Geladas (Theropithecus gelada) are big and robust primates from the Old World monkeys, with dark brown fur. Males have long and thick manes and a bright red hairless hourglass-shaped skin patch on their chest, surrounded by white fur. Females also have these bare patches on their chest, but they only brighten when in oestrus. Together with the reddening of the patches when these ladies are ready to mate, they also flaunt a necklace of pearls around their chest patch. These 'pearls' are actually fluid-filled blisters, and are thought to have evolved because unlike the closely related baboon, geladas spend most of their time sitting on their bums, eating and chatting.
The gelada feeds on the ground by shuffling around in the squatting position, moving bipedally, little by little, without changing their posture. Feeding is made even easier because of their sturdy and small fingers, which are adapted for pulling grass and digging. They also have small incisors to make the chewing of leaves easier.
Geladas are only found in Ethiopia, in the deep gorges of the Ethiopian plateau. They are restricted to high grassland escarpments and mostly inhabit altitudes between 2000 and 3000 meters. They prefer to sleep on ledges on the cliff faces, and around sunrise almost immediately move to the top of the plateau and start their socialising and feeding activities.
Many predators threaten the gelada, including leopards, jackals, dogs, foxes and hyenas. To escape these bandits they flee to the cliff faces, but sometimes brave males will show off by confronting the threats, and in some cases even mob the predator. Unfortunately, as in most cases, humans also pose a threat to these chatty primates and their habitat, because of deforestation and soil erosion, due to the ever increasing population of the human race. Some are also shot as pests, while others have also been held as laboratory animals in the past.
Despite the increasing threats to the species, they are listed as Least Concern on the IUCN Red List, as they are still abundant and have a large range.
Speech evolution from geladas??
A recent study suggests that the lip-smacking sounds made by geladas may be a clue as to how human speech evolved. Read the interesting article and listen to their eerily human chattering.
Gelada baboons are found only in the highlands of Ethiopia and Eritrea. A majority of gelada baboon populations live in Gich and Sankaber areas of the Semien Mountains National Park in Ethiopia.
Biogeographic Regions: ethiopian (Native )
Male gelada baboons weigh an average of 20.25 kg. Their bodies are 69 to 74 cm in lenth while their tails are an extra 45 to 50 cm long. Female geladas are somewhat smaller. They weigh an average of 14.8 kg, are 50 to 65 cm in body length and their tails are 30 to 41 cm long. (van Hooff, 1990: 258)
Members of both sexes have short rostrums and wide nostrils. They have short brown fur and both males and females have a hairless patch on their chests, usually triangular in shape, which is outlined by white hairs. The color and size of this patch in both sexes is dependent on hormonal changes in the females. Both sexes have pale eyelids which are used for expression. Males are marked by the presence of whiskers and a brown hairy mantle. (Stammbach, 1987; van Hooff, 1990)
Range mass: 13 to 21 kg.
Range length: 50 to 74 cm.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
Sexual Dimorphism: male larger
- van Hooff, J. 1990. Macaques and Allies. Pp. 208-286 in S Parker, ed. Grzimek's Encycolpedia of Mammals. New York: McGraw-Hill Publishing Company.
Gelada baboons are found inhabiting the high grasslands of Ethiopia and Eritrea, especially in the Semien Mountains National Park. Geladas prefer to sleep on rocky cliffs, from which they descend in the morning to go foraging in the nearby grasslands. Most of the gelada populations are found foraging in grasslands between 2,000 and 5,000 meters (Stammbach, 1987). This is a terrestrial species and is very specialized to this particular habitat.
Range elevation: 2,000 to 5,000 m.
Habitat Regions: tropical ; terrestrial
Terrestrial Biomes: savanna or grassland
- Stammbach, E. 1987. Desert, Forest, and Montane Baboons: Multilevel-Societies. Pp. 112-120 in B Smuts, D Cheney, R Seyfarth, R Wrangham, T Struhsaker, eds. Primate Societies. Chicago: The University of Chicago Press.
