Papio ursinuschacma baboon

Geographic Range

The distribution of chacma baboons is primarily water limited. They are found throughout much of southern Africa. These baboons are found in the countries of Angola, Botswana, Mozambique, Namibia, South Africa, and Zambia.

This species is part of a complex of closely related African baboon species. We have an account of the whole genus under Papio. (Groves, 2001; Jolly, 1993; Melnick and Pearl, 1987; Nowak, 1999; Primate Info Net, 2002)

Habitat

Chacma baboons are found in wooded highlands, grassland steppe, and savanna habitats. (Jolly, 1993; Melnick and Pearl, 1987; Napier and Napier, 1985; Jolly, 1993; Melnick and Pearl, 1987; Napier and Napier, 1985)

Physical Description

These monkeys are sexually dimorphic in size and pelage characters. Head and body length is reportedly between 508 and 1.143 mm, with the tail adding an additional 456 to 711 mm to the total length. Males weigh from 26 to 31 kg and females around 15 kg. Animals found in the Kalahari desert are reported to be somewhat smaller than average. The average brain weight in adults of this species is 214.4 g. (Groves, 2001; Jolly, 1993; Nowak, 1999; Primate Info Net, 2002)

Males have large canine teeth, whereas the teeth of the females are much smaller. These animals have 32 teeth. The first lower premolar is modified and serves as a hone for the upper canine tooth. The skull of these baboons is large, and the face has a characteristic downward flex. The upper face is narrow and deeply constricted. The skin of the face is a dark, purple-black. The tail is bent. (Groves, 2001; Jolly, 1993; Napier and Napier, 1985)

Pelage of typical chacma baboons is dark brown to black dorsally, with the underparts and sides of the muzzle lighter. The fur on the hands and feet is black. The overall hair color is produced by individual hairs which are black with a single yellow-brown band. Light hairs typically have a black tip. Although males are not maned, as they are in anubis , hamadryas, and guinea baboons, they do have longish tufts of hair at the nape. The facial skin and the skin surrounding the ischial callosities is purplish-black. The natal pelage is black, and is replaced by adult-like fur around 6 months of age. (Groves, 2001; Jolly, 1993)

It should be noted that there is geographic variation in pelage coloration. Gray-footed baboons, an identifiable subgroup within the species, are found in the northeastern part of the species range. These baboons are slightly smaller than typical chacmas. They are distinguished from typical chacmas by the coloration of the fur, which is gray-buff. The fur on their hands and feet is the same grayish color as their arms, rather than the black seen in typical chacmas. Hairs show a different banding pattern than typical chacma baboons, with black tips and black rings. The post-orbital constriction is reduced in this variety of baboon. As in typical chacma baboons, the natal pelage is black, and this fur is replaced by the adult color around 6 months of age. (Jolly, 1993)

Transvaal baboons, another subgroup within P. ursinus, are known from a limited number of specimens collected near the region where gray-footed and typical chacma baboon ranges meet. It is not known whether this variety represents a stable baboon phenotype (and therefore a distinct population), or simply a few animals produced from hybridization of typical-chacma and gray-footed chacma baboons. Transvaal baboons are somewhat intermediate between the typical chacma and the gray-footed variety, supporting the hypothesis that they may represent hybrids of the other forms of chacma baboons. In fur color and hair-banding pattern they resemble gray-footed baboons. However, they possess black feet, like typical chacmas. In size and cranial shape, these baboons resemble typical chacmas. Nothing is known about the natal pelage of these baboons. (Jolly, 1993)

  • Range mass
    15 to 31 kg
    33.04 to 68.28 lb
  • Range length
    508 to 1,143 mm
    20.00 to in

Reproduction

Reproductive behavior in P. ursinus is closely tied to social organization. When these animals live in multi-male, multi-female troops, there is the potential for any male to mate with any female. Because of this, males in multi-male troops compete fiercely for access to sexually receptive females. In general, a male’s ability to consort with a female and exclude other males from access to her is related to the male’s ability to compete with other males. There is therefore a correlation between male dominance rank within the troop and mating success. Larger, younger, and stronger males have a distinct advantage in this type of competition. (Melnick and Pearl, 1987)

