Animal Diversity Web

Ge­o­graphic Range

Papio anu­bis is the most broadly dis­trib­uted ba­boon species, rang­ing through most of cen­tral sub-Sa­ha­ran Africa. Iso­lated pop­u­la­tions occur within the Sa­ha­ran re­gion.

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; Nowak, 1999; Pri­mate Info Net, 2000)

• Biogeographic Regions
• ethiopian
  • native

Habi­tat

Anu­bis ba­boons are found in sa­van­nah, grass­land steppe, and rain­for­est habi­tats. (Jolly, 1993; Mel­nick and Pearl, 1987; Nowak, 1999; Pri­mate Info Net, 2000)

• Habitat Regions
• tropical
• terrestrial

• Terrestrial Biomes
• desert or dune
• savanna or grassland
• forest
• rainforest
• scrub forest

• Other Habitat Features
• agricultural

Phys­i­cal De­scrip­tion

These mon­keys are highly sex­u­ally di­mor­phic in size and pelage char­ac­ters. Males weigh around 25 kg and fe­males around 14 kg, with some ge­o­graphic vari­a­tion in av­er­age size. The head and body of the av­er­age male mea­sures 760 mm, with the tail adding an ad­di­tional 560 mm. Fe­males are smaller, with an av­er­age head and body mea­sure­ment of 600 mm and an av­er­age tail length of 480 mm. Males have large ca­nine teeth, whereas the teeth of the fe­males are much smaller. Pelage is char­ac­ter­is­ti­cally a dark, olive-gray. This over­all color is pro­duced by hairs with 1 to 2 al­ter­nat­ing pairs of black and yel­low-brown rings. Males pos­sess a large mane, re­stricted to the an­te­rior por­tion of the body, and grad­ing into the shorter body hair to­ward the rear. Fe­males lack a mane. (Groves, 2001; Jolly, 1993; Mel­nick and Pearl, 1987; Napier and Napier, 1985; Nowak, 1999; Pri­mate Info Net, 2000)

The skin of the face and around the is­chial cal­losi­ties is dark gray to black in both sexes. The bare area of the rump is much smaller in this species than in Papio hamadryas or Papio papio. Un­like some species of ba­boons, the nos­trils of P. anu­bis point for­ward. The head is flat on top, help­ing to dis­tin­guish this species from Papio cyno­cephalus which has a promi­nent crest on the top of the head. The first quar­ter of the tail is car­ried erect, being held straight up­ward, with the re­main­der of the tail falling down limp, giv­ing the tail a bro­ken ap­pear­ance. The natal pelage is black, but this fur is re­placed by the typ­i­cal olive-gray by about 6 months of age. (Groves, 2001; Jolly, 1993; Napier and Napier, 1985; Nowak, 1999)

The skull of males has heavy ridges of bone on both sides of the nose, and a promi­nent rounded bar above the or­bits. There is a sagit­tal crest and often a nuchal crest. Mo­lars are large, and the first lower pre­mo­lar has been mod­i­fied into a hone for the upper ca­nine. These pri­mates have 32 teeth. (Al­berts and Alt­mann, 2001; Groves, 2001; Jolly, 1993; Mel­nick and Pearl, 1987; Nowak, 1999)

• Other Physical Features
• endothermic
• homoiothermic
• bilateral symmetry

• Sexual Dimorphism
• male larger
• ornamentation

• Range mass

  14 to 25 kg

  30.84 to 55.07 lb

• Range length

  480 to 760 mm

  18.90 to 29.92 in

Re­pro­duc­tion

Re­pro­duc­tive be­hav­ior in P. anu­bis is closely tied to so­cial or­ga­ni­za­tion. Be­cause these an­i­mals live in multi-male, multi-fe­male troops, there is the po­ten­tial for any male to mate with any fe­male. This re­sults in fierce com­pe­ti­tion be­tween males 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. (Smuts, 1987a)

How­ever, as in many so­cial an­i­mals, there are other fac­tors which af­fect a male’s mat­ing suc­cess. For ex­am­ple, 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 are rec­i­p­ro­cal, and typ­i­cally occur be­tween pairs of older males who are well ac­quainted with one an­other through mu­tual tenure in a troop. (Mel­nick and Pearl, 1987; Smuts, 1987a)

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. (Mel­nick and Pearl, 1987; Smuts, 1987a)

The pro­longed pe­riod of sex­ual re­cep­tiv­ity of fe­males in this species is typ­i­cal of pri­mates liv­ing in multi-male, multi-fe­male so­cial groups. Fe­males in monog­a­mous or polyg­y­nous species are typ­i­cally re­cep­tive for a very short time around ovu­la­tion. In P. anu­bis, fe­males mate with a va­ri­ety of males over a pe­riod of 15 to 20 days. Such mul­ti­ple mat­ings are not nec­es­sary to en­sure fer­til­iza­tion, and may func­tion to con­fuse the ac­tual pa­ter­nity of the fe­male’s off­spring. This may help to mit­i­gate in­fan­ti­ci­dal ten­den­cies of males. (Hrdy and Whit­ten, 1987; Mel­nick and Pearl, 1987)

Fe­males exert some mate choice in this species. By mak­ing con­sortships eas­ier or more dif­fi­cult for males, fe­males can exert some con­trol over whom they mate with. Also, fe­males can make it eas­ier or more dif­fi­cult for a given male to im­mi­grate into the troop, in­flu­enc­ing the pool of males from which they may choose mates.

