Tarsiustarsiers

Diversity

The genus Tarsius is the only genus in the family Tarsiidae. This small nocturnal primate genus consists of 10 tarsier species including; T. dentatus, T. fuscus, T. lariang, T. pelengensis, T. pumilus, T. sangirensis, T. supriatnai, T. tarsier, T. tumpara, and T. wallacei (Groves, 2018). Tarsiers are recognized by their large, beady, reddish-orange eyes and tiny stature. They weigh between 80 and 150 grams (Welman, 2017) and have an average body length of 12 centimeters (Merker, 2008). All species experience sexual dimorphism and females tend to be smaller than males. The fossil record of tarsiers dates to between 34 and 56 million years ago, in the Eocene era (Zijlstra, 2013). (Groves, 2018; Merker and Yustian, 2008; Zijlstra, et al., 2013)

Geographic Range

Tarsiers inhabit tropical forests and islands of Southeast Asia. The island archipelagos of Southeast Asia include Sumatra, Borneo, Sulawesi, the southern Philippines, and smaller neighboring islands. There are 3 clades of living Tarsius species; western tarsiers, Philippine tarsiers, and Sulawesi tarsiers (Driller, 2015). These clades are composed evolutionarily and geographically, as some species are only found on certain islands or in particular regions. Fossils of Eocene and Miocene tarsiers are found in China, Thailand, and southern Pakistan (Zijlstra, 2013). (Driller, et al., 2015; Zijlstra, et al., 2013)

Habitat

Tarsiers strictly inhabit forests of Southeast Asia. They reside in both primary and secondary habitats. These arboreal primates are found in forests that range in density and agriculture from island to island. Tarsiers main mode of locomotion is leaping from tree to tree. Tarsiers, being noctural, sleep during the daylight and predominantly roost in dense vegetation (Merker, 2008). Vegetation includes shrubs, bamboo, palm, dense thickets of grass, bush, thorn scrubs, and secondary habitats on plantations for logging and growing coffee, nutmeg, coconut, or coca crops (Gron, 2010) (MacKinnon, 1980). (Gron, 2010; Merker and Yustian, 2008; Zijlstra, et al., 2013)

Physical Description

Tarsiers are small furry primates with large red eyes, small dentition, and short limbs and hands relative to other primates (Groves, 2010). Tarsier eye size, relative to body size, is the largest of any mammal and directly correlates to their nocturnal behavior (Gillian, et al. 2016). Tarsier dentition indicates an insectivorous diet, but some species will prey on small birds and rodents, crabs, frogs, bats, or snakes (MacKinnon, 1980). Their pelage is mostly grey, with hues of red, yellow, or brown (Gron, 2010). Tarsius species that inhabit different geographic ranges may exhibit differences in coat color, eye size, dentition, limb proportions, and hair length of tails or heels (Gron, 2010). Tarsiers are sexually dimorphic, where females are smaller in size than males (Welman et al, 2017). Tarsiers vary in size, ranging from 80-150 grams (Welman et al, 2017) and 10-15 centimeters long (Merker and Yustian, 2008). Tarsiers possess a unique spinal column that permits the ability to turn their heads almost 360 degrees. Other unique adaptations include the claws on their second and third digits, padded fingers, and long tarsal bones at their heels (Gron, 2010). (Gron, 2010; Groves and Shekelle, 2010; MacKinnon and MacKinnon, 1980; Merker and Yustian, 2008; Welman, et al., 2017)

  • Sexual Dimorphism
  • male larger

Reproduction

Some species of Tarsius remain in lifelong groups of both males and females, while in other species the males and females rarely interact and even occupy different geographical ranges (Van Shaik and Kappeler, 1997). Some tarsier species enact mating rituals of "duetting", or mating calls that entail one party chattering out and another responding with a similar chatter. Some species that live in groups demonstrate alloparental care, where members occasionally look after another member’s young. Other species practice monogamous pair mating, where only parents will interact with their offspring. Mating pairs are territorial, while individuals in social species are often not (MacKinnon, 1980). Tarsier juveniles often have an orange tinge to their coat hair (Shekelle and Nietch, 2008). Juveniles grow to half the size of an adult tarsier in about 3 months, but are still smaller than adults until about 2 years of age (MacKinnon, 1980). (MacKinnon and MacKinnon, 1980; Shekelle and Nietch, 2008; Van Schaik and Kappeler, 1997)