However, as in many social animals, there are other factors which affect a male’s mating success. For example, in P. anubis males may form alliances with other males, which can subvert the normal dominance hierarchy. Two males, neither of whom can dominate a third male alone, may join forces and together, as a coalition, these males may succeed in securing access to a sexually receptive female. Such coalitions may occur in chacma baboons, although research has yet to address this behavior in P. ursinus. (Melnick and Pearl, 1987; Smuts, 1987a)

In anubis baboons, males also follow a strategy of developing "friendships" with females, which enhances their opportunities to mate. In these friendships, males groom, share food, and have strong affiliative ties with particular females and their offspring. It is common for males to defend their female friends during agonistic encounters with other females, and with other males. These associations are not confined to the period during which females are sexually receptive, but span the entire gamut of the female’s reproductive life—including pregnancy, lactation, and time spent cycling. Females tend to exhibit a preference for mating with their male friends, and therefore make consortships with their male friends more likely. In addition, because females prefer their friends as mates, they are more likely to cooperate with them in the maintenance of a consortship than they are to cooperate with other, less favored, males. These types of long-term friendships may also exist in chacma baboons, although further research is needed to clarify this point. (Melnick and Pearl, 1987; Smuts, 1987b; Smuts, 1987a)

Females clearly exert some mate choice. In addition to having sexually proceptive behavior, in which the female makes some decision about which males she will mate with by presenting her hindquarters to those males, they may refuse to mate with some males. When new males immigrate into a troop, females may help or hinder their chances of success by developing affiliative relationships with the immigrating males. In this way, females may choose which males will be in their potential mating pool. (Smuts, 1987b; Smuts, 1987a)

Reproduction in P. ursinus is related to the social structure of this species. The social structure is somewhat variable, with the majority of animals living in multi-male, multi-female troops reminiscent of anubis baboons. In some cases, however, the social structure resembles that of hamadryas baboons, with single males controlling a group of females. Mating in multi-male, multi-female troops is polygynandrous, with both males and females mating with multiple partners. Mating in One Male Units (OMUs) is necessarily polygynous. (Hamilton III and Bulger, 1992; Melnick and Pearl, 1987)

Most matings in multi-male, multi-female troops occur during consortships. Consortships arise when a male, through aggression toward potential rivals, is able to maintain exclusive sexual access to a female. Females may consort with multiple males during the periovulatory period, although they consort with only one male at a time. Because it is apparently easier for a male to maintain exclusive access to a female if the female is cooperative, there is a significant amount of female mate choice, with females preferring some partners over others. (Hamilton III and Bulger, 1992; Hrdy and Whitten, 1987; Melnick and Pearl, 1987; Smuts, 1987a)

In OMUs, males do not alter their general behavior toward females, with the exception of mating with them mostly when the females are close to ovulation. Males in OMUs do not consort with females. If another adult male enters the group, however, this behavior changes drastically, with typical competition between males and consortships developing. (Hamilton III and Bulger, 1992)

Females characteristically have an estrous cycle of 31 to 35 days in length. There is a noticeable menstrual flow for approximately three days per cycle if the female does not conceive. During the period around ovulation, the perineal skin of the female swells, alerting the males to her potentially fertile condition, and enhancing her attractiveness to them. Females are sexually receptive and mate throughout their cycle, but copulations peak at midcycle when the female is likely to ovulate. Mating is initiated by the female, who presents her hindquarters to the male. Like hamadryas baboons, chacma males are serial mounters. A male will mount a female several times, with 1 to 20 thrusts per mount, before ejaculating. When the female is cycling, mating frequency can be as high as 7 to 12.2 copulations per hour. Mating does not occur during pregnancy. (Hrdy and Whitten, 1987)

Gestation is probably similar to that of other Papio species, which ranges from 175 to 180 days. Females give birth to a single offspring. The newborn of P. anubis weighs 1068 g on average, and the young of chacma baboons are probably similar in size. The neonate has a black coat, making it easy to distinguish from older infants. An infant is completely dependent upon its mother for the first few months, until it begins to eat solid food and is able to walk on its own. Females have an interbirth interval ranging from 18 to 24 months. As in other baboons, it is likely that this interval varies according to a number of factors. In anubis baboons, females who are older or have a higher rank tend to have shorter interbirth intervals. Interbirth interval is also shorter if an infant dies before weaning. (Hrdy and Whitten, 1987; Melnick and Pearl, 1987; Nicolson, 1987; Nowak, 1999; Smuts and Nicolson, 1989)

