SAKIS, TITIS, AND UAKARIS: Pitheciidae

PHYSICAL CHARACTERISTICS

Pitheciids (PITH-uh-sidz; members of the family Pitheciidae) are small- to medium-sized monkeys, ranging from the smallest, the titis, to the largest, the uakaris. Male bearded sakis and uakaris are about 20 percent larger than the females. Male and female white-faced sakis differ in coloration. The bald uakari is easily recognized by its pinkish to bright red naked face. All pitheciid species have long coats, except for the short-furred bearded saki. The bald uakari alone has a short tail, about a third of its body length. The rest of the species have long, nonprehensile (nongrasping) tails.

GEOGRAPHIC RANGE

Pitheciids are found in Bolivia, Brazil, Colombia, Ecuador, French Guiana, Guyana, Peru, and Suriname.

HABITAT

Pitheciids inhabit a variety of rainforest habitats. Sakis prefer the middle and lower layers of the canopy, as well as the understory. They are found in savanna forests, mountain forests, swamps, and forests along rivers, but not flooded forests. Uakaris choose forests that get flooded from seasonal rainfall for about six months. Titis occupy coastal forests, living in the understory.

DIET

Sakis and uakaris feed mainly on seeds, especially from tough-skinned fruits, while titis prefer fruit pulps. All species supplement their diet with flowers, leaves, shoots, and insects.

BEHAVIOR AND REPRODUCTION

Pitheciids differ in the size of their social groups, ranging from small parent-and-offspring groups among titis to the uakari multimale-multifemale groups of up to 100 members. They are mostly arboreal, living in the trees of the forest canopy and understory. Active during the day, these primates take breaks for mutual grooming. Pitheciids are vocal and use body postures to communicate, such as erecting the body hair to show aggression.

All pitheciids give birth to one infant. Some species breed seasonally, while others do not. Saki fathers do not help with child care but do groom infants. Titi fathers are the principal caregivers, even of older offspring. The young are weaned at different ages, with sakis being independent at about age one and titis remaining with the parents until they are two or three years old.

PITHECIIDS AND PEOPLE

Pitheciids are hunted for food and trapped for the pet trade. Sakis are hunted for their long, bushy tails that are made into dusters.

DE-STRESSING

Sakis, uakaris, and titis, like many primates, practice mutual grooming. They take turns looking through each other's fur, carefully removing dirt, dead skin, and parasites. The parasites are usually eaten by the groomer. These primates seem to have found a way not only to de-stress but also to practice hygiene (HIGH-jeen) and reinforce social bonds.

CONSERVATION STATUS

The World Conservation Union (IUCN) lists Barbara Brown's titi and Coimbra's titi as Critically Endangered, facing an extremely high risk of extinction, due to habitat loss or degradation from logging. The bearded saki is classified as Endangered, facing a very high risk of extinction, because of hunting and pet collection, as well as habitat loss from deforestation. Six other species are listed as Vulnerable, facing a high risk of extinction, and two species as Near Threatened, not currently threatened, but could become so, due to several factors, including hunting, capture for the pet trade, and habitat loss from deforestation for timber and agriculture.

WHITE-FACED SAKI (Pithecia pithecia):SPECIES ACCOUNTS

Physical characteristics: The white-faced saki weighs 1.8 to 5.5 pounds (0.8 to 2.5 kilograms). It measures 13.2 to 13.8 inches (33.5 to 35 centimeters), with a tail length of 13.5 to 17.5 inches (34.3 to 44.5 centimeters). The coarse fur is long, thick, and shaggy, making the animal seem larger. The saki is named for its white facial coloration, sometimes tinged with red, which is typical only of males. Females have black or brownish fur, with a pale stripe running down from under the eyes to each side of the face. This marked color difference is unusual in primates. Long nape hair flows forward like a hood. The black nose is very wide, and the nostrils are flat. The long, bushy tail is non-prehensile, or incapable of grasping. It is used for balance when traveling through the forest.

Geographic range: White-faced sakis are found in Bolivia, Brazil, Colombia, Ecuador, French Guiana, Guyana, Peru, and Suriname.

Habitat: White-faced sakis inhabit savanna forests where grassland and forest meet, as well as mountain forests. They live in palm swamps and forests along rivers, although they do not like flooded areas. They prefer the middle and lower levels of the forest canopy but will forage at the tangled vegetation below.

Diet: White-faced sakis feed mainly on seeds, fruits, flowers, shoots, and leaves. They occasionally eat birds, termites, and other insects. They sometimes catch mice and bats, which they skin and tear to pieces before eating.

Behavior and reproduction: White-faced sakis are active during the day, sleeping at night curled up on branches. They are agile climbers, traveling and climbing on all fours. They are known as the flying monkeys because of their ability to jump downward through forest gaps of up to 33 feet (10 meters). Sakis also travel upright on their hind feet. They show aggression by arching their back, erecting their fur, and shaking their body. Sakis communicate using loud calls, chirps, and high-pitched whistling.

Sakis live in small groups of up to five individuals, typically the parents and their young. Larger groups may get together at abundant food sources. Females give birth to a single infant from December to April. All infants are born with female colorations. Males acquire their striking facial coloration at two months. The mother alone rears the young, who leave home at age one.

White-faced sakis and people: White-faced sakis are hunted for food and collected for the pet trade.