Mat­ing is ini­ti­ated by the fe­male, who pre­sents her hindquar­ters to the male. The male mounts the fe­male and thrusts about 6 times, then ejac­u­lates. Mat­ings are prob­a­bly quick be­cause of the in­tense in­ter­male com­pe­ti­tion for ac­cess to sex­u­ally re­cep­tive fe­males. (Hrdy and Whit­ten, 1987; Mel­nick and Pearl, 1987; Smuts, 1987b; Smuts, 1987a)

• Mating System
• polygynandrous (promiscuous)

Re­pro­duc­tion in P. anu­bis is re­lated to the so­cial struc­ture of this species. Anu­bis ba­boons live in multi-male, multi-fe­male troops. Mat­ing is polyg­y­nan­drous, with both males and fe­males mat­ing with mul­ti­ple part­ners. Most mat­ings 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 while they are sex­u­ally re­cep­tive, 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)

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, and aliphatic acids are pro­duced, alert­ing the males to her po­ten­tially fer­tile con­di­tion, and en­hanc­ing her at­trac­tive­ness to them. Fe­males are typ­i­cally re­cep­tive for 15 to 20 days per cycle. (Hrdy and Whit­ten, 1987; Mel­nick and Pearl, 1987)

Ges­ta­tion lasts about 180 days, after which the fe­male gives birth to a sin­gle off­spring, weigh­ing ap­prox­i­mately 1068 g. 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 12 to 34 months. This in­ter­val varies ac­cord­ing to a num­ber of fac­tors. 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. (Bercov­itch, 1987; Hrdy and Whit­ten, 1987; Mel­nick and Pearl, 1987; Smuts and Nicol­son, 1989; Strum, 1991)

Wean­ing typ­i­cally oc­curs around 420 days of age. Lac­ta­tion is a huge cost for adult fe­males, and typ­i­cally causes a re­duc­tion in fe­male weight. Lower rank­ing and younger fe­males prob­a­bly take longer to re­cover ad­e­quate body weight to re­pro­duce than do older, dom­i­nant fe­males, ex­plain­ing their longer in­ter­birth in­ter­vals. (Bercov­itch, 1987; Mel­nick and Pearl, 1987; Smuts and Nicol­son, 1989)

The onset of pu­berty and at­tain­ment of adult size is highly vari­able and is as­so­ci­ated with nu­tri­tion lev­els. In 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. In such food-sup­ple­mented pop­u­la­tions, males at­tain adult body weight be­tween 7 and 8 years. Fe­males reach full size by 6.5 years. In con­trast, in nat­u­rally for­ag­ing pop­u­la­tions, males do not reach full adult size until they are 7 to 10 years old, and fe­males do not reach adult weight until they are 7 to 8 years old. The ef­fect of nu­tri­tion on growth 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. (Strum, 1991)

In nat­u­rally for­ag­ing pop­u­la­tions, pu­berty oc­curs be­tween the ages of 5 and 6 years in fe­males, and is sig­naled by menar­che, or in some cases, first preg­nancy. In males, pu­berty be­gins around 6.6 years of age, when body size be­gins to in­crease rapidly, third mo­lars erupt, and ca­nine teeth fully erupt. Changes in male body size in­clude in­creases in mus­cu­lar­ity, which give these an­i­mals a broader pro­file. The mane of males also be­gins to de­velop, con­tribut­ing to the in­crease in shoul­der size. Cor­re­lated with these changes in body size, male anu­bis ba­boons un­dergo an in­crease in tes­tic­u­lar vol­ume. Like human males un­der­go­ing pu­berty, male anu­bis ba­boons are also re­ported to un­dergo a break in their voices around this time, even­tu­ally lead­ing to a deeper sound­ing alarm-bark. Males typ­i­cally em­i­grate from their natal troop just after these changes are com­pleted. (Jolly and Phillips-Con­roy, 2003; Mel­nick and Pearl, 1987; Strum, 1991; Wal­ters, 1987)

• Key Reproductive Features
• iteroparous
• year-round breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual
• fertilization
• viviparous

• Breeding interval

  Female anubis baboons with ample food and health can breed annually. However the interbirth interval ranges between 12 and 34 months, because female condition and food supply vary.

• Breeding season

  Mating can occur throughout the year.

