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.
Communication Channels: visual ; tactile ; acoustic ; chemical
Other Communication Modes: duets ; pheromones ; scent marks ; vibrations
Perception Channels: visual ; tactile ; acoustic ; vibrations ; chemical
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.
US Federal List: no special status
CITES: appendix ii
State of Michigan List: no special status
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.
Negative Impacts: injures humans (carries human disease); causes or carries domestic animal disease
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.
Positive Impacts: pet trade ; food ; body parts are source of valuable material
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).
Ecosystem Impact: disperses seeds
Commensal/Parasitic Species:
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.
Animal Foods: insects
Plant Foods: leaves; seeds, grains, and nuts; fruit; flowers
Primary Diet: herbivore (Folivore , Frugivore , Granivore )
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.
Biogeographic Regions: neotropical (Native )
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.
Habitat Regions: tropical ; terrestrial
Terrestrial Biomes: rainforest
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.
Range lifespan
Status: captivity: 36 (high) years.
Average lifespan
Status: wild: 15 years.
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).
Average mass: 1.871 kg.
Sexual Dimorphism: male larger; sexes colored or patterned differently; male more colorful
Other Physical Features: endothermic ; bilateral symmetry
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.
Known Predators:
Anti-predator Adaptations: aposematic
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.
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.
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.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; viviparous
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.
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
The white-faced saki (Pithecia pithecia), called the Guianan saki and the golden-faced saki, is a species of the New World saki monkey. They can be found in Brazil, French Guiana, Guyana, Suriname and Venezuela. This species lives in the understory and lower canopy of the forest, feeding mostly on fruits, nuts, seeds, and insects. Although they are arboreal creatures and are specialists of swinging from tree to tree (brachiation), they are also terrestrial when foraging. White-faced sakis typically live around 14 years in their natural habitat and have been recorded to live up to 36 years in captivity. Sakis are active in the day and sleep highly elevated (15-20m) in trees with many leaves to shelter them from weather and flying predators.[3]
A formerly recognized subspecies of this monkey, P. p. chrysocephala,[4] was elevated to full species status as P. chrysocephala in 2014.[5]
In captivity, female white-faced sakis experience ovarian cycles of approximately 17 days, and a gestational period of 20–21 weeks. Following birth, the mother undergoes a period of lactationally-induced infertility lasting 23 weeks, on average.[6] White faced sakis breed once a year (in the spring) and only have one offspring.[3]
White-faced sakis display noticeable sexual dimorphism in their coloration and also in size. Females have shorter hair than males, with brownish-grey fur and white or pale brown stripes around the corners of the nose and mouth. Males, on the other hand, have blacker fur, with a reddish-white forehead, face, and throat. Their faces are much whiter than females and males are larger in body size.[5][3] Males are approximately 500 grams heavier than females.[7] Young saki males are often identified as females because of their sometimes "grizzling" dorsal hair and orangish bellies and it is approximately 2 months of age when males and females being to show differences, although it gradually becomes obvious over a few years.[5]
A pair often mates for life, and they are very devoted to one another. They will strengthen their bond by grooming one another. Male saki monkeys are usually more active than females. They are considered monogamous, but have seldom been observed over a long period of time and many primatologists question their behavior as being "typical monogamy" because of their inconsistent group numbers and possible seasonal effect on congregations. A South American study performed by Shawn M. Lehman shows that their group number can range from 2-12 group members, with higher numbers typically occurring (but not exclusively) in Guyana, South America.[8] But most widespread observations conclude that they travel in small groups of 2 and 3 which usually include the bonded parents and the offspring; they travel approximately 0.5 to 1.25 miles in search of food or other resources during the early morning and day, when they are most active.[9][7]
White faced sakis vary from many other primates including their close relative, Chiropotes satanas, in that they are predominantly leapers, which is how they travel approximately 70 percent of the time. The other 30 percent is spent quadrupedal walking and running (25 percent) and climbing (less than 5 percent).[10]
These primates travel longer distances than many other primates and can be picky about their sources of food; they prefer trees that produce high amounts of fruit, Capparis trees, and trees with water holes.[11] Sakis have a mixed diet of seeds, fruits, leaves, honey, flowers, insects, and small mammals and birds and typically ingest seeds and plants that are high in lipid composition.[12][7] They have also been observed crawling into hollow portions of trees and eating bats where they roost. They are capable of doing so due to their large canine teeth which assist in cracking the hard outer covering of shells and nuts.[7]
If a predator is near, alarm calls, which have been observed to last from 1.2 to 88 minutes, will be sounded by an initial saki and then continually echoed by others to spread the warning. They will then puff their bodies up and stomp their feet on the ground or trees in an attempt to intimidate the threat.[7][9] They are small primates and dwell in the branches of trees, so one of their biggest predator threats are large birds such as hawks, vultures, and the harpy eagle. In the face of danger, white faced sakis will emit warning calls to others or freeze if in the canopy in an attempt to move down where they are out of sight. The predator response of the sakis are due to what type of threat they are facing: if a smaller, easily overpowered threat, the group will participate in a behavior called "mobbing" to scare the predator away, but if the threat is larger, such as an eagle, they will refrain from warning calls and descend out of sight into the lower canopy. Other terrestrial and aquatic predators include the tayra, jaguars, pumas, green anacondas, ocelots, red-tailed boa, and even large mustelids, which are usually threats to the young and elderly.[9]
The white-faced saki (Pithecia pithecia), called the Guianan saki and the golden-faced saki, is a species of the New World saki monkey. They can be found in Brazil, French Guiana, Guyana, Suriname and Venezuela. This species lives in the understory and lower canopy of the forest, feeding mostly on fruits, nuts, seeds, and insects. Although they are arboreal creatures and are specialists of swinging from tree to tree (brachiation), they are also terrestrial when foraging. White-faced sakis typically live around 14 years in their natural habitat and have been recorded to live up to 36 years in captivity. Sakis are active in the day and sleep highly elevated (15-20m) in trees with many leaves to shelter them from weather and flying predators.
A formerly recognized subspecies of this monkey, P. p. chrysocephala, was elevated to full species status as P. chrysocephala in 2014.