Tarsiers have 2 mating seasons, in 6 month intervals. They exhibit mating calls referred to as "duets" to find and monitor mate ranges. All species designate a spot to roost in dense vegetation, usually either in pairs or groups. Occasionally young males seeking a group or mate will be alone for a period of time. Some species that stay in groups will let males join. Other species form groups that are exclusively male or female, and the two sexes only come into contact to breed. Females give birth to one offspring at a time (MacKinnon, 1980). (MacKinnon and MacKinnon, 1980)

For the first three weeks of an infant tarsier's life, it is common for the mother to carry them in their mouths whenever they move. In pair-bonded species fathers also carry infants in their mouths. While mothers hunt, the infants are often left on a tree branch for intervals of time. In a monogamous pair both parents will visit the infant during this time. In groups other group members might make brief visits to check up on the infant while the mother is away. Once the infant is about a month old it begins hunting on its own, but remains in the group and within visible range. Females often remain in their parental group throughout their life, unless forming monogamous pairs. Males often leave to live alone or join other groups between 1 to 2 years of age (MacKinnon, 1980). (MacKinnon and MacKinnon, 1980)

Lifespan/Longevity

Longevity and lifespan has not yet been established for many species of Tarsius. Any evidence of captive lifespan is not directly applicable to wild tarsier lifespan. The longest reported lifespan in captivity is over 17 years. The oldest individual caught in the wild is estimated at 10 years old. Tarsier behavior changes due to old age between 14 and 16 years of age. Signs of advanced aging may include graying of hair around the face and dental wear (Shekelle and Nietch, 2008). (Shekelle and Nietch, 2008)

Behavior

Tarsiers are nocturnal mammals that awake around sunset and spend the nights foraging for insects, eating, traveling between trees, resting, and socializing. Socialization includes grooming each other, scent marking, vocalizing (including duetting), and playing (Gursky, 1998). Males travel longer distances and occupy a larger area, while females hunt more efficiently and consume more insects (Neri-Arboleda et al, 2002). Tarsiers are both monogamous and polygynous. Some live in pairs, groups of variable size, and some males may live alone. (Gursky-Doyen, 2010). (Gursky, 1998; Gursky-Doyen, 2010; Neri-Arboleda, et al., 2002)

Communication and Perception

Tarsiers communicate through vocalization and scent marking. Vocalizations include high pitched whistles and chattering melodies referred to as duets. High-pitched whistles are varied from simple calls to predator warnings. Some tarsiers have distinct vocalizations to mob, or ward off, a predator (Gursky-Doyen 2010). The duet vocalizations are likely a mating call to lead males to females. Scent marking on trees is used to attract mates and warn off competitors by marking territory (Neri-Arboleda, 2002). (Gursky-Doyen, 2010; Neri-Arboleda, et al., 2002)

Food Habits

Tarsiers consume an exclusively carnivorous diet. Their diet is mostly insectivorous, but some species will prey on small birds and rodents, crabs, frogs, bats, or snakes (MacKinnon, 1980). Vision adaptations allow for hunting at night, through dense areas of forests (Welman et al, 2017). Limb adaptions allow for quick leaping locomotion between trees while capturing prey. They hunt prey on the ground, in the air, and on tree branches and leaves (Gron, 2010). Tarsiers capture methods typically include grabbing with strong, long fingers or leaping onto prey (Gron, 2010). (Gron, 2010; Welman, et al., 2017)

Predation

The primary predators of tarsiers are monitor lizards, civets, snakes, and diverse birds of prey. In the presence of bird predators, individuals vocalize and disperse to hide. When in the presence of a terrestrial predator, such as a snake, individuals “mob” the threat. When mobbing, all individuals respond to a threat with vocalizations as each repeats lunging towards and retreating from the predator (Gursky, 2002). Recent studies suggest predation by domestic animals as habitats grow smaller, and people who capture and sell (Shekelle and Nietch, 2008) or who erroneously consider them pests in farmland (Canete, 2003). (Canete, 2003; Gursky, 2002; Shekelle and Nietch, 2008)