• Average number of offspring

  1

• Average gestation period

  180 days

• Average weaning age

  420 days

• Average time to independence

  420 days

• Range age at sexual or reproductive maturity (female)

  7 to 8 years

• Range age at sexual or reproductive maturity (male)

  7 to 10 years

Most parental be­hav­ior 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. This dif­fer­ence has been re­ported in anu­bis ba­boons only up to the age of 8 weeks of in­fant life, but may be longer for some fe­males or in some troops. An­other dif­fer­ence seen in ma­ter­nal be­hav­ior in this species is that older moth­ers are known to spend more time in con­tact or close to their in­fants and are less likely to ter­mi­nate bouts of nurs­ing than are younger fe­males. First-time moth­ers are also likely to re­ject in­fants sooner than are ex­pe­ri­enced moth­ers. These dif­fer­ences may af­fect in­ter­birth in­ter­vals. (Alt­mann, 1980; Mel­nick and Pearl, 1987; Nicol­son, 1987; Smuts and Nicol­son, 1989)

There does not seem to be co­op­er­a­tive care of off­spring among fe­males in P. anu­bis, but it is not un­com­mon for fe­males other than the mother to groom an in­fant, some­times pro­vid­ing al­lo­ma­ter­nal care to the in­fant. 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, fe­males 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. (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. 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. (Mel­nick and Pearl, 1987; Stein, 1984; Whit­ten, 1987)

How­ever, it should be noted that the re­la­tion­ship be­tween adult males and these 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 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

The max­i­mum lifes­pan of a cap­tive hamadryas ba­boon is mea­sured at 37.5 years. A cap­tive chacma ba­boon is re­ported to have lived 45 years in cap­tiv­ity. Al­though the lifes­pan of P. anu­bis has not been re­ported, it is likely to be sim­i­lar to these two species, al­though some­what shorter than these in the wild. (Nowak, 1999)

• Average lifespan
  Sex: male
  Status: captivity

  25.2 years

  Max Planck Institute for Demographic Research

Be­hav­ior

Ba­boons are quadrupedal, mainly ter­res­trial pri­mates. They are highly so­cial an­i­mals, with a com­plex multi-male, multi-fe­male so­cial struc­ture. Mem­bers of a troop travel, for­age, and sleep to­gether. An av­er­age troop may be com­prised of 39 to 97 an­i­mals. The move­ments of a troop may be lim­ited by the avail­abil­ity of ap­pro­pri­ate sleep­ing lo­ca­tions. Be­cause the troop beds down in trees, or 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. (Mel­nick and Pearl, 1987; Nowak, 1999)

All males em­i­grate from their natal troops, with 85 per cent 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." Some males may em­i­grate into new groups in pairs. These male pairs may be half - or full- sib­lings from the same natal troop. Aside from such oc­ca­sional life-long af­fil­i­a­tions, males do not main­tain long-term bonds with their male kin, as is seen in hamadryas ba­boons. (Mel­nick and Pearl, 1987; Pusey and Packer, 1987)

An in­ter­est­ing phe­nom­e­non in P. anu­bis is the sec­ondary trans­fer of aged adult males from their troops. Be­cause the abil­ity of a male to com­pete for mates is re­lated to youth and vigor, or to long-term so­cial re­la­tion­ships with fe­males, trans­fer to a new troop in old age can only re­duce a male’s op­por­tu­ni­ties to mate. In ad­di­tion, trans­fer­ring to a new group ex­poses a male to a great num­ber of haz­ards, in­clud­ing in­creased risk of pre­da­tion, and dan­gers from ag­gres­sion while in­te­grat­ing into the male dom­i­nance hi­er­ar­chy of the new group. How­ever, it ap­pears that aged males who once had high dom­i­nance ranks are the sub­jects of con­stant ha­rass­ment by younger males, who seem to re­mem­ber the for­mer "great­ness" of such older males. It seems that males with larger num­bers of fe­male "friends" are more likely to stay in their troop in spite of har­rass­ment. Males with­out many fe­male friends are more likely to trans­fer to new troops, thereby avoid­ing the costs of such ha­rass­ment. (Sapol­sky, 1996)

Be­cause males do not main­tain life-long so­cial ties with their kin, it is fe­male kin­ship that forms the core and sta­bil­ity of P. anu­bis so­ci­ety. Be­cause fe­males of this species do not em­i­grate from their natal groups, fe­male kin have life-long as­so­ci­a­tions. Within a troop of anu­bis 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 ne­ices, but grand­moth­ers aid­ing their grand­daugh­ters. (Mel­nick and Pearl, 1987)

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)