Gelada baboons are exclusively herbivorous, but their choice of food changes depending on seasonal availability. During the wet season (July and August), when green grass blades are abundant, they make up 93% of the diet of these baboons. In November, when the grasses have seeded, the seeds make up 70% of their diet. During the dry season (January and February), 67% of their food is grass rhizomes and 25% grass blades (Dunbar, 1977). Geladas are also known to harvest fruits, tubers, and flowers and stems throughout the year. (Dunbar, 1977; Kawai, 1979)
Gelada baboons are highly specialized feeders. The opposability of their first two digits is the highest of all the catarrhine primates and allows them to pick grass blades individually so that they can sort good grass from bad grass during the dry season. It is also notable that their phalanges are short and robust, which allows them to dig efficiently for tubers when desired. These specializations allow gelada baboons to take advantage of grassland environments that other primates could not inhabit as successfully (Dunbar, 1977).
Plant Foods: leaves; roots and tubers; wood, bark, or stems; seeds, grains, and nuts; fruit; flowers
Primary Diet: herbivore (Folivore )
As grass feeders, gelada baboons are likely to have significant effects on the plant communities in areas where they feed. By digging for roots, tubers, and grass rhizomes, these animals help to aerate the soil. As possible prey items, these baboons may impact predator populations.
Ecosystem Impact: soil aeration
Details on predation of gelada baboons are not available in the literature. Possible predators of these animals include large carnivores and raptors.
Life History and Behavior
Primates typically have complex social communication involving visual, tactical and accoustic symbols. Sometimes, chemical cues are also used.
Geladas use visual signals, such as facial expression and body posture, to communicate with one another. There are also visual signals associated with estrus, such as the reddening of the chest patch in females.
Geladas make a number of vocalizations.
In addition, tactile communication, between mates, between grooming partners, as well as between mothers and their young, can be important in maintaining social bonds.
Some chemical communication is apparently also present in this species, as males often smell the reddedned chest patch of estrus females.
Communication Channels: visual ; tactile ; acoustic ; chemical
Perception Channels: visual ; tactile ; acoustic ; chemical
A captive gelada is reported to have lived well over 30 years. Lifespan of these animals in the wild has not been reported, but is presumably less than that seen in captivity.
Status: captivity: 30+ (high) years.
Status: captivity: 27.0 years.
Status: wild: 20.0 years.
Status: captivity: 20.8 years.
Status: captivity: 28.0 years.
Lifespan, longevity, and ageing
Copulation is usually initiated by the female and occurs between the estrus females of a group and the group's male leader (Stammbach, 1987; Smuts, 1987).
Mating System: polygynous
Gelada baboons do not have a specific mating season, though it has been noted that the birth rate is higher during the rainy season. When a gelada female comes into estrus a ring of red beading develops in the naked patch on her chest and her ano-genital region swells visibly. The estrus cycles of females within a group are fairly synchronized, as are births. This may be due to social influence (Kawai, 1979).
Gestation length in gelada baboons is estimated at 5 to 6 months. Females generally give birth to one infant at a time and females with infants are anestrus (Smuts, 1987; Kawai, 1979). Lactation lasts for about 12 to 18 months. Females reach sexual maturity at about 4 or 5 years of age, but males do not become sexually mature until 5 or 7 years.
Breeding interval: It is possible for a female to produce young annually under good conditions.
Breeding season: Gelada baboons do not have a specific mating season, though it has been noted that the birth rate is higher during the rainy season.
Average number of offspring: 1.
Range gestation period: 5 to 6 months.
Range weaning age: 12 to 18 months.
Range age at sexual or reproductive maturity (female): 4 to 5 years.
Range age at sexual or reproductive maturity (male): 5 to 7 months.
Key Reproductive Features: iteroparous ; year-round breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; viviparous
Average birth mass: 464 g.
Average number of offspring: 1.
