Diversity
        The genus
        
         Pithecia
        
        , more commonly known as Saki monkeys, are New World Monkeys native to neotropical
            South America. There are currently 16 described species and can be found throughout
            tropical rainforests in the Amazon Basin.
        
         Pithecia
        
        are medium-sized primates that are characterized by their long, thick fur that covers
            their whole body. Their tales are non-prehensile and are often at a 1:1 ratio with
            their body. The genus prefers mature forests and they spend the majority of their
            time foraging in the canopy, and trips to the forest floor are rare. Their conservation
            status is unknown as they are very elusive in the wild, but their population is expected
            to be in decline due to increasing habitat loss.
        
Geographic Range
        Saki monkeys are distributed across neotropical South America in tropical forests
            in the Amazon Basin. They range as far north as the Guiana Shield and as far south
            as Northern Bolivia.
        
- Biogeographic Regions
- neotropical
Habitat
        Saki monkeys are arboreal and spend all their time in the canopy. While they can be
            found in secondary forests, they are more likely to persist in mature forests with
            variable habitat including terra firme, palm swamps, and flooded forest. Their large
            geographic distribution is attributed to their ability to persist in a range of forests
            types.
            Sakis are diurnal and sleep in trees at different designated sleeping spots during
            the night. They are very elusive and rarely ever venture to the forest floor.
        
- Habitat Regions
- tropical
- Terrestrial Biomes
- rainforest
Systematic and Taxonomic History
        The genus
        
         Pithecia
        
        consists of about 16 recognized species. The taxonomy of this genus has been widely
            difficult to establish due to a lack of genetic information, misuse of common names,
            misunderstandings of sexual dimorphism, and imprecise type localities. In a taxonomic
            review of the genus in 2019, researchers found evidence for two morphologically diagnosable
            groups within genus
        
         Pithecia
        
        (
        
         P. irrorata
        
        and
        
         P. vanzolinii
        
        ).The taxonomic uncertainty within the genus
        
         Pithecia
        
        proves that more studies need to be done to evaluate the revise the taxonomic status
            of genus.
        
Physical Description
        Saki monkeys are medium sized primates and the smallest of the
        
         Pitheciidae
        
        family. Sakis have a wide range in body length and their tails are often a 1:1 ratio
            with their body length. Females are slightly smaller than males in overall size and
            weight. Sakis have long, rough hair that covers their entire body, giving them a distinct
            shaggy look and oftentimes they appear to have "bangs." Sexual dimorphism varies among
            species but males and females generally have distinct pelage markings. Both sexes
            have throat glands that are used for scent marking. Sakis do not have prehensile tails
            and they can be seen walking, running, climbing, and leaping as their main form of
            locomotion.
        
- Other Physical Features
- endothermic
- bilateral symmetry
- Sexual Dimorphism
- male larger
- sexes colored or patterned differently
Reproduction
        Species in the genus
        
         Pithecia
        
        live in monogamous social groups. While not much information is known on their reproductive
            behaviors in the wild, captive populations have been shown to be more monogamous than
            wild populations. Larger groups tend to be polygamous or polyandrous given more than
            one primary breeding female and male are present in the group.
        
- Mating System
- monogamous
- polyandrous
- polygynous
        During mating season, male saki monkeys make mating calls to the females in wild populations.
            Both males and females become sexually mature at around three years of age, but females
            can take longer, given the time their ovarian cycle becomes regular. Females typically
            bear only one offspring and the gestation period lasts on average 146 days.
        
- Key Reproductive Features
- seasonal breeding
- gonochoric/gonochoristic/dioecious (sexes separate)
- sexual
        Infant saki monkeys will cling to the mother's thigh for the first month of their
            life. Then they relocate to the mothers back for the next three months which allows
            for better mobility given the size of the growing infant. Once the infant reaches
            the age of about five months, it stops clinging from its mother and moves freely within
            the group. The offspring still weans from its mother until it can survive on its own.
        
- Parental Investment
- female parental care
- 
         
          pre-fertilization
         
         - provisioning
- 
           
            protecting
           
           - female
 
 
- 
         
          pre-hatching/birth
         
         - 
           
            provisioning
           
           - female
 
- 
           
            protecting
           
           - female
 
 
- 
           
            provisioning
           
           
- 
         
          pre-weaning/fledging
         
         - 
           
            provisioning
           
           - female
 
- 
           
            protecting
           
           - female
 
 
- 
           
            provisioning
           
           
- 
         
          pre-independence
         
         - 
           
            provisioning
           
           - female
 
- 
           
            protecting
           
           - female
 
 
- 
           
            provisioning
           
           
- extended period of juvenile learning
Lifespan/Longevity
        While not much is known on the longevity of most
        
         Pithecia
        
        species, some species can live up to 36 years in captivity, but the average lifespan
            among sakis in the wild is around 15 years.
        