Within so­cially sim­i­lar cer­co­p­ithecines, fe­males have been known to es­tab­lish re­la­tion­ships across ma­tri­lines. Fe­males may be­friend oth­ers who are of sim­i­lar rank. Also, low rank­ing fe­males may at­tempt to gain favor with higher rank­ing fe­males by pro­vid­ing groom­ing and other af­fil­i­ate be­hav­iors. An ally with higher rank may pro­vide a low rank­ing fe­male with pref­er­en­tial ac­cess to scarce food re­sources, or sup­port dur­ing some ag­gres­sive en­coun­ters. (Bent­ley-Con­dit and Smith, 1999; Mel­nick and Pearl, 1987; Smuts, 1987b)

Be­cause the dom­i­nance po­si­tion of ba­boons is so im­por­tant in their so­ci­ety, a great deal of in­ves­ti­ga­tion of po­ten­tial phys­i­o­log­i­cal causes of dom­i­nance has been con­ducted. Most in­ves­ti­gated have been lev­els of those hor­mones thought to be im­por­tant in ag­gres­sive be­hav­ior and stress re­sponse. Some in­ter­est­ing cor­re­la­tions be­tween en­docrine pro­files and be­hav­ioral pat­terns have emerged. (Sapol­sky and Ray, 1989; Vir­gin, Jr. and Sapol­sky, 1997; Sapol­sky and Ray, 1989; Vir­gin, Jr. and Sapol­sky, 1997)

In gen­eral, sub­or­di­nate males who ini­ti­ated fights with other males had higher testos­terone lev­els than males who did not ini­ti­ate fights. They also had lower base lev­els of glu­co­cor­ti­coids (hor­mones as­so­ci­ated with stress and stim­u­la­tion of the adrenal glands). When sub­or­di­nate males were in­volved fre­quently in con­sortships, they were more likely to move into the top half of the male dom­i­nance hi­er­ar­chy within 3 years than were males with­out fre­quent con­sortships. Like dom­i­nant males, they had re­duced basal glu­co­cor­ti­coid lev­els and a larger glu­co­cor­ti­coid re­sponse to stres­sors. (Sapol­sky and Ray, 1989; Vir­gin, Jr. and Sapol­sky, 1997)

Major be­hav­ioral traits that seemed to con­tribute to low­ered lev­els of glu­co­cor­ti­coid hor­mones were as­so­ci­ated with the so­cial "skill­ful­ness" of the an­i­mals. Males with low basal lev­els of glu­co­cor­ti­coids were bet­ter able to dis­tin­guish be­tween neu­tral and threat­en­ing in­ter­ac­tions with their ri­vals. They also were more likely to ini­ti­ate ag­gres­sion against ri­vals in threat­en­ing in­ter­ac­tions than were males with higher basal glu­co­cor­ti­coid lev­els. The males with lower glu­co­cor­ti­coid lev­els showed the great­est skill in de­ter­min­ing whether they had won or lost an ag­gres­sive en­counter, and also showed the great­est in­ci­dence of "dis­place­ment ag­gres­sion" (ag­gres­sion at some­thing other than the rival or sit­u­a­tion that was re­ally up­set­ting them). (Sapol­sky and Ray, 1989; Vir­gin, Jr. and Sapol­sky, 1997)

Al­though it is not cur­rently known whether the glu­co­cor­ti­coid lev­els of in­di­vid­u­als lead to the be­hav­iors, or visa versa, clearly, there are mea­sur­able dif­fer­ences be­tween in­di­vid­u­als which may allow pre­dic­tion of their fu­ture re­pro­duc­tive suc­cess. Fur­ther re­search in this area promises to help us to bet­ter un­der­stand the ge­netic and phys­i­o­log­i­cal un­der­pin­nings of so­cial be­hav­ior and suc­cess in this species. (Sapol­sky and Ray, 1989; Vir­gin, Jr. and Sapol­sky, 1997)

• Key Behaviors
• terricolous
• diurnal
• motile
• nomadic
• sedentary
• territorial
• social
• dominance hierarchies

• Range territory size

  0.39 to 1.968 km^2

Home Range

Home ranges be­tween 390 and 1,968 ha have been re­ported. The daily range of a troop av­er­ages 5,800 m. (Mel­nick and Pearl, 1987)

Com­mu­ni­ca­tion and Per­cep­tion

As in all highly so­cial species, com­mu­ni­ca­tion is var­ied and com­plex. Anu­bis ba­boons uti­lize vi­sual sig­nals and ges­tures, vo­cal­iza­tions, and tac­tile com­mu­ni­ca­tion. (Pri­mate Info Net, 2000)

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. 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 re­treat­ing from high-ten­sion sit­u­a­tions use rapid glances to break ten­sion. Adult males who are guard­ing mates some­times sit with their erect penis in plain view. This pe­nile dis­play com­mu­ni­cates the male’s pres­ence to other males. (Pri­mate Info Net, 2000)

Teeth chat­ter­ing and lips­mack­ing, al­though not tech­ni­cally vo­cal­iza­tions, are au­di­tory cues of re­as­sur­ance, often per­formed by a dom­i­nant an­i­mal when an­other is pre­sent­ing to it. (Pri­mate Info Net, 2000)