Data on the nursing period in this species are scanty. However, it is likely that timing and patterns resemble other members of the genus. Weaning typically occurs in P. anubis around 420 days of age. Lactation is a huge cost for adult females, and has been implicated in dramatic weight reductions in anubis females. Lower ranking and younger females probably take longer to recover adequate body weight to reproduce than do older, dominant females, due to their reduced access to prime feeding sites. This would explain their longer interbirth intervals. (Bercovitch, 1987; Smuts and Nicolson, 1989)

The onset of puberty and attainment of adult size are variable and are associated with nutrition levels. For example, in P. anubis populations where baboons are known to raid human crops, and to thereby secure greater access to nutrients than naturally foraging animals, puberty can occur much earlier. The effect of nutrition on growth in P. anubis is so strong that as little as 15 to 16 weeks of dietary variation in newborns can have lasting effects on overall rates of female growth, absolute adult weight, and age at menarche. It is reasonable to assume that chacma baboons are similarly affected. (Strum, 1991)

In P. ursinus females reach sexual maturity at approximately 3 years of age. Male sexual maturity occurs around 5 years of age. Within about a year, these animals will reach full size, or experience their first birth. There are no data available regarding the maturation of testicles or sperm production in this species. However, because chacma baboons have a variable mating system, and mating system differences have been implicated as the evolutionary cause of differences in the schedule of sexual maturation between anubis and hamadryas baboons, such data would be very interesting. (Hrdy and Whitten, 1987; Jolly and Phillips-Conroy, 2003; Melnick and Pearl, 1987)

  • Breeding interval
    These animals can breed every 1.5 to 2 years.
  • Breeding season
    Mating can occur throughout the year.
  • Range number of offspring
    1 (low)
  • Average number of offspring
    1
  • Average time to independence
    12 months
  • Average age at sexual or reproductive maturity (female)
    3 years
  • Average age at sexual or reproductive maturity (male)
    5 years

Most parental care is performed by the female. Females nurse, groom, and play with their offspring. Females express different patterns of infant care, often associated with rank and age. In yellow baboons, higher-ranking females tend to be more "permissive" in their parenting than lower ranking females, who tend to me more nervous and "restrictive," preventing their offspring from moving away from them. (Altmann, 1980; Melnick and Pearl, 1987; Nicolson, 1987)

There does not seem to be cooperative care of offspring among females in P. ursinus, but it is not uncommon for females other than the mother to groom an infant, sometimes providing allomaternal care to the infant. As in other baboons, subadult and juvenile females who have not yet reproduced themselves are most likely to exhibit allomaternal behavior. As is the case for all baboons, infants are very attractive to other members of the social group, and are the focus of a great deal of investigation and attention, especially while they are still displaying their black natal coat. In extreme cases, female anubis baboons may kidnap the offspring of other females. Lower-ranking females are more often subject to this extreme form of harassment than are higher-ranking females. Other factors known to affect the incidence of allomaternal behavior in other species include the infant’s age, and relatedness of the allomother to the mother and infant. (Altmann, 1980; Melnick and Pearl, 1987; Nicolson, 1987)

Males have complex relationships with infants and juveniles, which in some cases may be a form of parental care. In other savanna baboon species, males are known to carry, protect, share food (especially meat), groom, and play with, the offspring of their female friends. Because they are more likely to mate with their female friends than they are with other females, these infants and juveniles are more likely to be their own offspring than are other immature animals within the troop. This behavior, therefore, can be interpreted as paternal. Although not specifically reported for chacma baboons, it is likely that this behavior does occur in this species. (Melnick and Pearl, 1987; Stein, 1984; Whitten, 1987)

However, it should be noted that the relationship between adult males baboons and immature animals may be more complex than this. There may be some form of reciprocity involved. Adult males will often carry infants during tense interactions with other adult males. This carrying can be initiated either by the adult male or by the infant. Such contact with an infant during agonistic encounters may have the effect of inhibiting aggression by other males. The favors bestowed upon an infant used as a buffer may therefore be a form a "payback" from the adult male. However, since the tendency to use an infant as an agonistic buffer is related to familiarity with the infant, and in baboons and macaques familiarity with an infant is associated with the probability of paternity, it is impossible to separate the nepotism from the reciprocity of such interactions. (Stein, 1984)

