Animal Diversity Web

Ge­o­graphic Range

White-faced sakis (Pithe­cia pithe­cia) are lo­cated in Brazil, and re­mote parts of Venezuela. Their range also en­com­passes most of French Guiana, Guyana and Suri­name. They live along the Cuyuni river basin, east of the Ca­roni River, and south of the Orinoco River. (Veiga and Marsh, 2008)

• Biogeographic Regions
• neotropical
  • native

Habi­tat

White-faced sakis are ar­bo­real and live in both up­land and low­land rain­forests. Al­though they can in­habit very wet and very dry forests, they pre­fer areas with an abun­dance of fruit trees and wa­ter­ing holes. This species is most com­mon at canopy heights of 15 to 25 m. They will also spend time for­ag­ing on the ground and at low lev­els in the un­der­story fo­liage (3 to 15 m). Overnight sleep­ing areas typ­i­cally are larger trees in the canopy with a wealth of fo­liage for cover. (Anzelc, 2009; Cun­ning­ham and Jan­son, 2007)

• Habitat Regions
• tropical
• terrestrial

• Terrestrial Biomes
• rainforest

Phys­i­cal De­scrip­tion

White-faced sakis ex­hibit sex­ual di­mor­phism, with larger males, and sex­ual dichro­ma­tism. Males have a black coat with white fur that sur­rounds their face. Fe­male sakis have a shorter, brown­ish grey coat with two ver­ti­cal lines from their eyes to their nose. Fe­males may also have or­ange brown col­ored fur that emerges around the chest area and con­tin­ues down to their ab­domen. At birth males and adult fe­males are very sim­i­lar in ap­pear­ance. A grad­ual color change over 3.5 to 4 years oc­curs, in which male sakis be­come all black with bright white faces. Sakis have long bushy tails, which are used for bal­ance while jump­ing from tree to tree. The tails are not used for grasp­ing ob­jects or branches. Av­er­age adult mass is 1.8 kg; how­ever, a slight sex­ual di­mor­phism sep­a­rates males (2.38 kg) from fe­males (1.76 kg). (Anzelc, 2009; Flea­gle and Mel­drum, 1988; Nor­conk, 2006)

• Other Physical Features
• endothermic
• bilateral symmetry

• Sexual Dimorphism
• male larger
• sexes colored or patterned differently
• male more colorful

• Average mass

  1.871 kg

  4.12 lb

Re­pro­duc­tion

Sakis are known to be monog­a­mous in cap­tiv­ity (zoo en­vi­ron­ments) al­though Wa­ters (1995) in­di­cates there have been ex­cep­tions in the wild. Anzelc (2009) sug­gests that monogamy in the wild is less com­mon than ex­pected, and is less com­mon when groups are larger than 2 to 3 in­di­vid­u­als. Groups of 4 to 6 are not un­com­mon, and can in­clude more than one adult breed­ing male or fe­male. This sug­gests polyg­a­mous or polyan­drous mat­ing sys­tem, de­pend­ing on the break­down of adults in the group. (Anzelc, 2009; Wa­ters, 1995)

• Mating System
• monogamous
• polyandrous
• polygynous

Males and fe­males live in small groups. De­spite prac­tic­ing monogamy in zoos, a study of wild sakis in Venezuela found that some sakis were not monog­a­mous. In wild groups, males will make calls to the fe­males dur­ing mat­ing sea­son in­stead of as an alarm call. Males reach sex­ual ma­tu­rity in ap­prox­i­mately 32 months. Fe­males are about the same age, but can take sev­eral months more. It isn't until the fe­males' ovar­ian cycle is reg­u­lar that they are de­ter­mined sex­u­ally ma­ture. Ges­ta­tion pe­ri­ods for sakis av­er­age 146 days, and fe­males bear 1 off­spring at a time. Saki sib­lings from the pre­vi­ous year or 2 may help care for a new­born saki. (Nor­conk, 2006)

• Key Reproductive Features
• iteroparous
• seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual
• viviparous

• Breeding interval

  Sakis breed once per year.