Vo­cal­iza­tions made by anu­bis 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. Adult male anu­bis ba­boons make grunt­ing vo­cal­iza­tions as a threat, and are known to "roar" dur­ing fights. A grat­ing roar, which is a deep, res­onat­ing call, is given by a dom­i­nant male after a fight, and is some­times made by adult males when there is a night-time dis­tur­bance. Screech­ing is com­mon dur­ing ag­gres­sive en­coun­ters, and can be made by any age or sex class. Subadult and adult olive 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 anu­bis ba­boons ex­cept in­fants when they wish to sig­nal re­as­sur­ance to an­other an­i­mal. (Pri­mate Info Net, 2000)

Ju­ve­niles and in­fants pro­duce some vo­cal­iza­tions unique to their age class. These in­clude click­ing, which is a chirp-like noise which is anal­o­gous to yakking of adults. They also pro­duce an ick-ooer sound which com­mu­ni­cates a low level of dis­tress. (Pri­mate Info Net, 2000)

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, 2000)

Chem­i­cal com­mu­ni­ca­tion has also been re­ported for this species. 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. (Hrdy and Whit­ten, 1987)

• Communication Channels
• visual
• tactile
• acoustic
• chemical

• Perception Channels
• visual
• tactile
• acoustic
• chemical

Food Habits

Anu­bis ba­boons are known to eat a wide va­ri­ety of foods. They con­sume fruits, tree gums, in­sects, eggs, seeds, flow­ers, grass, rhi­zomes, corms, roots, tu­bers and small ver­te­brates. (Mel­nick and Pearl, 1987; Pri­mate Info Net, 2000; Strum, 1991)

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. (Mel­nick and Pearl, 1987; Oates, 1987)

• Primary Diet
• omnivore

• Animal Foods
• birds
• mammals
• reptiles
• eggs
• carrion
• insects
• terrestrial non-insect arthropods

• Plant Foods
• leaves
• roots and tubers
• seeds, grains, and nuts
• fruit

Pre­da­tion

Two preda­tor species are known for anu­bis ba­boons. Leop­ards and chim­panzees have been known to kill these an­i­mals. Anu­bis ba­boons have been re­ported to mob leop­ards, often with adult males lead­ing the at­tack. In the Gombe pre­serve in Tan­za­nia, an es­ti­mated one per­cent of the pop­u­la­tion falls vic­tim to preda­tors an­nu­ally. Of these, about 3/4 are in­fants, and 1/4 are ju­ve­niles. (Ch­eney and Wrang­ham, 1987; Mel­nick and Pearl, 1987; Nowak, 1999)

• Known Predators

  • chimpanzees (Pan troglodytes)
  • leopards (Panthera pardus)

Ecosys­tem Roles

Ba­boons likely play a role in aer­at­ing the soil through the dig­ging of corms, roots, and tu­bers. They also are likely to dis­perse seeds of the fruits and grains that they eat. Ba­boons pro­vide food for their preda­tors, and also exert some af­fect on pop­u­la­tions of small an­i­mals on which they feed. (Mel­nick and Pearl, 1987; Pri­mate Info Net, 2000)

• Ecosystem Impact
• disperses seeds
• soil aeration

Eco­nomic Im­por­tance for Hu­mans: Pos­i­tive

Anu­bis ba­boons are used in med­ical and be­hav­ioral re­search. They are so­cially ac­tive an­i­mals which pro­vide en­ter­tain­ment for zoo vis­i­tors and eco­tourists. (Nowak, 1999)

• Positive Impacts
• ecotourism
• research and education

Eco­nomic Im­por­tance for Hu­mans: Neg­a­tive

Ba­boons are large an­i­mals, and not par­tic­u­larly timid of hu­mans. They are known to raid crops, and can at­tack and in­jure hu­mans if pro­voked. (Mel­nick and Pearl, 1987; Nowak, 1999; Strum, 1991)

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

Con­ser­va­tion Sta­tus

Anu­bis ba­boons are not con­sid­ered threat­ened or en­dan­gered. The IUCN Redlist rates them "Lower Risk, Least Con­cern." Like most pri­mates, they are in­cluded in Ap­pen­dix II of the CITES, so in­ter­na­tional trade in the an­i­mals or their parts re­quires gov­ern­ment ap­proval.