  • Parental Investment
  • altricial
  • pre-fertilization
    • provisioning
    • protecting
      • female
  • pre-hatching/birth
    • provisioning
      • female
    • protecting
      • female
  • pre-weaning/fledging
    • provisioning
      • male
      • female
    • protecting
      • male
      • female
  • pre-independence
    • provisioning
      • male
      • female
    • protecting
      • male
      • female
  • post-independence association with parents
  • extended period of juvenile learning
  • inherits maternal/paternal territory
  • maternal position in the dominance hierarchy affects status of young

Lifespan/Longevity

A chacma baboon (P. ursinus) is reported to have lived 45 years in captivity. It is unlikely that many individuals live this long in the wild. (Nowak, 1999)

Behavior

Members of a troop or OMU travel, forage, and sleep together. An average troop may be comprised of 20 to 80 animals. Home ranges between 910 and 3,370 ha have been reported. The daily range of a troop varies between 1,609 and 14,484 m. This makes both the home range size and the daily range among the largest for savanna baboon species. The movements of a troop may be limited by the availability of appropriate sleeping locations and appropriate watering sites. Because the troop beds down on rocks/cliffs, activity of the troop must be coordinated so that one of a set number of sleeping sites can be reached by nightfall. (Hamilton III and Bulger, 1992; Melnick and Pearl, 1987; Primate Info Net, 2002)

Chacma baboons are quadrupedal, mainly terrestrial primates. They are highly social animals, with a complex multi-male, multi-female social structure. In some cases, one-male units (OMUs) may form within the broader multimale multi-female society, resulting in substantial differences in behavior. (Hamilton III and Bulger, 1992; Melnick and Pearl, 1987)

All males emigrate from their natal troops, with 100 percent of males emigrating prior to the time that they reach full adult size. Upon settling in a new troop, males must establish themselves in the male dominance hierarchy of that troop. This typically involves aggressive behavior between males, with the "winner" of an encounter establishing dominance over the "loser." Males do not maintain long-term bonds with their male kin, as is seen in hamadryas baboons. (Melnick and Pearl, 1987; Primate Info Net, 2002; Pusey and Packer, 1987; Walters, 1987)

Because males do not maintain life-long social ties with their kin, it is female kinship that forms the core and stability of P. ursinus society. Because females of this species do not emigrate from their natal groups, female kin have life-long associations. Within a troop of chacma baboons, there is a dominance hierarchy of matrilines which is very stable over time. In general, an individual female occupies a place in the dominance hierarchy immediately below her mother and her younger sisters. Dominance relationships appear to develop from infancy, when maternal kin intervene in encounters with other baboons, and through the differential treatment of the young of higher-ranking females by unrelated animals. Within a matriline, the dominance relationships of sisters are the inverse of birth order. (Melnick and Pearl, 1987)

Female kin behave differently toward one another than do unrelated animals. Females are more likely to aid their kin during disputes than they are to become involved in disputes of unrelated individuals. These relationship can extend over multiple generations, with females aiding not only their own offspring, and aunts aiding nieces, but grandmothers aiding their granddaughters. (Melnick and Pearl, 1987; Smuts, 1987b)

The female dominance hierarchy is not continually challenged by the arrival of new females in the troop, which probably allows for the stability of female dominance relationships over time. Perhaps because relatedness of females within troops is inherently higher than the relatedness of females between troops, female baboons are likely to take the lead in aggressive encounters with other troops of baboons. Females are apparently acting to defend their food resources in such encounters. (Melnick and Pearl, 1987)

An interesting characteristic of chacma baboon social structure is the prevalence of OMUs. Although OMUs have been reported for other species of savanna baboons (anubis and yellow baboons), they are not common, and tend to be somewhat short-lived. However, in P. ursinus, this type of social organization is commonly seen. They are especially common in populations inhabiting the mountains of eastern South Africa. (Hamilton III and Bulger, 1992)

OMUs can form on the backdrop of multi-male, multi-female troops in a variety of ways. The fission of a group containing a single male with multiple females from a larger group can produce an OMU. An OMU may form through stochastic changes in demography or environmentally induced changes in demography. Also, OMUs can form by the temporary separation of a single male and several females on daily foraging marches. (Hamilton III and Bulger, 1992)

Regardless of how OMUs form, certain differences in behavior of animals in these social groups emerge. These differences are apparent in foraging patterns, sexual behaviors, intergroup relations, intragroup relations, and the general behavior patterns of males. (Hamilton III and Bulger, 1992)

