I plan to:

  1. add more general knowledge in the "introductory part"
  2. add the diet topic and discuss the specifics of what they eat
  3. add more information about the behavior and "seasonal variations"
  4. add information about predator risks and adaptions
  5. add more about the sexual dimorphism

Possible sources:

Cunningham, E. & Janson, C. Anim Cogn (2007) 10: 293. doi:10.1007/s10071-007-0077-4

Primatologists, Women. "Variations in group size in white-faced sakis (Pithecia pithecia): evidence for monogamy or seasonal congregations?." Neotropical primates 9.3 (2001): 96.

Norconk M (1996) Seasonal variation in the diets of white-faced sakis (Pithecia pithecia and Chiropotes satanas) in Guri Lake, Venezuela. In: Norconk M, Rosenberger A, Garber P (eds) Adaptive radiations of neotropical primates. Plenum, New York pp 403–425

Norconk M, Conklin-Brittain NL (2004) Variation on frugivory: the diet of Venezuelan white-faced sakis. Int J Primatol 25:1–26

Hershkovitz, P. 1979. The species of sakis, genus Pithecia (Cebidae, Platyrrhini), with notes on sexual dichromatism. Folia Primatol. 31: 1–22.

Gleason T, Norconk M (2002) Predation risk and antipredator adaptations in white-faced sakis, Pithecia pithecia. In: Miller L (ed) Eat or be eaten: predator sensitive foraging among primates. Cambridge University Press, New York pp 211– 227

The white-faced saki (Pithecia pithecia), also known as the Guianan saki and the golden-faced saki, is a species of saki monkey, a type of New World monkey, 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, but also eating nuts, seeds, and insects. Although they are aboreal creatures and are specialists of swinging from tree to tree (brachiation), they are also terrestrail 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 lots of leaves to shelter them from weather and flying predators. [11] 

A formerly recognized subspecies of this monkey, P. p. chrysocephala,[3] was elevated to full species status as P. chrysocephala in 2014.[4]

Reproduction

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Female (left) and male P. pithecia, illustrating sexual dimorphism in coat coloration

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.[5]

White-faced sakis display noticeable sexual dichromism in their coloration. 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. [6] [4]

Although it differs among regions and age, young saki males are often identified as females because of their sometimes "grizzling" dorsal hair and orangish bellies, while others resemble typical male appearance.[4]

Behavior

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A pair often mates for life. They are very devoted and will strengthen their bond by grooming one another. Male saki monkeys are usually more active than females.

They are considered monogamous, but have seldomly 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 occuring (but not exclusively) in Guyana, South America.[8]

But most observations conclude that they travel in small groups of 2 and 3 which usually include the 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.

Locomotion

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White faced sakis vary from many other primates in that they are predominantly leapers, which is how they travel 70 percent of the time. The other 30 percent is spent quadrupedal walking and running (25 percent) and climbing (less than 5 percent).[10]

Diet

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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.[7]

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.[1] [11]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.[11]

Predation

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If a predator is near, alarm calls will be sounded by an initial saki and then continually echoed by others to spread the warning.[11] They will then puff their bodies up and stomp their feet on the ground or trees in an attempt to intimidate the threat. 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 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. According to a study by T.M. Gleason, 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, green anacondas, ocelots, red-tailed boa, and even large mustelids, which are usually threats to the young and elderly.[9]