• IUCN Red List

  Least Concern
  More information

• IUCN Red List

  Least Concern
  More information

• CITES

  Appendix II

Other Com­ments

Hy­bridiza­tion be­tween Papio hamadryas and P. anu­bis oc­curs along the Awash river val­ley in Ethiopia. The area of hy­bridiza­tion ap­pears to be sta­ble, with­out no­tice­able in­tro­gres­sion of P. hamadryas phe­no­types into anu­bis ba­boon pop­u­la­tions or of P. anu­bis phe­no­types into hamadryas ba­boon pop­u­la­tions. The rea­sons for this sta­bil­ity are prob­a­bly very com­plex. How­ever, it is worth dis­cussing two con­trib­u­tors to this sta­bil­ity in this forum. (Mel­nick and Pearl, 1987; Nowak, 1999; Phillips-Con­roy, et al., 1992)

In hamadryas ba­boons, the basic so­cial unit, or OMU, is main­tained as a co­he­sive en­tity through the ac­tiv­ity of the adult male leader of the OMU. He herds fe­males and ju­ve­niles, reg­u­lates their in­ter­ac­tions, and pre­vents them from stray­ing. Al­though anu­bis ba­boon males pos­sess the same basic be­hav­iors that would allow the males of this species to form one-male-units, there are sig­nif­i­cant dif­fer­ences in ex­pres­sion be­tween the two species which make it im­pos­si­ble for male anu­bis ba­boons mi­grat­ing into hamadryas ter­ri­tory to suc­cess­fully main­tain a harem of fe­males. (Kum­mer, 1968; Phillips-Con­roy, et al., 1992)

For ex­am­ple, al­though male anu­bis ba­boons ag­gres­sively herd fe­males and ex­clude rival males, they tend to do so only when the fe­males are in es­trus. This would pre­vent a male anu­bis ba­boon from main­tain­ing a co­he­sive OMU in the hamadryas fash­ion. Also, al­though they form close so­cial ties with fe­males, they do not ex­hibit the "re­spect" of the re­la­tion­ship be­tween other males and their fe­males which is typ­i­cal of hamadryas ba­boons. This may be re­lated to dif­fer­ences in the kin as­so­ci­a­tions of hamadryas and anu­bis ba­boons. Cor­re­lated with this, an anu­bis male try­ing to "steal" a sex­u­ally at­trac­tive fe­male from a male hamadryas, would incur not just the wrath of that male, but likely the wrath of that male’s kin within the clan. (Kum­mer, 1968; Mel­nick and Pearl, 1987; Nowak, 1999; Phillips-Con­roy, et al., 1992)

Hy­brid males are known to show be­hav­ior in­ter­me­di­ate be­tween the two parental species. Anu­bis-like hy­brids form last­ing so­cial bonds with ane­strous fe­males, and as­sume a con­sort-like sta­tus when the fe­males are in es­trus. How­ever, they are un­able to herd them ef­fi­ciently be­cause they do not ex­press this be­hav­ior when the fe­males are ane­strous. The more hamadryas-like hy­brids are ca­pa­ble of form­ing OMUS. (Phillips-Con­roy, et al., 1992)

In­ter­est­ingly, hamadryas males have been known to ef­fec­tively in­te­grate into anu­bis ba­boon troops. Al­though fe­males mate with them, these males may still be at a re­pro­duc­tive dis­ad­van­tage rel­a­tive to anu­bis males. Be­cause the mat­ing sys­tem of the hamadryas ba­boon char­ac­ter­is­ti­cally in­volves only one male, there has been lit­tle se­lec­tion for sperm com­pe­ti­tion in this species. Hamadryas males have both rel­a­tively and ab­solutely smaller tes­ti­cles than do anu­bis males. This likely re­sults in lower pro­duc­tion of sperm. Since fe­male anu­bis ba­boons may mate with a num­ber of males dur­ing their es­trus cycle, lower sperm pro­duc­tion by hamadryas males may lessen their chances for sir­ing off­spring. This may con­tribute to the sta­bil­ity of the hy­brid zone. (Jolly and Phillips-Con­roy, 2003; Mel­nick and Pearl, 1987; Phillips-Con­roy, et al., 1992)

Anu­bis ba­boons are also known to hy­bridize freely in the wild with yel­low ba­boons,. In the Am­boseli Na­tional Park in Kenya, the amount of re­ported hy­bridiza­tion be­tween these two species has in­creased over time. Re­searchers think that the in­creas­ing im­mi­gra­tion of anu­bis males into yel­low ba­boon troops is re­spon­si­ble for the in­crease noted in hy­brid char­ac­ters. Be­cause the slopes of Mount Kil­a­man­jaro are under in­creas­ing agri­cul­tural pres­sure, it is likely that anu­bis males have no al­ter­na­tive areas into which to em­i­grate. (Al­berts and Alt­mann, 2001; Jolly, 1993)

The only dif­fer­ences noted in be­hav­ior of hy­brid an­i­mals is that males with anu­bis-like fea­tures (e.g. coarser hair, longer manes, darker col­oration, broader chests, and more sharply "bro­ken" tails) tend to em­i­grate from their natal group as ju­ve­niles or subadults, rather than as full adults. This be­hav­ior has been seen oc­ca­sion­ally in the anu­bis ba­boons of the Gombe pre­serve in Tan­za­nia, but is not known in yel­low ba­boons. (Al­berts and Alt­mann, 2001; Pusey and Packer, 1987)

