon. They lack hair on their hindquarters, and their faces are black with yellow-brown sideburns. Females' rumps are pink in color and males have a mane of fur around their heads and shoulders. A characteristic feature of baboons is their long molars and broad incisors. The long canines are evidence of sexual dimorphism in baboon species. Their forelimbs and hindlimbs are nearly equal in length and their digits on their hands and feet are relatively short and stout, making it difficult for them to climb.

Baboons are one of the largest groups of monkeys and are sexually dimorphic in body size (meaning the males and females have differing body sizes). They can range in weight from 13 and 26 kg (28–57 lbs), making them among the smallest of the baboon species.

Habitat and distribution

Generally found in woodland savannas, Guinea baboons seasonally congregate near permanent water sources, breaking off in the wet season into smaller groups. Baboon species are all allopatric, but some of their ranges do overlap, and some interbreeding does occur. These baboons are found in a wide range across Africa in savannah habitats. Its range includes Guinea, Senegal, Gambia, southern Mauritania and western Mali. Most typically they are in the forests and savannah of sub-Saharan Africa. They can also be found in grasslands, rain forests, and other open areas.

Ecology

Guinea baboons are diurnal, living on the ground instead of in trees, and typically sleep in trees at the terminal ends of branches. Their group size is widely variable and ranges from 40 to 200. However, the most common troop size is 30–40 individuals. Often, a pronounced male hierarchy and fierce competition for females happens within the group. This competition leads to sexual dimorphism among the species. When it comes to feeding, they are independent foragers, and females are always paired with males when foraging so they can be protected. Females may choose to follow the same males from year to year.

Diet

Like other baboon species, Guinea baboons will eat any available foods, but their main sources are fruits, roots, tubers, grass, seeds and leaves. They also will eat insects, worms, spiders, small mammals, birds and invertebrates.

Behavior

Socially, Guinea baboons have more in common with Hamadryas baboons than other baboon species, living in one male units, consisting of one dominant male, several females and juveniles, and often a follower male. These groups are usually small, but join with larger groups to form a troop; these groups sleep or forage together. The Guinean troops are large multiple-male, multiple-female troops with 50–300 baboons. The harems consist of two to five females which mate with the dominant male. However, despite their similarities, Guinea baboon social behaviour has a few noticeable differences from that of Hamadryas baboons. While male Hamadryas forcibly acquire females for their harems, utilising neck-bites to condition them to stay near, female guinea baboons select males at their own leisure, males typically using coercion to recruit them. In Guinea baboons, Harem masters are noticeably less strict with their female consorts than Hamadryas baboon harem masters. Female Guinea baboons often fraternize with other females from other harems and even other males without being reprimanded by their male consort. Females approach males to initiate mating behaviour as they please and even mate with more than one male (although they mate with the harem master the most), a far cry from the more "faithful" female Hamadryas baboons. As seen in chimpanzees, Olive baboons and various macaque species, this promiscuity most likely is practiced to hide the paternity of their infants as a counterstrategy against male infanticide, which occurs in Hamadryas baboons but hasn't yet been observed in Guinea baboons (although male guinea baboons have been observed temporarily kidnapping then returning infants). Male-on-male competition for females is noticeably reduced or absent.

Unlike Hamadryas baboons and some other species, Guinea baboons are not very good climbers and favor trees, rather than high rocks or cliffs for sleeping. The more dominant males sleep on the heavier, thicker branches near the trunk of the tree and lower ranking members and juveniles sleep on the smaller and weaker branches further from the trunk. During daylight hours, they spend the majority of their time foraging on the ground, running along in quadrupedal patterns.

Communication

The Guinea baboons have a host of vocal, visual, and tactile communications. Their several vocal calls each convey several different messages, and consist of predator warnings, signaling friendly intentions, submissive calls, and anger or frustration vocalizations. Many of these calls can be used in combination with either each other or with some other form of visual or tactile communication. Visual communications serve many of the same purposes as the vocal calls, and are often accompanied by some sort of vocal call. Lower ranking animals appease more dominant ones with an "Ack ack" vocalization and "Wahoo" alarm calls are uttered if a threat presents itself. Tactile communication is usually tied to visual communication and can range from mouth-to-mouth touching to biting or slapping. Male Guinea baboons are unlike other baboons species, as they form intimate friendships with other males, fondling each others genitals as a gesture of greeting, as well as mounting each other and huddling together.

Reproduction

Female Guinea baboons exhibit sexual swelling that begins about 10 to 12 days before it peaks and remains consistent for about eight days afterwards. Females then participate in the social behavior of presenting, which is when she signals to the males in the group she is ready for copulation.

The mean gestation period is about six months and nursing continues until about six to eight months. Females rebuff a male's advances by shrieking at him and often climbing up a tree.