Behavior
        Saki monkeys are social and travel through the canopy in small groups of 2 to 9 individuals.
            Their daily activities include moving from sleep trees in early morning to forage
            for fruit, then returning to another sleep tree in the evening, often accompanied
            by another saki monkey group. Sakis spend anywhere from 9 to 12 hours moving through
            the canopy. Allogrooming is practiced extensively throughout the day and is most commonly
            seen between mothers and infants. Saki monkeys have a variety of specialized vocalizations
            including trills, whistles, grunts, roars, and squeaks, which are used for various
            intensity dependent aggressions.
        
- Key Behaviors
- arboreal
- scansorial
- saltatorial
- diurnal
- motile
- sedentary
- territorial
- social
Communication and Perception
        Sakis communicate to each other and to other groups by loud vocalizations, and often
            establish their territories when male and female pairs, typically the breeding individuals,
            make loud calls. Sakis have scent glands on their chests/throats and adult males mark
            their territory using a combination of urine and scent gland markers.
        
- Other Communication Modes
- duets
- pheromones
- scent marks
- vibrations
- Perception Channels
- visual
- tactile
- acoustic
- vibrations
- chemical
Food Habits
        Species in the genus
        
         Pithecia
        
        are specialized for eating the seeds of fruiting bodies. Apart from seeds they consume
            fruits, flowers, leaves, and nuts. Leaves are eaten more often in the dry season when
            fruit is not available. Since their diet lacks protein, they have been known to eat
            insects to make up for their high fat intake.
        
Predation
        Saki monkeys make alarm calls when a predator is near the group. Once the first alarm
            call is made, the rest of the group joins. The group stays motionless after making
            the call so they are undetectable within the canopy, then they move away from the
            threat. Sakis have both terrestrial predators like jaguars and anacondas, as well
            as avian predators like the harpy eagle.
        
- Anti-predator Adaptations
- aposematic
- cryptic
Ecosystem Roles
        Sakis play a major role in seed dispersal. Some species of sakis, including
        
         Pithecia pithecia
        
        , have been recorded for having parasites like roundworm, heartworm, and the Mayaro
            virus.
        
- Ecosystem Impact
- disperses seeds
Economic Importance for Humans: Positive
        Sakis are commonly hunted and captured for their meat in the Amazon basin. They are
            also trapped for the pet trade, although they don't live long when kept as a pet because
            their diet requirements are hard to meet. While there are only a handful of Pithecia
            species in captivity, they attract many visitors in zoos. Sakis that have been habituated
            near hotels and ecolodges in the Amazon are also big tourist attractions.
        
Economic Importance for Humans: Negative
        The adverse effects saki monkeys have on humans is unknown. Studies have shown that
            sakis can carry diseases that can be transmitted to humans, including the human herpesvirus
            (HHVI) and hepatitis.
        
- Negative Impacts
- 
         
          injures humans
         
         - carries human disease
 
- causes or carries domestic animal disease
Conservation Status
        The conservation status of most saki monkeys are of least concern, but there is a
            data deficiency for almost all saki species, including
        
         Pithecia irrorata
        
        ,
        
         Pithecia milleri
        
        , and
        
         Pithecia rylandsi
        
        , and current populations are unknown. However, increasing habitat loss and fragmentation
            due to deforestation and gold mining in the Amazon is assumed to be causing a rapid
            decline in their populations.
        
Additional Links
Contributors
Sierra Larson (author), Colorado State University, Audrey Bowman (editor), Colorado State University.
- Neotropical
- 
          living in the southern part of the New World. In other words, Central and South America.   
- native range
- 
          the area in which the animal is naturally found, the region in which it is endemic. 
- tropical
- 
          the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south. 
- rainforest
- 
          rainforests, both temperate and tropical, are dominated by trees often forming a closed canopy with little light reaching the ground. Epiphytes and climbing plants are also abundant. Precipitation is typically not limiting, but may be somewhat seasonal. 
- monogamous
- 
          Having one mate at a time. 
- polyandrous
- 
          Referring to a mating system in which a female mates with several males during one breeding season (compare polygynous). 
- polygynous
- 
          having more than one female as a mate at one time 
- seasonal breeding
- 
          breeding is confined to a particular season 
- sexual
- 
          reproduction that includes combining the genetic contribution of two individuals, a male and a female 
- female parental care
- 
          parental care is carried out by females 
- arboreal
- 
          Referring to an animal that lives in trees; tree-climbing. 
- saltatorial
- 
          specialized for leaping or bounding locomotion; jumps or hops. 
- diurnal
- 
          - active during the day, 2. lasting for one day.
 