The hy­bridiza­tion be­tween anu­bis and yel­low ba­boons seems to have a long his­tory. In­ter­est­ing, the Ibean form of yel­low ba­boon, which has coarser hair than the typ­i­cal yel­low ba­boon, a more pro­nounced mane, and other some­what "anu­bis-like" fea­tures, is thought by some re­searchers to be ev­i­dence of the his­tor­i­cal in­flux of anu­bis genes into yel­low ba­boon pop­u­la­tions. (Al­berts and Alt­mann, 2001; Jolly, 1993)

Con­trib­u­tors

Nancy Shef­ferly (au­thor), An­i­mal Di­ver­sity Web, George Ham­mond (ed­i­tor), An­i­mal Di­ver­sity Web.

Ref­er­ences

Al­berts, S., J. Alt­mann. 2001. Im­mi­gra­tion and hy­bridiza­tion pat­terns of yel­low and anu­bis ba­boons in and around Am­boseli, Kenya. Amer­i­can Jour­nal of Pri­ma­tol­ogy, `53: 139-154.

Alt­mann, J. 1980. Ba­boon Moth­ers and In­fants. Chicago: The Uni­ver­sity of Chicago Press.

Bent­ley-Con­dit, V., E. Smith. 1999. Fe­male dom­i­nance and fe­male so­cial re­la­tion­ships among yel­low ba­boons (Papio hamadryas cyno­cephalus). Amer­i­can Jour­nal of Pri­ma­tol­ogy, 47: 321-334.

Bercov­itch, F. 1987. Fe­male weight and re­pro­duc­tive con­di­tion in a pop­u­la­tion of olive ba­boons (Papio anu­bis). Amer­i­can Jour­nal of Pri­ma­tol­ogy, 12: 189-195.

Ch­eney, D., R. Wrang­ham. 1987. Pre­da­tion. Pp. 227-239 in B Smuts, D Ch­eney, R Sey­farth, R Wrang­hams, T Struh­saker, eds. Pri­mate So­ci­eties. Chicago: The Uni­ver­sity of chicago Press.

Groves, C. 2001. Pri­mate Tax­on­omy. Wash­ing­ton, D.C.: Smith­son­ian In­si­tu­tion Press.

Hamil­ton III, W., J. Bul­ger. 1992. Fac­ul­ta­tive ex­pre­sion of be­hav­ioral dif­fer­ences be­tween one-male and mul­ti­male sa­vanna ba­boon groups. Amer­i­can Jour­nal of Pri­ma­tol­ogy, 28: 61-71.

Hrdy, S., P. Whit­ten. 1987. Pat­tern­ing of sex­ual ac­tiv­ity. Pp. 370-384 in B Smuts, D Ch­eney, R Sey­farth, R Wrang­ham, T Struh­saker, eds. Pri­mate So­cieities. Chicago: The Uni­ver­sity of Chicago PRess.

Jolly, C. 1993. Species, sub­species, and ba­boon sys­tem­at­ics. Pp. 67-107 in W Kim­bel, L Mar­tin, eds. Species, Species Con­cepts, and Pri­mate Evo­lu­tion. New York: Plenum Pub­lish­ing.

Jolly, C., J. Phillips-Con­roy. 2003. Tes­tic­u­lar size, mat­ing sys­tem, and mat­u­ra­tion sched­ules in wild anu­bis and hamadryas ba­boons. In­ter­na­tional Jour­nal of Pri­ma­tol­ogy, 24/1: 125-142.

Kum­mer, H. 1968. So­cial Or­gan­i­sa­tion of Hamdryas Ba­boons. A Field Study. Basel and Chicago: Karger, and Uni­ver­sity Press.

Mel­nick, D., M. Pearl. 1987. Cer­co­p­ithecines in mul­ti­male groups: Ge­netic di­ver­sity and pop­u­la­tion struc­ture. Pp. 121-134 in B Smuts, D Ch­eney, R Sey­farth, R Wrang­ham, T Struh­saker, eds. Pri­mate So­ci­eties. Chicago: The Uni­ver­sity of Chicago Press.

Napier, J., P. Napier. 1985. The nat­ural his­tory of the pri­mates. Cam­bridge, Mass­a­chu­setts: The MIT Press.

Nicol­son, N. 1987. In­fants, moth­ers, and other fe­males. Pp. 330-342 in B Smuts, D Ch­eney, R Sey­farth, R Wrang­ham, T Struh­saker, eds. Pri­mate So­ci­eties. Chicago: The Uni­ver­sity of Chicago Press.

Nowak, R. 1999. Walker's Mam­mals of the World, Sixth Edi­tion. Bal­ti­more: The Johns Hop­kins Uni­ver­sity Press.