• Breeding season

  Sakis breed in the spring.

• Average number of offspring

  1

• Average gestation period

  146 days

• Average age at sexual or reproductive maturity (male)

  32 months

Fe­males sakis are the pre­dom­i­nant care­tak­ers. In­fants stay at­tached to their mother's thigh from birth to 1 month. From age one to four months, the young shift to a dor­sal po­si­tion where they can achieve greater mo­bil­ity. The moth­ers carry their in­fants for the first 3 months. After the in­fant is around the age of 5 months, the mother will stop car­ry­ing it. They feed, pro­tect, and nur­ture young until they are ready to be on their own. How­ever, in­fants ob­serve one birthing event prior to leav­ing their fam­ily group. (Nor­conk, 2006; Wa­ters, 1995)

• Parental Investment
• female parental care
• 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

Lifes­pan/Longevity

In the wild, white-faced sakis have been known to live about 15 years. One wild-caught saki in cap­tiv­ity lived to the age of 36, spend­ing over 28 of those years in cap­tiv­ity. (de Ma­g­a­l­haes and Costa, 2009)

• Range lifespan
  Status: captivity

  36 (high) years

• Average lifespan
  Status: wild

  15 years

Be­hav­ior

Sakis are so­cial but live in small groups of just 2 to 4 in­di­vid­u­als. The groups travel to­gether daily, and can eas­ily move 1 to 2 km per day. Most move­ment oc­curs in the early morn­ing and early hours of the af­ter­noon. They spend about 9 hours on the move. These ac­tiv­ity bouts are rel­a­tively shorter than re­lated mon­keys, who may be ac­tive 10 to 12 hours per day. Sakis are adept leapers aid­ing in preda­tor avoid­ance. Male and fe­male sakis ex­hibit groom­ing and mat­ing be­hav­iors, most com­mon be­tween moth­ers and in­fants. Male and fe­male sakis teach each other how to raise the young. In cap­tiv­ity sakis have been known to carry group mem­ber's in­fant. (Anzelc, 2009; Walker, 2005; Wa­ters, 1995)

Fe­males in cap­tiv­ity start to re­pro­duce much ear­lier in age than they would in the wild, which leads to ear­lier mor­tal­ity. After reach­ing at least 37 months, the sur­vival rate of the in­di­vid­ual greatly in­creases. The longer the fe­male waits to re­pro­duce, the longer she will live. One ex­am­ple of late birthing was ob­served in an 18-year-old saki who gave birth in a zoo. This saki lived in the wild in its na­tive habi­tat until she was cap­tured late in life al­ter­ing her be­hav­ior from those reared in cap­tiv­ity. (Wa­ters, 1995)

• Key Behaviors
• arboreal
• motile
• sedentary
• territorial
• social

• Range territory size

  1 to 15.2 km^2

Home Range

Groups of sakis in Suri­name have been known to use a rel­a­tively small home range of 10 hectares. Re­lo­cated groups uti­lize much larger home ranges, and re­ports of 68 to 152 ha were typ­i­cal. These sakis will mark and de­fend their ter­ri­tory by a se­ries of ac­tiv­i­ties. Anzelc (2009) sum­ma­rizes them as "scent gland (ster­nal/gular/anogen­i­tal) rub­bing, urine-wash­ing, and ter­ri­to­r­ial calls ....​and ag­o­nis­tic in­ter­ac­tions, using grunts, trills, branch and body shakes, pi­lo­erec­tion, and fast pur­suits to threaten and dis­place ex­tra-group mem­bers." (Anzelc, 2009)

Com­mu­ni­ca­tion and Per­cep­tion

Sakis live in small groups rang­ing from 2 to 4 in­di­vid­u­als; how­ever larger groups of 6 or more have been re­ported and may in­clude more than one adult breed­ing male or fe­male. To es­tab­lish ter­ri­tory they have loud vocal calls usu­ally per­formed in duets of monog­a­mous males and fe­males. These duets strength­ens their courtship bond. They also so­cial­ize by groom­ing on one an­other. White-faced sakis will scent-mark an area. Males rub their chests on trees. They usu­ally choose trees with ed­i­ble fruit to ex­cite fe­males and to try to stim­u­late courtship be­hav­ior dur­ing breed­ing sea­son. (Anzelc, 2009; Lehman, et al., 2001; Setz and Gas­par, 1997)