With regard to feeding, the animals in an OMU tend to utilize small food patches, especially fruiting trees. Within these fruiting trees, all members of the OMU are able to forage. Within a particular tree, an OMU will exhaust the available fruit before moving on to other feeding locations. In contrast, in multi-male troops, some animals of the troop are excluded from such food sources. A maximum of 17 of the 61 baboons in one such troop was seen feeding in the same tree at a single time. Although more members of the troop may feed in the tree sequentially, the members of the multi-male troops typically leave the fruiting tree while the fruit is still in surplus. (Hamilton III and Bulger, 1992)

Additional differences in feeding have been noted. Multi-male troops of chacma baboons often forage on fresh grass, Cypress crowns, and the tubers of aquatic plants, especially those of Nymphaea caerulea, a water lily. OMUs avoided these pants, and focused their foraging on the fruits of the Kigelia pinnata tree, the green seeds of Acacia nigrens, and figs (Ficus sycomorus and Ficus burki). These food sources were ignored by multi-male groups. (Hamilton III and Bulger, 1992)

Within multi-male troops of chacma baboons, males typically form consortships with females during the female estrus period. However, in OMUs, no consortships were noted. This is a significant difference in mating behavior. It would be interesting to know if the pattern and timing of copulations is different in the different types of social groups, however, no data addressing this appear to exist. (Hamilton III and Bulger, 1992; Melnick and Pearl, 1987)

The dynamics of interactions within the social group also differ in OMUs compared to the more common multi-male troop. Within multi-male troops, there is a great deal of aggression between females. Females typically bite one another on the tail, and many females in multi-male troops exhibit chronic tail lesions resulting from these bites. In an OMU, females do not exhibit these tail lesions. Males actively manage female movements and interactions, much as male hamadryas baboons are known to do. When the male took a vigilant stand away from the rest of the OMU, female conflicts often erupted, indicating that the presence of the male was important in suppressing female aggression. (Hamilton III and Bulger, 1992)

Unlike hamadryas baboon females, chacma females seem to be less responsive to the OMU male. Female chacma baboons do not respond to male stares. This may be because the male chacma in an OMU does not herd the females as aggressively as does a hamadryas male, and does not bite their necks as a hamadryas male would. However, if females stray too far from the rest of the group, the chacma baboon OMU male will herd the female back into the fold. (Hamilton III and Bulger, 1992; Kummer, 1968; Stammbach, 1987)

Some have suggested that, like hamadryas baboons, the OMUs of chacma baboons can be described as cross-bonded. Rather than having close social ties with other females, the females of the OMU appear to have the greatest amount of interaction and the closest social relationship with the male. This is especially interesting because unlike hamadryas baboons, where females emigrate from their natal groups, disrupting their relationships with female kin, female chacma baboons have life-long interactions with female kin. Female kinship forms the basis for the organization of the multi-male, multi-female troops in this species. A departure for this within OMUs represents an extreme difference in the basic fabric of social bonding typical of these animals. (Hamilton III and Bulger, 1992; Kummer, 1968; Stammbach, 1987; Swedell, 2002)

The male in OMUs may behave differently than his counterparts in multi-male troops during intergroup encounters. First, the chacma male in an OMU will avoid other baboon groups. There is an increase in wariness reported for these males, with males spending a great deal of their time scanning the horizon, possibly searching for other males, other social groups, or predators. Males will "peer" into other groups to monitor the activity of animals there. This level of vigilance is not common of males in multi-male troops. (Hamilton III and Bulger, 1992)

Second, the OMU male may actively approach and pursue lone males who come close to his group, even if it involves leaving the group’s territory to do so. In contrast, the alpha, or highest ranking, male in multi-male troops seldom leaves group space to approach an intruder. The OMU male may also enter other social groups to "preemptively" chase other males who reside in those groups. Males in multi-male troops never enter other groups to harass males residing there. The only time males from a multi-male troop enter another troop is when low-ranking or subadult males temporarily enter another troop as part of their evaluation of where to settle permanently. (Hamilton III and Bulger, 1992)

Behavior toward females is also different between OMU males and multi-male troop males during encounters with other groups. Multi-male troop males typically chase females during intergroup encounters. Males from OMUs do not do this. (Hamilton III and Bulger, 1992)