As in other primates, parental care is primarily the responsibility of females. Females must carry, groom, nurse and protect their offpspring until the young are independent. The role of males in the care of offspring is not well understood.
Parental Investment: pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female, Protecting: Female); pre-independence (Provisioning: Female, Protecting: Female); extended period of juvenile learning
Molecular Biology and Genetics
Barcode data: Theropithecus gelada
Below is a sequence of the barcode region Cytochrome oxidase subunit 1 (COI or COX1) from a member of the species.
See the BOLD taxonomy browser for more complete information about this specimen and other sequences.
-- end --
Download FASTA File
Statistics of barcoding coverage: Theropithecus gelada
Public Records: 3
Specimens with Barcodes: 4
Species With Barcodes: 1
The status of gelada baboons does not appear to be cause for concern at this point, yet because this is such an ecologically specialized species it has been included in the IUCN red Data Book and listed in appendix II of CITES, permitting only monitored trade between countries. Within Africa geladas are "permited to be hunted, killed, or collected only on government authority, but only providing it is in the national interest or for the purpose of science" (Dunbar, 1993: 582). Where geladas have been accused of raiding locally cultivated lands they are shot by farmers (Kawai, 1979). Within the Semien Mountain National Park, which is a conservation area, geladas are completely protected.
US Federal List: no special status
CITES: appendix ii
IUCN Red List of Threatened Species: least concern
Date Listed: 10/19/1976
Lead Region: Foreign (Region 10)
Where Listed: Entire
Population location: Entire
Listing status: T
For most current information and documents related to the conservation status and management of Theropithecus gelada , see its USFWS Species Profile
Relevance to Humans and Ecosystems
As human populations in Ethiopia and Eritrea grow, city boundries are expanding. Gelada baboons have been blamed for raids on cultivated lands, but many people believe the blame ill-placed. (Kawai, 1979. Jablonski, 1993).
Negative Impacts: crop pest
Past records show that gelada baboons were hunted for food by farmers during dry seasons (Jablonski, 1993).
Positive Impacts: food
|This article's lead section may not adequately summarize key points of its contents. (August 2013)|
The gelada (Theropithecus gelada), sometimes called the gelada baboon and bleeding-heart baboon, is a species of Old World monkey found only in the Ethiopian Highlands, with large populations in the Semien Mountains. Theropithecus is derived from the Greek root words for "beast-ape." Like its close relatives the baboons (genus Papio), it is largely terrestrial, spending much of its time foraging in grasslands.
Phylogeny and fossils
Since 1979, it has been customary to place the gelada in its own genus (Theropithecus), though some genetic research suggests this monkey should be grouped with its papionine (baboon) kin; other researchers have classified the species even farther distant from Papio. While Theropithecus gelada is the only living species of its genus, separate, larger species are known from the fossil record: T. brumpti, T. darti and T. oswaldi, formerly classified under genus Simopithecus. Theropithecus, while restricted at present to Ethiopia, is also known from fossil specimens found in Africa and the Mediterranean into Asia, including South Africa, Malawi, the Democratic Republic of the Congo, Tanzania, Uganda, Kenya, Ethiopia, Algeria, Morocco, Spain, and India, more exactly at Mirzapur, Cueva Victoria, Pirro Nord, Ternifine, Hadar, Turkana, Makapansgat and Swartkrans.
- Northern gelada, Theropithecus gelada gelada
- Eastern gelada, southern gelada or Heuglin's gelada, Theropithecus gelada obscurus
The gelada is large and robust. It is covered with buff to dark brown, coarse hair and has a dark face with pale eyelids. Its arms and feet are nearly black. Its short tail ends in a tuft of hair. Adult males have a long, heavy cape of hair on their backs. The gelada has a hairless face with a short muzzle that is closer to a chimpanzee's than a baboon's. It can also be physically distinguished from a baboon by the bright patch of skin on its chest. This patch is hourglass-shaped. On males it is bright red and surrounded by white hair; on females it is far less pronounced. However, when in estrus, the female's patch will brighten, and a "necklace" of fluid-filled blisters forms on the patch. This is thought to be analogous to the swollen buttocks common to most baboons experiencing estrus. In addition, females have knobs of skin around their patches. Geladas also have well developed ischial callosities. There is sexual dimorphism in this species: males average 18.5 kg (40.8 lb) while females are smaller, averaging 11 kg (24.3 lb). The head and body length of this species is 50–75 cm (19.7–29.5 in) for both sexes. Tail length is 30–50 cm (11.8–19.7 in).