• Communication Channels
• visual
• tactile
• acoustic
• chemical

• Other Communication Modes
• duets
• pheromones
• scent marks
• vibrations

• Perception Channels
• visual
• tactile
• acoustic
• vibrations
• chemical

Food Habits

Sakis eat the seeds of fruit­ing bod­ies. They spend 95 to 99% of total con­sump­tion time eat­ing and break­ing open the seeds. Year-round, they pre­fer to eat seeds 38 to 88% of the time. Leaves are also an im­por­tant source of food. They eat the young leaves of plants dur­ing the dry sea­son when fruits are not plen­ti­ful. Given this diet, their in­take of fats are ex­tremely high, but their in­take of pro­teins are low. On oc­ca­sion, they have been known to con­sume in­sects and flow­ers when fruit is scarce. (Anzelc, 2009; Nor­conk and Con­klin-Brit­tain, 2004)

• Primary Diet
• herbivore
  • folivore
  • frugivore
  • granivore

• Animal Foods
• insects

• Plant Foods
• leaves
• seeds, grains, and nuts
• fruit
• flowers

Pre­da­tion

When a ter­res­trial preda­tor, such as red-tailed boas, are near sakis will first make an alarm call. Then they will group to­gether and mob the preda­tor in hopes of dri­ving it away. Other ter­res­trial preda­tors in­clude a weasel called tayras, jaguars, green ana­con­das, and ocelots. Their biggest threats are avian preda­tors. Be­cause of their size, sakis are easy prey to the harpy eagle, which are known to at­tack large pri­mates. A study re­ported more alarm calls when there is an avian threat, such as an eagle or vul­ture. When a bird of prey is spot­ted sakis make the alarm call, which is echoed by group mem­ber, and then they stay com­pletely mo­tion­less. After time has elapsed, sakis might slip out un­de­tected, head­ing for low­est parts of the canopy. They try to re­main as con­cealed as pos­si­ble in the canopy. (Nor­conk and Glea­son, 2002)

• Anti-predator Adaptations
• aposematic

• Known Predators

  • tayra (Eira barbara)
  • jaguars (Panthera onca)
  • green anacondas (Eunectes murinus)
  • ocelots (Leopardus pardalis)
  • red-tailed boa (Boa constrictor)
  • vultures and harpy eagles (Harpia harpyja)

Ecosys­tem Roles

Saki have par­a­sites typ­i­cal to that of new world mon­keys and non-hu­man pri­mates. For ex­am­ple a com­mon par­a­sites are round­worms (Ptery­go­der­matites nyc­ticebi). Heart­worms (Diro­fi­laria im­mi­tis) are pre­sent in this species, too. They can also get dis­eases such as di­a­betes and the Ma­yaro virus (which is found in mam­mals that live in trees). (Gam­ble, et al., 1998; Thoisy, et al., 2003)

• Ecosystem Impact
• disperses seeds

Eco­nomic Im­por­tance for Hu­mans: Pos­i­tive

White-faced sakis are charais­matic or­gan­isms that at­tract high in­ter­est in zoos, how­ever they are re­cently being ex­ploited for their charisma. There is a mar­ket for these mon­keys as pets, which is detri­men­tal to the sakis. They are hunted as a source of food by lo­cals. This hurts the pop­u­la­tion of sakis, be­cause they don't re­pro­duce quickly enough to re­place the in­di­vid­u­als killed and cap­tured. ("White-Faced Saki Mon­key", 2012)

• Positive Impacts
• pet trade
• food
• body parts are source of valuable material

Eco­nomic Im­por­tance for Hu­mans: Neg­a­tive

Sakis may carry dis­eases which can be trans­ferred to hu­mans in­clud­ing the he­pati­tis virus and the nat­u­rally oc­cur­ring her­pes vir­sus (HSV-1). How­ever, they are not a major dis­ease trans­mit­ter. (Schren­zel, et al., 2003)

