Tarsius syrichtaPhilippine tarsier

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Geographic Range

Tarsius syrichta is found in the rainforests of the Philippines. This species is most commonly found on Samar, Leyte, Bohol, and Mindanao.

Habitat

Philippine tarsiers are found in areas of tall grasses, bushes, bamboo shoots, and small trees in tropical rainforests. They enjoy the canopy of the jungle, leaping from limb to limb. Tarsiers usually do not move using four limbs; rather, they have developed excellent leaping skills.

Physical Description

Tarsius syrichta is a small brownish-grayish mammal. Their colors vary depending upon the region of the Philippines that they inhabit. Some have reddish-brown hair.

Body size is approximately 85 to 160 mm, with weights between 80 and 165 g. They are about the size of a young child's hand. They have a 25 cm long tail that is tufted at the end.

Tarsiers have large ears, resembling a bat, and round faces. The area surrounding their eyes is usually darker than their body, with no white marks anywhere on the face. The eyes are huge, and their vision is acute. In proportion to their body, their eyes are the largest among mammals. The tarsier's great hearing, coupled with their amazing sense of sight, make them highly successful nocturnal hunters. Their heads can rotate 180 degrees.

The legs and arms of these tarsiers are long and slender. Some of their digits have flattened nails and some have claws which are used for grooming. They have pads on their fingers and toes to help them cling to branches. Their legs are strong, and they are capable of jumping distances up to twenty feet.

Tarsiers differ from other prosimians in several characters. These include two grooming claws on each foot, lack of a toothcomb formed by the lower canines and incisors, and a diploid number of eighty chromosomes. Tarsiers are also less vocal than many other primates.

  • Sexual Dimorphism
  • sexes alike
  • Range mass
    85 to 165 g
    3.00 to 5.81 oz
  • Range length
    80 to 160 mm
    3.15 to 6.30 in
  • Average basal metabolic rate
    0.43 W
    AnAge

Reproduction

These animals are usually seen in male-female pairs, indicating that like other tarsiers, they probably mate monogamously.

Breeding occurs throughout the year. Tarsier females bear a single young. The gestation period lasts six months. Recent research shows that the breeding season of tarsiers is defined by the availability of insects.

Young are able to capture prey by about 45 days of age, and are thought to be weaned around that time.

  • Breeding interval
    Most tarsiers breed twice per year.
  • Breeding season
    Breeding occurs throughout the year.
  • Average number of offspring
    1
  • Average number of offspring
    1
    AnAge
  • Average gestation period
    6 months
  • Average gestation period
    179 days
    AnAge
  • Average weaning age
    45 days

The females have multiple pairs of nipples; however, only the pectoral are used. Offspring are born well-furred and with eyes open. They are able to move about after only two days. Infants are carried by means of their mother's mouth or on her belly. No nest is built. The young tarsiers can climb after two days and jump after four. Normal locomotor patterns ensue at approximately nineteen days. Juveniles tend to be more uniformly colored than adults.

Females provide the bulk of parental care. The role of the male in rearing the young has not been documented.

  • Parental Investment
  • precocial
  • pre-fertilization
    • provisioning
    • protecting
      • female
  • pre-hatching/birth
    • provisioning
      • female
    • protecting
      • female
  • pre-weaning/fledging
    • provisioning
      • female
    • protecting
      • female
  • pre-independence
    • provisioning
      • female
    • protecting
      • female

Lifespan/Longevity

One T. syrichta is reported to have lived 13.5 years in captivity. It is likely that wild animals do not live as long as their captive counterparts.

Behavior

This species is largely social, but form only male female pairs. They occasionally associate in small groups of generally no more than four animals. They show little fear of other animals, especially humans, unless quick movement is made. When in danger, T. syrichta lets out a high pitched squeak.

Tarsiers are arboreal and nocturnal. They spend the day hiding in dense vegetation and sleeping in trees. At night they emerge to move about and hunt for prey.

Home Range

Tarsiers appear to have home ranges of 1 to 2 hectares.

Communication and Perception

Tarsiers use varied means of communication. Although less vocal than many primate species, these animals use calls which are often associated with territorial maintenance and male-female spacing. In addition, they use scent marks from urine and glandular secretions to delineate their territories. Tactile communication plays some role between mates and between mothers and their offspring. The role of visual communication has not been established for this species, but because they have very keen eyesight, it is likely that body postures and other visual signals are used.

