Golden-faced saki, Pithecia chrysocephala
GOLDEN-FACED SAKI
Pithecia chrysocephala
Geographic Distribution and Habitat
The golden-faced saki is found in Brazil, north of the Amazon River. They may be found on both sides of the Negro River, especially in the lower reaches near the city of Manacapuru, and east to the town of Faro along the Nhamunda River.
With regard to habitat, all sakis tend to prefer mature forests. These include variations of flooded forests, namely “várzea” and “igapó”. What do those mean? Both are seasonally flooded forests, but in the simplest terms, differ in the chemical composition of the water by which they are flooded. The golden-faced saki also inhabits palm swamp wetlands and terra firma forests. A terra firma forest is a moist tropical forest that doesn’t experience seasonal floods. Golden-faced sakis can also be found in disturbed habitats and secondary forest fragments. Secondary forests are those which have grown back after a period of human-caused disturbance. Golden-faced sakis can be found in greater density in mature forests.
The golden-faced saki was once considered to be a subspecies of the white-faced saki (P. pithecia), but was designated as a separate species in 2014.
Size, Weight, and Lifespan
The golden-faced saki has a head-body length ranging between 11.22-18.11 inches (285-460 mm) for males, and 11.89-13.11 inches (302-333 mm) for females. The tail ranges in length between 13.39-17.72 inches (340-450 mm) for males and 12.91-15.75 inches (328-400 mm) for females. Their mean weight is an average of 4.19 pounds (1900 g). The difference in size between males and females is an example of sexual dimorphism, which is noticeable physical differences between genders.
Their lifespan in the wild is not known, but their close cousin, the white-faced saki, has a life expectancy of 15 years.
Appearance
Despite their name, only male golden-faced sakis have the signature orange or red-brown facial hair framing their black, naked face, making them easily recognizable. Their facial hair provides a sharp contrast to the rest of the body, which is covered in long black fur. Males also sport a light tan “mustache” over their upper lip. Females, on the other hand, have a lighter body color, and more bare skin on the face. Lines of orange-colored hair extend down from below the eyes around the snout, as well as orange fur along the belly. This difference in appearance is another example of sexual dimorphism.
Their bushy tails are non-prehensile, meaning they are not used for grabbing or grasping, but instead to balance when traveling among the rainforest trees.
Their long, skinny fingers and toes have thick pads on the tips to give them a better hold on branches. The wide gap between the thumb and pointer finger allows them to climb up thick branches and trunks with ease.
Diet
The golden-faced saki’s diet primarily consists of fruits and seeds. They have thick and strong teeth designed to crush seed shells and peel away at unripe fruit. They supplement their diet with young leaves (as opposed to mature leaves, which are more toxic), flowers, and insects.
Behavior and Lifestyle
Golden-faced sakis are diurnal, meaning they are most active during the day. They are also arboreal, preferring to spend their time high up in the trees, and only occasionally descending to the ground. Sakis mostly move on all fours, but sometimes run in an upright position on their hind legs over tree branches. At times, they may also jump long distances between branches. This skill results from the fact that their legs are longer than their arms. All the more perfect to leap with!
According to observation, about 52% of their time is spent traveling around their home range, and 30% of their time is spent foraging. The remaining time budget is spent resting and engaging in social activities, such as grooming and breeding. Nights are dedicated to sleeping, for which golden-faced sakis roll themselves into comfortable cat-like positions among the branches of the trees.
Besides hunting by humans, saki predators include jaguars, ocelots, large birds of prey like the Harpy eagle, and snakes. If we look at the predator-avoidance strategies of the white-faced saki, they vary based on the size of the predator. If they’re facing a large predator, such as a Harpy eagle, they will silently descend out of sight into the lower canopy. If the threat is small, an alarm call will be sounded by a “spotter” saki, which then is continually echoed by others to spread the warning. The sakis will then “mob” the threat, puffing their bodies up to appear larger than they are and stomping their feet on the ground or tree limbs in an attempt to scare the threat away. Don’t mess with the mob!
Undoubtedly shy: Sakis as a whole are a very shy species when encountered by humans. The small range of the golden-faced saki certainly doesn’t help, either, but it just means we have more exciting information to discover about this colorful and charming monkey!
Unlike their white-faced cousins, the golden-faced saki is a little-studied species. According to one study, one group of golden-faced sakis had a home range of 19 acres (7.68 ha), while another had a home range of 21.25 acres (8.60 ha). According to another resource, the golden-faced saki’s average range of daily travel is 0.7 miles (1,115 m) during the dry season, and 0.45 miles (750 m) during the wet season.