• Negative Impacts
• injures humans
  • carries human disease
• causes or carries domestic animal disease

Con­ser­va­tion Sta­tus

This species is not cur­rently listed by IUCN and is of lit­tle con­cern for con­ser­va­tion man­agers. How­ever, due to habi­tat de­struc­tion and the pet trade, this sta­tus could change. It is listed in Ap­pen­dix II of CITES, in­di­cat­ing that the species could be­come threat­ened if trade or im­port and/or ex­port is not reg­u­lated. (Veiga and Marsh, 2008)

• IUCN Red List

  Least Concern

• US Federal List

  No special status

• CITES

  Appendix II

• State of Michigan List

  No special status

Con­trib­u­tors

Nicole Gru­bich (au­thor), Rad­ford Uni­ver­sity, Karen Pow­ers (ed­i­tor), Rad­ford Uni­ver­sity, Kier­sten Newtoff (ed­i­tor), Rad­ford Uni­ver­sity, Melissa Whistle­man (ed­i­tor), Rad­ford Uni­ver­sity.

Ref­er­ences

2012. "White-Faced Saki Mon­key" (On-line). Ore­gon Zoo. Ac­cessed April 09, 2012 at http://​www.​oregonzoo.​org/​discover/​animals/​white-faced-saki-monkey.

Anzelc, A. 2009. The For­ag­ing and Travel Pat­terns of White-Faced Sakis in Browns­berg Na­ture Park, Suri­name: Pre­lim­i­nary Ev­i­dence for Goal-Di­rected For­ag­ing Be­hav­ior. Kent, Ohio: Kent State Uni­ver­sity, Mas­ter's the­sis, 194 oo.. Ac­cessed April 24, 2012 at http://​www.​personal.​kent.​edu/​~mnor­conk/pdfs/Anzelc-thesis-7-20-09b.​pdf.

Cun­ning­ham, E., C. Jan­son. 2007. In­te­grat­ing in­for­ma­tion about lo­ca­tion and value of re­sources by white-faced saki mon­keys (Pithe­cia pithe­cia). An­i­mal Cog­ni­tion, 10/3: 293-304.

Flea­gle, J., D. Mel­drum. 1988. Lo­co­mo­tor be­hav­ior and skele­tal mor­phol­ogy of two sym­patric Pitheci­ine mon­keys, Pithe­cia pithe­cia and Chi­ropotes sa­tanas. Amer­i­can Jour­nal of Pri­ma­tol­ogy, 16/3: 227-249.

Gam­ble, K., J. Fried, G. Rubin. 1998. Pre­sump­tive diro­fi­lar­i­a­sis in a pale-headed saki mon­key (Pithe­cia pithe­cia). Jour­nal of Zoo and Wildlife Med­i­cine, 29/1: 50-54.

Lehman, S., W. Prince, M. Mayor. 2001. Vari­a­tions in group size in white-faced sakis (Pithe­cia pithe­cia): Ev­i­dence for monogamy or sea­sonal con­gre­ga­tions. Neotrop­i­cal Pri­mates, 9/3: 96-100.

Lloyd, M., J. Susa, J. Pelto, A. Sav­age. 1995. Ges­ta­tional di­a­betes mel­li­tus in a white-faced saki (Pithe­cia pithe­cia). Jour­nal of Zoo and Wildlife Med­i­cine, 26/1: 76-81.

Nor­conk, M. 2006. Long-term study of group dy­nam­ics and fe­male re­pro­duc­tion in Venezue­lan Pithe­cia pithe­cia. In­ter­na­tional Jour­nal of Pri­ma­tol­ogy, 27/3: 653-674.

Nor­conk, M., A. Rosen­berger, P. Gar­ber. 1996. Adap­tive Ra­di­a­tions of Neotrop­i­cal Pri­mates. New York: Plenum Press.

Nor­conk, M., N. Con­klin-Brit­tain. 2004. Vari­a­tion on fru­givory: The diet of Venezue­lan white-faced Sakis. In­ter­na­tion Jour­nal of Pri­ma­tol­ogy, 25/1: 1-26.