  • Anti-predator Adaptations
  • cryptic
  • Known Predators
    • Snakes
    • Monitor Lizards
    • Civets
    • Birds of Prey

Ecosystem Roles

Tarsier niches are largely as predator and prey. Their presence affects the population size of organisms that they feed on and of those who feed on them. They are host to many different endo- and ectoparasites, including mites and intestinal worms (Shekelle and Nietch, 2008). (Shekelle and Nietch, 2008)

Commensal/Parasitic Species
  • mites (Acari)
  • intestinal worms

Economic Importance for Humans: Positive

Tarsiers draw crowds of eco-tourism, trophy hunters, and animal collectors. Some natives to Southeastern Asia, where tarsiers reside, make a living off of the attraction they draw (Canete, 2003). (Canete, 2003)

Economic Importance for Humans: Negative

Like most primates, some parasites and diseases can be passed from tarsiers to humans. Although some agriculturalists consider them pests, this is a misconception because they do not negatively impact crops or farmland (Canete, 2003). (Canete, 2003)

Conservation Status

Habitat loss and deforestation contributes to a decline in tarsier populations (Merker and Yustian, 2008). Currently, tarsiers reside in many protected areas. T. bancanus, T. dentatus, and T. tarsier are considered vulnerable. Tarsius syrichta is considered near threatened. Tarsius pelengensis and T. sangirensis are considered endangered. Tarsius tumpara is considered critically endangered. Tarsius lariang, T. pumilus, and T. wallacei are listed as data deficient. Tarsiers are protected through international treaties (Shekelle et al, 2018). (Merker and Yustian, 2008; Shekelle, et al., 2018)

  • IUCN Red List [Link]
    Not Evaluated

Other Comments

Four fossil species are known. Specimen are dated from the middle Eocene of China, middle Miocene of Thailand, Oligocene of Egypt, Miocene of Lybia, and Eocene of Myanmar (Zijlstra, 2013). Because of the interest toward dividing the genus into 3, some species are referred to as the attempted revised taxonomic names including the genera Carlito and Cephalopachus . Molecular data and physiological differences noted by Groves and Shekelle suggest this may be true. There may be some cryptic species of Tarsius yet to be discovered (Groves and Shekelle, 2010). (Groves and Shekelle, 2010; Zijlstra, et al., 2013)

Contributors

Sabrina Archuleta (author), Colorado State University, Tanya Dewey (editor), University of Michigan-Ann Arbor.

Glossary

acoustic

uses sound to communicate

agricultural

living in landscapes dominated by human agriculture.

altricial

young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.

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

causes disease in humans

an animal which directly causes disease in humans. For example, diseases caused by infection of filarial nematodes (elephantiasis and river blindness).

chemical

uses smells or other chemicals to communicate

cooperative breeder

helpers provide assistance in raising young that are not their own

crepuscular

active at dawn and dusk

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.

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

ecotourism

humans benefit economically by promoting tourism that focuses on the appreciation of natural areas or animals. Ecotourism implies that there are existing programs that profit from the appreciation of natural areas or animals.

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.

female parental care

parental care is carried out by females

food

A substance that provides both nutrients and energy to a living thing.

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.

male parental care

parental care is carried out by males

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.

polygynandrous

the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.

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

seasonal breeding

breeding is confined to a particular season

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.

References

Brown, R., J. Weghorst, K. Olson, M. Duya, A. Barley, M. Duya, M. Shekelle, I. Neri-Arboleda, J. Esselstyn, N. Dominy, P. Ong, G. Moritz, A. Luczon, M. Diesmos, A. Diesmos, C. Siller. 2014. Conservation Genetics of the Philippine Tarsier: Cryptic Genetic Variation Restructures Conservation Priorities for an Island Archipelago Primate. PLoS One, 9/8: 1. Accessed March 26, 2018 at 10.1371/journal.pone.0104340.