Conservation status: The white-faced saki is not considered a threatened species. ∎

BALD UAKARI (Cacajao calvus):SPECIES ACCOUNTS

Physical characteristics: The bald uakari has long, coarse, shaggy hair that varies in coloration from white to red to reddish gold to orange. The bald face is pink to bright red. It is thought that the red face is an indication to a potential mate that the individual is healthy. Malaria is a common disease in the Amazon rainforest, and uakaris afflicted with the disease tend to have paler faces. Sharp incisors, canine teeth, and powerful jaws are especially adapted for piercing and cracking the hard shells of fruits and extracting the seeds, their favorite food. Bald uakaris weigh about 6.6 to 7.7 pounds

(3 to 3.5 kilograms) and measure about 21.3 to 22.4 inches (54 to 57 centimeters), with a tail length of 5.9 to 6.3 inches (15 to 16 centimeters). It is the only South American monkey with a short tail.

Geographic range: Bald uakaris are found in Brazil, Colombia, and Peru.

Habitat: Bald uakaris prefer flooded rainforests along small rivers. Seasonal rainfall, which can last six or more months, causes water to cover as much as 33 feet (10 meters) of tree trunks, so the uakaris remain in the trees during that time.

Diet: Bald uakaris are seed specialists, preferring the seeds found in unripe fruits and those with hard skins that abound in flooded rainforests. They eat young saplings on the ground when the waters dry up. They also feed on flowers, insects, and snails.

Behavior and reproduction: Bald uakaris generally live in groups of ten to thirty individuals. Large groups consisting of up to 100 individuals form smaller groups when foraging. Uakaris sleep at night in the forest canopy. They travel on four limbs and also leap through the forest, although they are not expert leapers. When feeding, they sometimes suspend themselves in the air using their limbs.

Uakaris have several mating partners. Females have single births every two years, caring for the infants themselves. The mother carries the newborn on her front during the first three or four months, after which she carries it on her back. Infants are weaned by twenty-one months.

Bald uakaris and people: Bald uakaris are hunted for food and collected as pets.

Conservation status: The IUCN lists the bald uakari as Near Threatened due to continued hunting for food and trapping for the pet trade. ∎

MASKED TITI (Callicebus personatus): SPECIES ACCOUNTS

Physical characteristics: The masked titi weighs 0.9 to 3.6 pounds (1 to 1.7 kilograms). It measures 12.2 to 16.5 inches (31 to 42 centimeters), with a tail length of 16.5 to 21.7 inches (41.8 to 55 centimeters). The long, soft, hairy coat is grayish to yellowish or orange. The face, hands, and feet are black. The non-prehensile tail is long and bushy.

Geographic range: Masked titis are found in Brazil.

Habitat: Masked titis prefer coastal forests. They are found in dense understory vegetation up to 33 feet (10 meters) high. They also inhabit banana groves.

Diet: Masked titis feed on unripe fruits, leaves, flowers, and insects.

Behavior and reproduction: Masked titis are active during the day. At dawn, neighboring groups emit loud calls, usually initiated by the mated pair, announcing ownership of a certain territory. Titis defend their territory, chasing away intruders. They move through the forest canopy on all fours. They intertwine their tails when sleeping, resting, or sitting on tree branches.

Titis mate for life, producing a single infant annually. The family group consists of two to seven individuals, typically the parents and offspring of different ages. The father almost exclusively rears the infant, carrying it on his back and giving it to the mother just to nurse. The father is known to move the infant to his underside to protect it from the rain. He also rears the older offspring, grooming them, guarding them from predators, and sharing his food with them. The mother does not share her food with the young. The young leave their home at ages two to three.

Masked titis and people: Masked titis are hunted for food and collected as pets.

Conservation status: The IUCN lists the masked titi as Vulnerable due to hunting and trapping by humans, as well as habitat loss and degradation from logging. ∎

FOR MORE INFORMATION

Books:

Kavanagh, Michael. A Complete Guide to Monkeys, Apes and Other Primates. New York: The Viking Press, 1983.

Kinzey, Warren G., ed. New World Primates: Ecology, Evolution, and Behavior. New York: Aldine de Gruyter, 1997.

Napier, John R., and Prue H. Napier. The Natural History of the Primates. Cambridge, MA: The MIT Press, 1986.

Nowak, Ronald M. Walker's Primates of the World. Baltimore: The Johns Hopkins University Press, 1999.

Preston-Mafham, Rod, and Ken Preston-Mafham. Primates of the World. New York: Facts on File, Inc., 1992.

Periodicals:

Jones, Clyde, and Sydney Anderson. "Callicebus moloch." Mammalian Species 112 (December 29, 1978): 1–5.

Web sites:

Heilhecker, Ellen, and Chris Yahnke. "Callicebus personatus (Masked Titi)." Animal Diversity Web. http://animaldiversity.ummz.umich.edu/site/accounts/information/Callicebus_personatus.html (accessed July 6, 2004).

"What's Out There in the Primate World?" Investigate Biodiversity. http://investigate.conservation.org/xp/IB/speciesdiversity/ (accessed July 6, 2004).

"White-faced Saki." Como Park Zoo & Conservatory. http://www.comozooconservatory.org/zoo/saki.htm (accessed July 6, 2004).