Nor­conk, M., T. Glea­son. 2002. Pre­da­tion risk and an­tipreda­tor adap­ta­tions in white-faced sakis, Pithe­cia pithe­cia. Pp. 169-183 in L Miller, ed. Eat or be eaten: preda­tor sen­si­tive for­ag­ing among pri­mates. Cam­bridge, United King­dom: Press Syn­di­cate of the Uni­ver­sity of Cam­bridge.

Richard-Hansen, C., C. Fournier-Cham­bril­lon. 2001. Abun­dance, use of space, and ac­tiv­ity pat­terns of white-faced sakis (Pithe­cia pithe­cia) in French Guiana. Amer­i­can Jour­nal of Pri­ma­tol­ogy, 55/4: 203-221.

Schren­zel, M., K. Os­born, A. Shima, R. Klieforth, G. Maalouf. 2003. Nat­u­rally oc­cur­ing fatal her­pes sim­plex virus 1 in­fec­tion in a fam­ily of white-faced saki mon­keys (Pithe­cia pithe­cia pithe­cia). Jour­nal of Med­ical Pri­ma­tol­ogy, 32/1: 7-14.

Setz, E., J. En­zweiler, V. Solferini, M. Amen­dola, R. Berton. 1999. Geophagy in the golden-faced saki mon­key (Pithe­cia pithe­cia chrysocephala) in the Cen­tral Ama­zon. Jour­nal of Zo­ol­ogy, 247/1: 91-103.

Setz, E., D. Gas­par. 1997. Scent-mark­ing be­hav­iour in free-rang­ing golden-faced saki mon­keys, Pithe­cia pithe­cia chrysocephala: Sex dif­fer­ences and con­text. Jour­nal of Zo­ol­ogy, 241/3: 603-611.

Suss­man, R., J. Phillips-Con­roy. 1995. A sur­vey of the dis­tri­b­u­tion and den­sity of the pri­mates of Guyana. In­ter­na­tional Jour­nal of Pri­ma­tol­ogy, 16/5: 761-791.

Thoisy, B., J. Gar­don, R. Salas, J. Mor­van, M. Kazanji. 2003. Ma­yaro virus in wild mam­mals, French Guiana. Emerg­ing In­fec­tious Dis­eases, 9/10: 1326-1329.

Thoisy, B., I. Vogel, J. Reynes, J. Pouliquen, B. Carme, M. Kazanji, J. Vie. 2001. Health eval­u­a­tion of translo­cated free-rang­ing pri­mates in French Guiana. Amer­i­can Jour­nal of Pri­ma­tol­ogy, 54/1: 1-16.

Veiga, L., L. Marsh. 2008. "IUCN Red List of Threat­ened Species" (On-line). Pithe­cia pithe­cia. Ac­cessed Feb­ru­ary 23, 2012 at www.​iucnredlist.​org.

Walker, S. 2005. Leap­ing be­hav­ior of Pithe­cia pithe­cia and Chi­ropotes sa­tanas in east­ern Venezuela. Amer­i­can Jour­nal of Pri­ma­tol­ogy, 66/4: 369-387.

War­ren, K., M. Nor­conk. 1993. : Phys­i­cal and chem­i­cal prop­er­ties of fruit and seeds eaten by Pithe­cia and Chi­ropotes; in Suri­nam and Venezuela. In­ter­na­tional Jour­nal of Pri­ma­tol­ogy, 14/2: 207-227.

Wa­ters, S. 1995. A re­view of so­cial pa­ra­me­ters which in­flu­ence breed­ing Pithe­cia pithe­cia in white-faced saki in cap­tiv­ity. In­ter­na­tional Zoo Year­book, 34/1: 147-153.

de Ma­g­a­l­haes, J., J. Costa. 2009. A data­base of ver­te­brate longevity records and their re­la­tion to other life-his­tory traits. Jour­nal of Evo­lu­tion­ary Bi­ol­ogy, 22/8: 1770-1774.