Family Pitheciidae
titi monkeys, sakis, and uakaris

There are 40 species in the family Pitheciidae, commonly known as titi monkeys, sakis, and uakaris. The most diverse genus in this family is Callicebus, the titi monkeys, with 28 species. There are 5 species of saki monkeys (Pithecia), 5 species of bearded saki monkeys (Chiropotes), and 2 species of uakaris (Cacajao). (Wilson and Reeder, 2005)

Titis, sakis, and uakaris are found in the rainforests of South America, including the Amazon and Orinoco river basins and the Atlantic coastal forest of southeastern Brazil. (Grafton, 2004; Nowak, 1991)

Titis and sakis are highly arboreal and found in a wide variety of forests, including highland and lowland forests, dry forests, varzea, savanna forests, liana forests, swamps, inundated forests, and forests along river and lake edges. Chiropotes and Cacajao species are restricted to fewer forest types, including terra firme and higher elevation moist and savanna forests. (Grafton, 2004; Nowak, 1991)

Pitheciidae genera were previously considered part of the large, New World monkey family Cebidae. They are now considered a monophyletic family made up of two subfamilies: Callicebinae, the titi monkeys, and Pitheciinae, including sakis, bearded sakis, and uakaris. (Wilson and Reeder, 2005)

Recent taxonomic revisions of pitheciine genera has led to a large increase in the number of recognized species. Before a 1990 revision by Hershkovitz, only 3 species of Callicebus were recognized. Currently, 28 species are recognized. (Groves, 2001; Hershkovitz, 1990; Nowak, 1991; Ryder et al., 2005; Seuanez et al., 1999; Steiper and Ruvolo, 2003; Wilson and Reeder, 2005)

Titis, sakis, and uakaris are small to medium-sized monkeys. Titis (Callicebus) are the smallest and uakaris (Cacajao) are the largest. The four pitheciine genera are distinct in appearance, but all share a common dental morphology marked by large, laterally splayed canine teeth separated from the incisors by a diastema. The incisors are also angled forward and the molars have low, crenulated occlusal surfaces. This dental morphology is an adaptation to eating hard, heavily protected fruits. Uakaris (Cacajao) and bearded sakis (Chiropotes) are sexually dimorphic and several saki monkey species (Pithecia) are sexually dichromatic. Pelage color varies from light and thin, in uakaris to dark and woolly in bearded sakis. Uakaris (Cacajao) are the most unusual looking pitheciines, with largely naked faces and heads and short tails, they sometimes have a nearly bald appearance as well. (Grafton, 2004; Nowak, 1991)

Head and body length is 230 to 460 mm in Callicebus, 300 to 705 mm in Pithecia, 327 to 511 mm in Chiropotes, and 300 to 579 mm in g.Cacajao. Tail length is 260 to 560 mm in <<g.Callicebus, 255 to 545 mm in Pithecia, 300 to 507 mm in Chiropotes, and 125 to 210 mm in Cacajao. Callicebus species weigh up to 2 kg, Pithecia species weigh 0.7 to 1.7 kg, Chiropotes species weigh 2 to 4 kg, and Cacajao species weight from 2.7 to 3.5 kg. (Nowak, 1991)

Titis (Callicebus), the smallest of the pitheciids, have lived more than 25 years in captivity. Uakaris (Cacajao) have lived more than 31 years in captivity and sakis (Pithecia) up to 35 years. Bearded sakis (Chiropotes) are estimated to live more than 18 years in the wild. (Nowak, 1991)

Titis, sakis, and uakaris are all diurnal and social monkeys. All are highly arboreal, only rarely coming to the ground. All species use mainly quadrupedal locomotion in the trees, but uakaris (Cacajao) sometimes also employ leaps and bipedal suspension. Sakis and bearded sakis (Pithecia and Chiropotes) have relatively smaller ranges than do the other genera, from 1 to 4.5 km. Uakaris range up to 5 km in a day. (Grafton, 2004; Nowak, 1991)

All pitheciid species live in small groups. Titis live in family groups made up of a mated pair and and their offspring. Other genera live in multi-male, multi-female groups of various sizes, from 10 to 30 in Chiropotes to groups of up to 100 in Cacajao. Territories are defended but there can also be extensive overlap in home ranges of adjacent groups. Territories are most often defended with vocalizations. (Grafton, 2004; Nowak, 1991)

Titis, sakis, and uakaris use vocalizations extensively to communicate with conspecifics and defend territorial boundaries. Titi pairs are the most territorial and males emit loud vocalizations to advertise territorial boundaries. Male and female duets are also used to communicate territorial boundaries. Grooming is very important in reinforcing social bonds. In titis (Callicebus) individuals sit together with their tails entwined and may spend up to 10% of their time grooming each other. Chiropotes and Cacajao species exhibit a tail-wagging behavior that shows excitement. Red uakaris, Cacajao calvus, have one of the widest ranges of facial expressions in primates. (Grafton, 2004; Nowak, 1991)

Titis, sakis, and uakaris are all specialized for eating large, hard fruits, often to get at the seeds within. Titis (Callicebus) eat more fruit pulp than other genera. Sakis and uakaris eat mainly large, indehiscent fruits with few large seeds, such as brazil nuts. Pitheciid species also supplement their diet with leaves and insects. (Grafton, 2004; Nowak, 1991)

Titis, sakis, and uakaris may be preyed on by large diurnal raptors, who hunt above forest canopies.

Titis, sakis, and uakaris may help disperse the seeds of some of the fruits they eat.

There are no known adverse effects of titis, sakis, and uakaris on humans. (Nowak, 1991)

Titis, sakis, and uakaris are hunted for meat and captured for the pet trade. They are important members of native forest ecosystems and can be important in drawing ecotourism interest in an area. (Groves, 2001; Nowak, 1991)

Two species of titi monkeys (Callicebus) are critically endangered, C. barbarabrownae and C. coimbrai, both are known only from small forest fragments. Brown bearded sakis, Chiropotes satanus, are endangered as a result of forest fragmentation. All members of Pitheciidae are on CITES Appendix II. (International Union for the Conservation of Nature, 2007)