Burrows, A. 2018. Functional Morphology of Mimetic Musculature in Primates: How Social Variables and Body Size Stack up to Phylogeny. The Anatomical Record : Advances in Integrative Anatomy and Evolutionary Biology, 301: 202-215.

Canete, A. 2003. HOW DOES SPECIES ENDANGERMENT BEGIN? TARSIER CONSERVATION, ECO-TOURISM, AND FARMERS IN TWO TOWNS IN THE PROVINCE OF BOHOL, PHILIPPINES. University of San Carlos Publications, 31/3: 182-206. Accessed May 04, 2018 at http://www.jstor.org/stable/29792525.

Catchpole, H., J. Fulton. 1943. The Oestrus Cycle in Tarsius: Observations on a Captive Pair. Journal of Mammalogy, 24: 90-93. Accessed January 05, 2018 at www.jstor.org/stable/1374784.

Driller, C., S. Merker, D. Perwitasari-Farajallah, W. Sinaga, N. Anggraeni, H. Zischler. 2015. Stop and Go – Waves of Tarsier Dispersal Mirror the Genesis of Sulawesi Island. PLoS One, 10/11: 1-20.

Faulkner, S., M. Stevenson, R. Verity, A. Mustari, S. Semple, D. Tosh, S. Le Comber. 2014. Using geographic profiling to locate elusive nocturnal animals: a case study with spectral tarsiers. Journal of Zoology, 0952-8369: 261-268.

Gebo, D., M. Dagosto, X. Ni, C. Beard. 2017. Phalangeal morphology of Shanghuang fossil primates. Journal of Human Evolution, 113: 38-82. Accessed January 05, 2018 at https://doi.org/10.1016/j.jhevol.2017.08.001.

Gron, K. 2010. "Tarsier (Tarsius) Taxonomy, Morphology, & Ecology" (On-line). Primate Factsheets. Accessed March 26, 2018 at http://pin.primate.wisc.edu/factsheets/entry/tarsier.

Groves, C., M. Shekelle. 2010. The Genera and Species of Tarsiidae. International Journal of Primatology, 31/6: 1071-1082. Accessed February 12, 2018 at https://link-springer-com.ezproxy2.library.colostate.edu/article/10.1007/s10764-010-9443-1.

Groves, C. 2018. "Tarsius" (On-line). ITIS Report. Accessed January 29, 2018 at https://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=572805#null.

Gursky-Doyen, S. 2010. Intraspecific Variation in the Mating System of Spectral Tarsiers. International Journal of Primatology, 31: 1161-1173.

Gursky, S. 2002. Determinants of gregariousness in the spectral tarsier(Prosimian: Tarsius spectrum). Journal of Zoology, 256: 401-410.

Gursky, S. 1998. Effects of radio transmitter weight on a small nocturnal primate. American Journal of Primatology, 46/2: 145-155.

Heerschop, S., H. Zischler, S. Merker, D. Perwitasari-Farajallah, C. Driller. 2016. The pioneering role of PRDM9 indel mutations in tarsier evolution. Scientific Reports, 6: 1-11.

Janiak, M., M. Chaney, A. Tosi. 2017. Evolution of acidic mammalian chitinase genes (CHIA) is related to body mass and insectivory in primates. Molecular Biology and Evolution, msx312: 1-10. Accessed January 05, 2018 at https://doi.org/10.1093/molbev/msx312.

Lovegrove, B. 2014. Are Tropical Small Mammals Physiologically Vulnerable to Arrhenius Effects and Climate Change?. Physiological and Biochemical Zoology: Ecological and Evolutionary Approaches, 87: 30-45. Accessed January 05, 2018 at www.jstor.org/stable/10.1086/673313.

MacKinnon, J., K. MacKinnon. 1980. The behavior of wild spectral tarsiers. International Journal of Primatology, 1/4: 361-379.