Another interesting facet of baboon behavior pertains to the location and spacing of different age and sex classes during the movements of baboon troops. Interest in this aspect of chacma behavior has been generated largely by the observation that forward positioning in a troop may be quite dangerous to the animals found there. For example, lions have been known to lie in wait at water holes, preparing to ambush the unsuspecting animals who wander down to the shore for a drink. For baboons, this would mean that animals at the front of the troop, arriving first at the water hole, would be more likely to fall victim to predation than animals who "hang back" in the procession. (Rhine and Tilson, 1987)

A forward tendency of adult males has been reported in P. ursinus, P. anubis, and P. cynocephalus. Research on chacma baboons has shown that this forward tendency increases when approaching a water hole. It is unclear whether the adult males are placing themselves in front, or whether this forward positioning is caused by other animals staying back. It is likely that animals position themselves within the group based upon their own level of apprehension. Juveniles, who are inexperienced and small, are more likely to be afraid of entering clearings, or approaching new places, and are therefore likely to stay back and let others go first. (Rhine and Tilson, 1987)

  • Range territory size
    910,00 to 3,37000 m^2

Home Range

Home ranges between 910 and 3,370 ha have been reported. The daily range of a troop varies between 1,609 and 14,484 m. (Melnick and Pearl, 1987)

Communication and Perception

As in all highly social species, communication is varied and complex. Chacma baboons utilize visual signals and gestures, vocalizations, and tactile communication. (Primate Info Net, 2002)

Visual signals include social presenting, in which a female or juvenile displays its hind quarters to a male. It can also be done by a female who has approached another female with her black infant. This submissive signal differs from sexual presenting (which females do to elicit copulation), and is often accompanied by lip smacking. Staring is a threat behavior, the effect of which is enhanced by the differently colored fur in the region of the eye which is revealed when the baboon stares. Eyebrow raising is a similar aggressive gesture. Canine tooth display through a tension yawn is another threatening gesture. It is performed by lower-raking males toward higher-ranking males who are consorting with estrus females or who possess meat. Male baboons who are close to one another can use tooth grinding to threaten one another. Baboons who are being threatened use rapid glances in the opposite direction to break tension. Adult males who are guarding mates sometimes sit with their erect penis is plain view. This penile display communicates the male’s presence to other males. (Primate Info Net, 2002)

Teeth chattering and lipsmacking, although not technically vocalizations, are auditory cues of reassurance, often performed by a dominant animal when another is presenting to him. A female may also lipsmack when approaching a mother and her black infant. (Primate Info Net, 2002)

Vocalizations made by chacma baboons include a two-phase bark, or "wahoo" call, which adult males direct toward feline predators or toward other males. It is thought to communicate the presence of the male and his arousal. This call may be preceded by grunting, a soft threat call. Screeching is common during aggressive encounters, and can be made by any age or sex class. It appears to inhibit aggression. Subadult and adult baboons produce a yakking call when retreating from a threatening animal. This call is often accompanied by a grimace of fear. A shrill bark is produced by all except adult males to indicate alarm, especially due to sudden disturbances. Finally, rhythmic grunting may be produced by all chacma baboons except infants when they wish to signal reassurance to another animal. (Primate Info Net, 2002)

Juveniles and infants produce some vocalizations unique to their age class. These include chattering, which is a nasal, grunt-like call emited during play. They also produce an ick-ooer sound which communicates a low level of distress. (Primate Info Net, 2002)

Adult females of this species produce a vocalization during copulation called a muffled growl. The mouth is closed, and the cheeks expand and contract during this call. (Primate Info Net, 2002)

Tactile communication is common in cercopithecines. Social grooming is used to reinforce social bonds, as well as to remove parasites and debris from the fur. Social mounting is a reassurance behavior. Anubis baboons also perform a friendly nose-to-nose greeting. (Primate Info Net, 2002)

Chemical communication has not been reported for this species. However, female anubis baboons are known to produce aliphatic acids when they are sexually receptive. These acids are thought to enhance a female’s sexual attractiveness. It is possible that female chacma baboons also produce these acids. (Hrdy and Whitten, 1987)

Food Habits

Chacma baboons are known to eat fruits, including Kigelia pinnata fruit and figs from both Ficus sycomorus and Ficus burki. They also eat leaves, including the crowns of Cypress trees, tree gums, insects, eggs, seeds, including the green seeds of Acacia nigrens, flowers, water lilies (Nymphaea caerulea), grass, rhizomes, corms, roots, tubers, and small vertebrates. (Hamilton III and Bulger, 1992; Nowak, 1999; Primate Info Net, 2002)