Groups of golden-faced sakis typically live in small clusters of two to four individuals, usually consisting of a singular male-female breeding pair, and their immature offspring. However, larger groups of six or more individuals, which may include more than one adult breeding female or male, have been reported. Males and females have been known to leave their natal group once mature.
Sakis in the Amazon have been documented traveling, feeding, and resting with other primates, such as titi monkeys, howler monkeys, squirrel monkeys, spider monkeys, tamarins, and woolly monkeys.
Golden-faced sakis possess a variety of communication methods. Not only do they use vocalizations to warn about predators, but also to establish a territory. These loud, vocal calls are typically performed in pairs by the sole breeding male and female of the group. With regard to other vocalizations, they are known to communicate in grunts, chirps, whistles, and low calls. Territories are also established by scent markers, primarily by males. They will rub glands located on the chest and throat against trees with edible fruit, and mark territory with urine. These glands are also used to excite females and stimulate courtship behavior.
As for whether they respond to alarm calls of other species, or if other animals respond to their alarm calls, further studies are required to make this determination.
Breeding among sakis is non-seasonal and can occur at any time of the year. When the breeding female is receptive, her partner will entice her to breed by scent-marking trees with plenty of yummy fruit. The gestation (pregnancy) period of the golden-faced saki has not been documented, but those of sakis in general range between 150 and 180 days. Afterward, females will give birth to a single offspring. The interval between births is an average of 22 months. It has been observed that during the dry season, births will primarily occur from October to December. During the wet season, births mostly occur from March to April.
Interactions between Dad and offspring are rare, and Mom is the primary caregiver of the young. The baby’s sub-adult female siblings will also help raise the baby, as part of the process of learning how to raise babies of their own in the future. The young are weaned from Mom’s milk after four months and are fully mature in three years. Upon reaching maturity, members of both genders will venture off to form groups of their own.
As frugivores (fruit-eaters), golden-faced sakis aid in the regeneration of their forest habitats by dispersing seeds through their feces as they move around the habitat. They also play a role in pollination. Like bees and butterflies, they collect pollen from flowers when consuming them. They then deposit the pollen on each flower they visit, thereby pollinating the plants. As a prey species, they also play a role in feeding local predators within the habitat. Finally, they can also be considered pest controllers, as a result of their diet consisting of insects.
The International Union for Conservation of Nature lists the golden-faced saki as Least Concern (IUCN, 2015), appearing on the IUCN Red List of Threatened Species.
The main threats facing the golden-faced saki are hunting and habitat loss. With regard to hunting, they are targets for the pet trade, and occasionally their body parts or coats are used for decorative purposes, or even clothing such as hats! A monkey, especially a cute saki monkey, should never be used as a fashion statement! Logging and wood harvesting are the main methods of habitat loss facing the golden-faced saki. If it’s any consolation, the golden-faced saki is rather adaptable and able to live in fragmented and disturbed habitats.
The golden-faced saki is listed in Appendix II of the Convention on International Trade in Endangered Species (CITES), an international agreement between governments whose goal is to ensure that international trade in specimens of wild animals and plants does not threaten their survival.
Unfortunately, the golden-faced saki is not found in any protected areas in Brazil. Conservation actions needed to protect the golden-faced saki include properly enforced protection of the area(s) in which the species is found. Perhaps a protected area can be established by the Brazilian government, or a conservation-focused organization. Additional research on the golden-faced saki would also be welcome, especially since they have been little studied compared to their white-faced cousins. For now, at least, this adaptable species is relatively safe from the plight of endangerment or extinction, but only time will tell how long this will remain true over the coming decades.
- https://www.alltheworldsprimates.org/Members/Home/MasterPrimate.aspx?tid=1339
- https://www.bioexplorer.net/animals/mammals/monkeys/golden-faced-saki/
- https://cites.org/eng/taxonomy/term/1432
- https://en.wikipedia.org/wiki/Golden-faced_saki
- https://en.wikipedia.org/wiki/Igap%C3%B3
- https://en.wikipedia.org/wiki/Saki_monkey
- https://en.wikipedia.org/wiki/Terra_firma
- https://en.wikipedia.org/wiki/V%C3%A1rzea_forest
- https://en.wikipedia.org/wiki/White-faced_saki
- https://www.iucnredlist.org/species/43943/17991938
- https://lazoo.org/explore-your-zoo/our-animals/mammals/white-faced-saki/
- https://radar.brookes.ac.uk/radar/file/1d2af33a-0def-49c1-b2d9-5b2a613b78ea/1/Vocal%20repertoire%20of%20golden-faced%20saki%20-%202019%20-%20Muir%20Barnett%20Svensson.pdf
Written by Sienna Weinstein, October 2024