McNab, B., P. Wright. 1987. Temperature Regulation and Oxygen Consumption in the Philippine Tarsier Tarsius Syrichta. Physiological Zoology, 60: 596-600. Accessed January 05, 2018 at www.jstor.org/stable/30156133.

Menke, P., W. Henke. 2008. The Hyo-Laryngeal Complex of ‘Tarsius Bancanus’ (Mammalia, Primates): a Developmental and Phylogenetic Aspect.. Anthropologischer Anzeiger, 66: 257-272. Accessed January 05, 2018 at www.jstor.org/stable/29542959.

Merker, S., I. Yustian. 2008. Habitat use analysis of Dian’s tarsier (Tarsius dianae) in a mixed-species plantation in Sulawesi, Indonesia. Primates, 2: 161-164. Accessed February 12, 2018 at https://link-springer-com.ezproxy2.library.colostate.edu/article/10.1007/s10329-007-0072-z.

Moritz, G., P. Ong, G. Perry, N. Dominy. 2017. Functional preservation and variation in the cone opsin genes of nocturnal tarsiers. Functional preservation and variation in the cone opsin genes of nocturnal tarsiers, 372: 1-10.

Neri-Arboleda, I., P. Stott, N. Arboleda. 2002. Home ranges, spatial movements and habitat associations ofthe Philippine tarsier (Tarsius syrichta) in Corella, Bohol. Journal of Zoology, 257: 387-402.

Ross, C. 2000. Into the Light: The Origin of Anthropoidea. Annual Review of Anthropology, 29: 147-194. Accessed January 05, 2018 at www.jstor.org/stable/223419.

Schmitz, J., A. Noll, C. Raabe, G. Churakov, R. Voss, M. Kiefmann, T. Rozhdestvensky, J. Brosius, R. Baetsch, H. Clawson, C. Roos, A. Zimin, P. Minx, M. Montague, R. Wilson, W. Warren. 2016. Genome sequence of the basal haplorrhine primate Tarsius syrichta reveals unusual insertions. Nature Communication, 7: 1-11.

Shekelle, M. 2010. Molecular Phylogenetics and Chronometrics of Tarsiidae Based on 12S mtDNA Haplotypes: Evidence for Miocene Origins of Crown Tarsiers and Numerous Species within the Sulawesian Clade. International Journal of Primatology, 31/6: 1083-1106. Accessed February 12, 2018 at https://link-springer-com.ezproxy2.library.colostate.edu/article/10.1007/s10764-010-9457-8.

Shekelle, M., A. Salim, I. Arboleda. 2018. "The IUCN Red List of Threatened Species" (On-line). The IUCN Red List of Threatened Species. Accessed March 04, 2018 at http://www.iucnredlist.org/details/summary/21491/0.

Shekelle, M., A. Nietch. 2008. TARSIER LONGEVITY: DATA FROM A RECAPTURE IN THE WILD AND FROM CAPTIVE ANIMALS. Primates of The Oriental Night, 1: 85-90.

Straus, W. 1931. The Form of the Tracheal Cartilages of Primates, with Remarks on the Supposed Taxonomic Importance.”. Journal of Mammalogy, 12: 281-285. Accessed January 05, 2018 at www.jstor.org/stable/1373878.

Van Schaik, C., P. Kappeler. 1997. Infanticide Risk and the Evolution of Male-Female Association in Primates. Proceedings: Biological Sciences, 264/1388: 1687-1694. Accessed February 19, 2018 at www.jstor.org/stable/50779.

Welman, S., A. Tuen, B. Lovegrove. 2017. Searching for the Haplorrhine Heterotherm: Field and Laboratory Data of Free-Ranging Tarsiers. Frontiers in Physiology, 8/745: 1-13.

Wiesemuller, B., R. Hartmut. 1999. New World Monkeys — A Phylogenetic Study. Zeitschrift Für Morphologie Und Anthropologie, 82: 115-157. Accessed January 05, 2018 at www.jstor.org/stable/25757548.

Zijlstra, J., L. Flynn, W. Wessels. 2013. The westernmost tarsier: A new genus and species from the Miocene of Pakistan. Journal of Human Evolution, 65: 544-550.