The gelada has several adaptations for its terrestrial and graminivorous (grass-eating) lifestyle. It has small, sturdy fingers adapted for pulling grass and narrow, small incisors adapted for chewing it. The gelada has a unique gait, known as the shuffle gait, that it uses when feeding. It squats bipedally and moves by sliding its feet without changing its posture. Because of this gait, the gelada's rump is hidden beneath and so unavailable for display; its bright red chest patch is visible, though.
Range and ecology
Geladas are found only in the high grassland of the deep gorges of the central Ethiopian plateau. They live in elevations 1,800–4,400 m above sea level, using the cliffs for sleeping and montane grasslands for foraging. These grasslands have greatly spaced trees and also contain bushes and dense thickets. The highland areas where they live tend to be cooler and less arid than lowlands areas. Thus, the geladas usually do not experience the negative effects the dry season has on food availability. Nevertheless, in some areas, they do experience frost in the dry season, as well as hailstorms in the wet season.
Geladas are the only primates that are primarily graminivores and grazers – grass blades make up to 90% of their diet. They eat both the blades and the seeds of grasses. When both blades and seeds are available, geladas prefer the seeds. They also eat flowers, rhizomes and roots when available, using their hands to dig for the latter two. They also consume herbs, small plants, fruits, creepers, bushes and thistles. Insects can be eaten, but only rarely and only if they can easily be obtained. During the dry season, grasses are eaten less and herbs are preferred. Geladas consume their food more like ungulates than primates, and can chew their food as effectively as zebras.
Geladas are primarily diurnal. At night, they sleep on the ledges of cliffs. At sunrise, they leave the cliffs and travel to the tops of the plateaus to feed and socialize. When morning ends, social activities tend to wane and the geladas primarily focus on foraging. They will travel during this time, as well. When evening arrives, geladas exhibit more social activities before descending to the cliffs to sleep.
Geladas live in a complex multilevel society similar to that of the hamadryas baboon. The smallest and most basic groups are the reproductive units, which are made up of one to 12 females, their young and one to four males, and the all-male units, which are made up of two to 15 males. The next level of gelada societies are the bands which are made up of two to 27 reproductive units and several all-male units. Herds consist of up to 60 reproductive units that are sometimes from different bands and last for short periods of time. Communities are made of one to four bands whose home ranges overlap extensively. A gelada can typically live to around 20 years old.
Within the reproductive units, the females tend to be closely related and have strong social bonds. Reproductive units do split up if they get too large. While females have strong social bonds in the group, a female will only interact with at most three other members of her unit. Grooming and other social interactions among females usually occur between pairs. Females in a reproductive unit exist in a hierarchy. Higher-ranking females have more reproductive success and more offspring than lower-ranking females. Closely related females tend to have a similar hierarchical status. Females stay in their natal units for life; cases of females leaving are rare. Aggression is rare within a reproductive unit, being directed mostly towards members of other units. More often, the females start conflicts, but both males and females from both sides will join if the conflict escalates. Also, aggression within a reproductive unit is usually between females.