Food Habits

Philippine tarsiers are primatily insectivorous. They eat insects, spiders, lizards, and small vertebrate animals such as birds. Upon seizing its prey, a tarsier carries it in its mouth and using both hands.

  • Animal Foods
  • birds
  • reptiles
  • insects
  • terrestrial non-insect arthropods

Predation

Predation upon these animals has not been widely reported. However, because of their nocturnal and arboreal habits, they are most likely to fall prey to owls, or to small carnivores which can encounter them in their canopy homes.

Ecosystem Roles

As predators, these small primates may help to structure insect communities. To the extent that they are preyed upon by other animals, they may impact predator populations.

Economic Importance for Humans: Positive

Tarsiers are sometimes kept as pets, although their survival in captivity is erratic due to their need for live insects upon which to feed. Scientists are interested in these animals because of their unique taxonomic position, and study of tarsiers may aid human economies.

  • Positive Impacts
  • pet trade
  • research and education

Economic Importance for Humans: Negative

There is no known negative impact of these animals on humans, so long as the tarsiers are in their native environment. However, when kept as pets, there is a possibility that they may spread worms and other parasites to their human owners.

Conservation Status

The current condition of T. syrichta is threatened and endangered. Captive breeding efforts have been started but to date all have been unsuccessful. Tarsiers have suffered greatly from hunters and trappers who shake the animals out of their trees or chop down the branches of the trees in which they live. They have also become popular in the pet industry, especially in Mexico. However, tarsiers rarely live long in captivity. It has been reported that they are so traumatized by captivity that they beat their heads against their cages, eventually killing themselves. Philippine tarsiers are also significantly affected by the increased rate of deforestation in their native habitat.

Other Comments

Because this species is only found in a small area of the world it is crucial that we conserve its environment. The destruction of natural resources in the Philippines continues to affect its inhabitants such as tarsiers. The indigenous land animals of this part of the world are quickly being depleted. Tarsiers were named because of the two greatly elongated bones on their feet. These extra bones give tarsiers added leverage for jumping. Even though they are rat sized, tarsiers can jump four to six feet in a single jump.

Contributors

Nancy Shefferly (editor), Animal Diversity Web.

Carissa Kubicek (author), University of Michigan-Ann Arbor.

Glossary

acoustic

uses sound to communicate

arboreal

Referring to an animal that lives in trees; tree-climbing.

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.

carnivore

an animal that mainly eats meat

chemical

uses smells or other chemicals to communicate

crepuscular

active at dawn and dusk

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.

fertilization

union of egg and spermatozoan

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

insectivore

An animal that eats mainly insects or spiders.

island endemic

animals that live only on an island or set of islands.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

monogamous

Having one mate at a time.

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

nocturnal

active during the night

oriental

found in the oriental region of the world. In other words, India and southeast Asia.

World Map

pet trade

the business of buying and selling animals for people to keep in their homes as pets.

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.

scent marks

communicates by producing scents from special gland(s) and placing them on a surface whether others can smell or taste them

scrub forest

scrub forests develop in areas that experience dry seasons.

sedentary

remains in the same area

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

social

associates with others of its species; forms social groups.

solitary

lives alone

tactile

uses touch to communicate

terrestrial

Living on the ground.

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

tropical

the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.

visual

uses sight to communicate

viviparous

reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

year-round breeding

breeding takes place throughout the year

young precocial

young are relatively well-developed when born

References

Alterman, L. and Doyle, Gerald A. Creatures of the Dark: The Nocturnal Prosimians. Plenum Press, New York. 1995.

Doyle, G.A. and Martin, R.D. The Study of Prosimian Behavior. Academic Press, New York. 1979.

Eimerl, Sarel and DeVore, Irven. The Primates. Time Incorporated, New York. 1965.

Hill, Osman W.C. Primates: Comparative Anatomy and Taxonomy. Edinburgh Press, London. 1955.

"Tarsier." Collier's Encyclopedia. 1996.

"Tarsier." Encyclopedia Americana. 1996.

"Tarsier." World Book Encyclopedia. 1996.

http://www.haribon.org.ph/wildlife/tarsier.htm

http://www.snowcrest.net/goehring/a2/primates/tarsier.htm

http://www.haribon.org.ph/forestry.htm

Nowak, R. 1999. Walker's Mammals of the World, Sixth Edition. Baltimore and London: The Johns Hopkins University Press.