Oates, J. 1987. Food dis­tri­b­u­tion and for­ag­ing be­hav­ior. Pp. 197-209 in B Smuts, D Ch­eney, R Sey­farth, R Wrang­ham, T Struh­saker, eds. Pri­mat So­ci­eties. Chicago: The Uni­ver­sity of Chicago Press.

Phillips-Con­roy, J., C. Jolly, P. Ny­s­trom, H. Hem­ma­lin. 1992. Mi­gra­tion of male hamadryas ba­boons into anu­bis groups in the Awash Na­tional Park, Ethiopia. In­ter­na­tional Jour­nal of Pri­ma­tol­ogy, 12/4: 455-475.

Pri­mate Info Net, 2000. "Pri­mate Info Net" (On-line). Olive Ba­boon (Papio anu­bis). Ac­cessed July 14, 2003 at http://​www.​primate.​wisc.​edu/​pin/​factsheets/​papio_​anubis.​html.

Pusey, A., C. Packer. 1987. Dis­per­sal and philopa­try. Pp. 250-266 in B Smuts, D Ch­eney, R Sey­farth, R Wrang­ham, T Struh­saker, eds. Pri­mate So­ci­eties. Chicago: The Uni­ver­sity of Chicago Press.

Rhine, R., R. Tilson. 1987. Re­ac­tions to fear as a prox­i­mate fac­tor in the so­ciospa­tial or­ga­ni­za­tion of ba­boon pro­gres­sions. Amer­i­can Jour­nal of Pri­ma­tol­ogy, 13: 119-128.

Rogers, J. 2000. Mol­e­c­u­lar ge­netic vari­a­tion and pop­u­la­tion struc­ture in Papio ba­boons. Pp. 57-76 in P White­head, C Jolly, eds. Old World Mon­keys. Cam­bridge, UK: Cam­bridge Uni­ver­sity Press.

Sapol­sky, R., J. Ray. 1989. Styles of dom­i­nance and their en­docrine cor­re­lates among wild olive ba­boons (Papio anu­bis). Amer­i­can Jour­nal of Pri­ma­tol­ogy, 18: 1-13.

Sapol­sky, R. 1996. Why should an aged male ba­boon ever trans­fer troops?. Amer­i­can Jour­nal of Pri­ma­tol­ogy, 39. Ac­cessed (Date Un­known) at 149-157.

Smuts, B. 1987. Gen­der, ag­gres­sion, and in­flu­ence. Pp. 400-412 in B Smuts, D Ch­eney, R Sey­farth, R Wrang­ham, T Struh­saker, eds. Pri­mate So­ci­eties. Chicago: The Uni­ver­sity of Chicago Press.

Smuts, B. 1987. Sex­ual com­pe­ti­tion and mate choice. Pp. 385-399 in B Smuts, D Ch­eney, R Sey­farth, R Wrang­ham, T Struh­saker, eds. Pri­mate So­ci­eties. Chicago: The Uni­ver­sity of Chicago Press.

Smuts, B., N. Nicol­son. 1989. Re­pro­duc­tion in wild fe­male olive ba­boons. Amer­i­can Jour­nal of Pri­ma­tol­ogy, 19: 229-246.

Stein, D. 1984. The So­cio­bi­ol­ogy of Adult Male and In­fant Ba­boons. Nor­wood, NJ: Ablex Pub­lish­ing.

Strum, S. 1991. Weight and age in wild olive ba­boons. Amer­i­can Jour­nal of Pri­ma­tol­ogy, 25: 219-237.

Vir­gin, Jr., C., R. Sapol­sky. 1997. Styles of male so­cial be­hav­ior and their en­docrine cor­re­lates among low-rank­ing male ba­boons. Amer­i­can Jour­nal of Pri­ma­tol­ogy, 42: 25-39.

Wal­ters, J. 1987. Tran­si­tion to Adult­hood. Pp. 358-369 in B Smuts, D Ch­eney, R Sey­farth, R Wrang­ham, T Struh­saker, eds. Pri­mate So­ci­eties. Chicago: The Uni­ver­sity of Chicago Press.

Wal­ters, R., R. Sey­farth. 1987. Con­flict and co­op­er­a­tion. Pp. 306-317 in B Smuts, D Ch­eney, R Sey­farth, R Wrang­ham, T Struh­saker, eds. Pri­mate So­ci­eties. Chicago: The Uni­ver­sity of Chicago Press.

Whit­ten, P. 1987. In­fants and adult males. Pp. 343-357 in B Smuts, D Ch­eney, R Sey­farth, R Wrang­ham, T Struh­saker, eds. Pri­mate So­ci­eties. Chicago: The Uni­ver­sity of Chicago Press.

Williams-Blangero, S., J. Van­den­berg, J. Blangero, L. Konigs­berg, B. Dyke. 1990. Ge­netic dif­fer­en­ti­a­tion be­tween ba­boon sub­species: Rel­e­vance for bio­med­ical re­search. Amer­i­can Jour­nal of Pri­ma­tol­ogy, 20: 67-81.