Males can remain in a reproductive unit for four to five years. While geladas have traditionally been considered to have a male-transfer society, many males appear to be likely to return and breed in their natal bands. Nevertheless, gelada males leave their natal units and try to take over a unit of their own. A male can take over a reproductive unit either through direct aggression and fighting or by joining one as a subordinate and taking some females with him to create a new unit. When more than one male is in a unit, only one of them can mate with the females. The females in the group together can have power over the dominant male. When a new male tries to take over a unit and overthrow the resident male, the females can choose to support or oppose him. The male maintains his relationship with the females by grooming them rather than forcing his dominance, in contrast to the society of the hamadryas baboon. Females accept a male into the unit by presenting themselves to him. Not all the females may interact with the male. Usually, one may serve as his main partner. The male may sometimes be monopolized by this female. The male may try to interact with the other females, but they usually are unresponsive.
Most all-male units consist of several subadults and one young adult, led by one male. A member of an all-male unit may spend two to four years in the group before attempting to join a reproductive unit. All-male groups are generally aggressive towards both reproductive units and other all-male units. As in reproductive units, aggression within all-male units is rare. As bands, reproductive units exist in a common home range. Within the band, members are closely related and between the units there is no social hierarchy. Bands usually break apart every eight to 9 years as a new band forms in a new home range.
Researchers from the University of the Free State (UFS) in South Africa, while observing gelada monkeys during field studies, discovered that the monkeys were capable of 'cheating' on their partners and covering up their 'infidelity'. A non-dominant male would mate surreptitiously with a female, suppressing their normal mating cries so as not to be overheard. If discovered, the dominant male would attack the miscreants in a clear form of punishment. It is the first time that evidence of the knowledge of cheating and fear of discovery has been recorded among animals in the wild. Dr Aliza le Roux of the Department of Zoology and Entomology at the university believes that dishonesty and punishment are not uniquely human traits, and that the observed evidence of this behaviour among gelada monkeys suggests that the roots of the human system of deceit, crime and punishment lie very deep indeed.
Reproduction and parenting
When in estrus, the female points her posterior towards a male and raises it, moving her tail to one side. The male then approaches the female and inspects her chest and genital areas. A female will copulate up to five times per day, usually around midday. Breeding and reproduction can occur at any time of the year, although some areas have birth peaks.
Most births occur at night. Newborn infants have red faces and closed eyes, and are covered in black hair. On average, newborn infants weigh 464 g. Females that have just given birth stay on the periphery of the reproductive unit. Other adult females may take an interest in the infants and even kidnap them. An infant is carried on its mother’s belly for the first five weeks, and thereafter on her back. Infants can move independently at around five months old. A subordinate male in a reproductive unit may help care for an infant when it is six months old. When herds form, juveniles and infants may gather into play groups of around 10 individuals. When males reach puberty, they gather into unstable groups independent of the reproductive units. Females sexually mature at around three years, but do not give birth for another year. Males reach puberty at around four or five years, but are usually unable to reproduce because of social constraints and have to wait until they are around eight to 10 years old. Average life span in the wild is 19 years.
Adult geladas use a diverse repertoire of vocalizations various purposes, such as; contact, reassurance, appeasement, solicitation, ambivalence, aggression and defense. The level of complexity of these vocalizations is thought to near that of humans. They sit around and chatter at each other, signifying to those around that they matter, in a way, to the individual "speaking". To some extent, calls are related to the status of an individual. In addition, females have calls signaling their estrus. Geladas communicate though gestures, as well. They display threats by flipping their upper lips back on their nostrils to display their teeth and gums, and by pulling back their scalps to display the pale eyelids. A gelada submits by fleeing or presenting itself.
In 2008, the IUCN assessed the gelada as Least Concern, although their population had reduced from an estimated 440,000 in the 1970s to around 200,000 in 2008. It is listed in Appendix II of CITES. Major threats to the gelada are a reduction of their range as a result of agricultural expansion, and shooting as crop pests. However, threats that once existed but no longer do are trapping for use as laboratory animals and shooting to obtain their capes to make items of clothing. As of 2008, proposals have been made for a new Blue Nile Gorges National Park and Indeltu (Shebelle) Gorges Reserve to protect larger numbers.
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