One feeding adaptation thought to be shared by all baboons is the ability to subsist on a relatively low quality diet. Baboons can subsist on grasses for extended periods of time. This allows them to exploit dry terrestrial habitats, like deserts, semideserts, steppes, and grasslands. (Nowak, 1999)

  • Animal Foods
  • birds
  • mammals
  • reptiles
  • eggs
  • carrion
  • insects
  • terrestrial non-insect arthropods
  • Plant Foods
  • leaves
  • roots and tubers
  • wood, bark, or stems
  • seeds, grains, and nuts
  • fruit

Predation

Two predator species are known for chacma baboons in Botswana: leopards, and lions. Predation rate has been estimated at 9 percent of the population per year. Of these animals, 18 percent are thought to be infants, 18 percent juveniles, and 13 percent adult males. A full 50 percent of predation deaths are of adult females. (Cheney and Wrangham, 1987; Rhine and Tilson, 1987)

Risk of predation may have an influence on how animals organize themselves within a moving group of chacma baboons. Animals who are less able to defend themselves from predators, or who have greater fear of predators, may locate themselves toward the rear of a groups approaching potentially dangerous areas, such as water holes. Also, these vulnerable individuals may by virtue of greater fear, may end up at the front of the group as it retreats from a predator. (Rhine and Tilson, 1987)

Baboons have been known to attack leopards. Males, with their elongated canines, can inflict great damage on potential predators. It may be that the high percentage of females, infants, and juveniles taken by predators is related to a preference by predators for these less dangerous prey items. (Melnick and Pearl, 1987; Nowak, 1999)

Ecosystem Roles

Because chacma baboons are prey items, they form an important link in local food webs, making nutrients they obtain from plants and small animals available to larger animals. They dig for tubers, roots, rhizomes and corms, so it is likely that these animals help to aerate the soil where they forage. Also, it is likely that they play some role in dispersing seeds they eat. (Nowak, 1999)

Economic Importance for Humans: Positive

Chacma baboons are very interersting animals, and provide a great deal of entertainment to people who visit them in zoos. Some of these animals have been used in medical research. (Williams-Blangero, et al., 1990)

  • Positive Impacts
  • research and education

Economic Importance for Humans: Negative

All baboons can be terrible crop pests, as they are not particularly shy of humans. They are large animals which can be aggressive when confronted. (Nowak, 1999)

  • Negative Impacts
  • injures humans
    • bites or stings
  • crop pest

Conservation Status

Chacma baboons are not listed as threatened or endangered.

Contributors

Nancy Shefferly (author), Animal Diversity Web.

Glossary

Ethiopian

living in sub-Saharan Africa (south of 30 degrees north) and Madagascar.

World Map

acoustic

uses sound to communicate

altricial

young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

carrion

flesh of dead animals.

chaparral

Found in coastal areas between 30 and 40 degrees latitude, in areas with a Mediterranean climate. Vegetation is dominated by stands of dense, spiny shrubs with tough (hard or waxy) evergreen leaves. May be maintained by periodic fire. In South America it includes the scrub ecotone between forest and paramo.

chemical

uses smells or other chemicals to communicate

diurnal
  1. active during the day, 2. lasting for one day.
dominance hierarchies

ranking system or pecking order among members of a long-term social group, where dominance status affects access to resources or mates

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

fertilization

union of egg and spermatozoan

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

nomadic

generally wanders from place to place, usually within a well-defined range.

omnivore

an animal that mainly eats all kinds of things, including plants and animals

polygynandrous

the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.

polygynous

having more than one female as a mate at one time

scrub forest

scrub forests develop in areas that experience dry seasons.

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

sexual ornamentation

one of the sexes (usually males) has special physical structures used in courting the other sex or fighting the same sex. For example: antlers, elongated tails, special spurs.

social

associates with others of its species; forms social groups.

soil aeration

digs and breaks up soil so air and water can get in

tactile

uses touch to communicate

temperate

that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).

territorial

defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement

tropical

the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.

tropical savanna and grassland

A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.

savanna

A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.

temperate grassland

A terrestrial biome found in temperate latitudes (>23.5? N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.

visual

uses sight to communicate

viviparous

reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

year-round breeding

breeding takes place throughout the year

References

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