- motile
- 
          having the capacity to move from one place to another. 
- sedentary
- 
          remains in the same area 
- territorial
- 
          defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement 
- social
- 
          associates with others of its species; forms social groups. 
- visual
- 
          uses sight to communicate 
- tactile
- 
          uses touch to communicate 
- acoustic
- 
          uses sound to communicate 
- chemical
- 
          uses smells or other chemicals to communicate 
- duets
- 
          to jointly display, usually with sounds in a highly coordinated fashion, at the same time as one other individual of the same species, often a mate 
- pheromones
- 
          chemicals released into air or water that are detected by and responded to by other animals of the same species 
- scent marks
- 
          communicates by producing scents from special gland(s) and placing them on a surface whether others can smell or taste them 
- vibrations
- 
          movements of a hard surface that are produced by animals as signals to others 
- visual
- 
          uses sight to communicate 
- tactile
- 
          uses touch to communicate 
- acoustic
- 
          uses sound to communicate 
- vibrations
- 
          movements of a hard surface that are produced by animals as signals to others 
- chemical
- 
          uses smells or other chemicals to communicate 
- aposematic
- 
          having coloration that serves a protective function for the animal, usually used to refer to animals with colors that warn predators of their toxicity. For example: animals with bright red or yellow coloration are often toxic or distasteful. 
- cryptic
- 
          having markings, coloration, shapes, or other features that cause an animal to be camouflaged in its natural environment; being difficult to see or otherwise detect. 
- pet trade
- 
          the business of buying and selling animals for people to keep in their homes as pets. 
- food
- 
          A substance that provides both nutrients and energy to a living thing. 
- causes or carries domestic animal disease
- 
          either directly causes, or indirectly transmits, a disease to a domestic animal 
- carnivore
- 
          an animal that mainly eats meat 
- insectivore
- 
          An animal that eats mainly insects or spiders. 
- herbivore
- 
          An animal that eats mainly plants or parts of plants. 
- folivore
- 
          an animal that mainly eats leaves. 
- frugivore
- 
          an animal that mainly eats fruit 
- granivore
- 
          an animal that mainly eats seeds 
- endothermic
- 
          animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds. 
- bilateral symmetry
- 
          having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria. 
References
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Bauer, K., J. Steeil, E. Adkins, A. Childress, J. Wellehan, K. Kerns, S. Sarro, K. Holder. 2018. Management of Ocular Human herpesvirus 1 infection in a White-faced Saki Monkey (Pithecia pithecia). Comparative Medicine , 1/68(4): 319-323.
Eduardo Serrano-Villavicencio, J., C. Hurtado, R. Vendramel, F. Do Nascimento. 2019. Reconsidering the taxonomy of the Pithecia irrorata species group (Primates: Pitheciidae).. Journal of Mammalogy , 100: 130-141.
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Marsh, L. 2014. A Taxonomic Revision of the Saki Monkeys, Pithecia Demarest, 1804.. Neotropical Primates , 21: 1-163.
Norconk, M., N. Conklin-Brittain. 2004. Variation on frugivory: The diet of Venezuelan white-faced Sakis. International 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 Eat or be eaten: predator sensitive foraging among primates . Cambridge, United Kingdom: Press Syndicate of the University of Cambridge.
Norconk, M. 2006. Long-term Study of Group Dynamics and Female Reproduction in Venezuelan Pithecia pithecia. International Journal of Primatology , 27: 653-674.
Nowak, R. 1991. Walker's Mammals of the World, Volume 1 . Baltimore: The Johns Hopkins University Press.
Palminteri, S., C. Peres. 2012. Habitat Selection and Use of Space by Bald-Faced Sakis (Pithecia irrorata) in Southwestern Amazonia: Lessons from a Multiyear, Multigroup Study. International Journal of Primatology , 33/2: 401-417.
Palminteri, S., G. Powell, C. Peres. 2016. Determinants of Spatial Behavior of a Tropical Forest Seed Predator: The Roles of Optimal Foraging, Dietary Diversification, and Home Range Defense.. American Journal of Primatology , 78/5: 523-533.
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.
Walker, S. 2005. Leaping behavior of Pithecia pithecia and Chiropotes satanas in eastern Venezuela. American Journal of Primatology , 66/4: 369-387.
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.