References

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  1. [ Groves, C.P. (2005). "Order Primates". In Wilson, D.E.; Reeder, D.M. Mammal Species of the World: A Taxonomic and Geographic Reference (3rd ed.). Johns Hopkins University Press. p. 148. ISBN 978-0-8018-8221-0. OCLC 62265494.
  2. [Marsh, L.K.; Mittermeier, R.A.; Veiga, L.M. (2015). "Pithecia pithecia". IUCN Red List of Threatened Species. Version 2015.2. International Union for Conservation of Nature. Retrieved 4 July 2015.
  3. [ Groves, C.P. (2005). "Pithecia pithecia chrysocephala". In Wilson, D.E.; Reeder, D.M. Mammal Species of the World: A Taxonomic and Geographic Reference (3rd ed.). Johns Hopkins University Press. p. 148. ISBN 978-0-8018-8221-0. OCLC 62265494.
  4. [Marsh, L. K. (July 2014). "A Taxonomic Revision of the Saki Monkeys, Pithecia Desmarest, 1804". Neotropical Primates. 21 (1): 1–165. doi:10.1896/044.021.0101.
  5. [Savage, A. et al. (1995). Selected aspects of female white-faced saki (Pithecia pithecia) reproductive biology in captivity. Zoo Biology 14(5):441–452. Retrieved 8 July 2008, from Wiley InterScience Journals database. doi:10.1002/zoo.1430140506.
  6. [Cunningham, E. & Janson, C. Anim Cogn. "Integrating information about location and value of resources by white-faced saki monkeys (Pithecia pithecia)". pp 293-294. (2007) 10: 293. doi:10.1007/s10071-007-0077-4
  7. [ Primatologists, Women. "Variations in group size in white-faced sakis (Pithecia pithecia): evidence for monogamy or seasonal congregations?." pp 96-98. Neotropical primates 9.3 (2001): 96.
  8. [ Gleason, T.M. and Norconk, M.A. (2002) ‘Predation risk and antipredator adaptations in whitefaced sakis, Pithecia pithecia’, in Miller, L.E. (ed.) Eat or be Eaten: Predator Sensitive Foraging Among Primates. Cambridge: Cambridge University Press, pp. 169–184.http://www.personal.kent.edu/~mnorconk/docs/gleason-norconka2002.pdf.
  9. [ Fleagle, J. G. and Meldrum, D. J. (1988), Locomotor behavior and skeletal morphology of two sympatric pitheciine monkeys, Pithecia pithecia and Chiropotes satanas. Am. J. Primatol., 16: 227–249. http://www.personal.kent.edu/~mnorconk/docs/gleason-norconka2002.pdf
  10. http://www.oregonzoo.org/discover/animals/white-faced-saki-monkey
  11. https://www.stlzoo.org/animals/abouttheanimals/mammals/lemursmonkeysapes/whitefacedsaki/
  12. Grubich, N. 2013. "Pithecia pithecia" (On-line), Animal Diversity Web. Accessed December 08, 2016 at http://animaldiversity.org/accounts/Pithecia_pithecia/

Description

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The Alaskan Hare is one of the most largest species of hares. In the summer, Alaskan Hares have a brown fur coat with white under parts. In the winter, they have a white fur coat with black-tipped ears. The Alaskan Hare's ears are fairly short compared to most. Hare's ears play an important role in thermoregulation, and with the Alaskan Hare's ears being small, it prevents heat loss in cold climates. Hares can also carry Tularemia which is a bacterial disease that can be transmitted to pets and humans. It can cause infectious wounds, swollen lymph nodes, and fever or symptoms that feel as if you have the flu. They are trapped more for their fur rather than their meat. Their fur can be and is used to line shoes and robes in Alaska.[2]

Diet

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Alaskan Hares also feed on green plants in the summer, and bark and twigs in the winter.[2]

2. Dfg.webmaster@alaska.gov. "Alaska Hare Species Profile, Alaska Department of Fish and Game." Alaska Hare Species Profile,. Alaska Department of Fish and Game, n.d. Web. 09 Dec. 2016. <http://www.adfg.alaska.gov/index.cfm?adfg=alaskahare.main>.

  1. ^ "Variation on Frugivory: The Diet of Venezuelan White-Faced Sakis". connection.ebscohost.com. Retrieved 2016-11-30.
  2. ^ a b dfg.webmaster@alaska.gov. "Alaska Hare Species Profile, Alaska Department of Fish and Game". www.adfg.alaska.gov. Retrieved 2016-12-09.