The pygmy tarsier (''Tarsius pumilus''), also known as the mountain tarsier or the lesser spectral tarsier, is a

nocturnal Nocturnality is a ethology, behavior in some non-human animals characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal", versus diurnality, diurnal meaning the opposite. Nocturnal creatur ...

primate Primates is an order (biology), order of mammals, which is further divided into the Strepsirrhini, strepsirrhines, which include lemurs, galagos, and Lorisidae, lorisids; and the Haplorhini, haplorhines, which include Tarsiiformes, tarsiers a ...

found in central

Sulawesi Sulawesi ( ), also known as Celebes ( ), is an island in Indonesia. One of the four Greater Sunda Islands, and the List of islands by area, world's 11th-largest island, it is situated east of Borneo, west of the Maluku Islands, and south of Min ...

Indonesia Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania, between the Indian Ocean, Indian and Pacific Ocean, Pacific oceans. Comprising over List of islands of Indonesia, 17,000 islands, including Sumatra, ...

, in an area with lower vegetative

species diversity Species diversity is the number of different species that are represented in a given community (a dataset). The effective number of species refers to the number of equally abundant species needed to obtain the same mean proportional species abundan ...

than the lowland

tropical forests Tropical forests are forested ecoregions with tropical climates – that is, land areas approximately bounded by the tropics of Cancer and Capricorn, but possibly affected by other factors such as prevailing winds. Some tropical forest types ...

. The pygmy tarsier was believed to have become extinct in the early 20th century. Then, in 2000, Indonesian scientists accidentally killed one while trapping rats. The first pygmy tarsiers seen alive since the 1920s were found by a research team led by Dr. Sharon Gursky and Ph.D. student Nanda Grow from

Texas A&M University Texas A&M University (Texas A&M, A&M, TA&M, or TAMU) is a public university, public, Land-grant university, land-grant, research university in College Station, Texas, United States. It was founded in 1876 and became the flagship institution of ...

Mount Rore Katimbo Mount is often used as part of the name of specific mountains, e.g. Mount Everest. Mount or Mounts may also refer to: Places * Mount, Cornwall, a village in Warleggan parish, England * Mount, Perranzabuloe, a hamlet in Perranzabuloe parish, C ...

Lore Lindu National Park Lore Lindu National Park is a protected area of forest on the Indonesian island of Sulawesi, in the province of Central Sulawesi. The List of national parks of Indonesia, Indonesian national park is 2,180 km2 covering both lowland and mont ...

in August 2008. The two males and single female (a fourth escaped) were captured using

net NET may refer to: Broadcast media United States * National Educational Television, the predecessor of the Public Broadcasting Service (PBS) in the United States * National Empowerment Television, a politically conservative cable TV network ...

s, and were radio collared to track their movements. As the first live pygmy tarsiers seen in 80-plus years, these captures dispelled the belief among some

primatologists Primatology is the scientific study of non-human primates. It is a diverse discipline at the boundary between mammalogy and anthropology, and researchers can be found in academic departments of anatomy, anthropology, biology, medicine, psycholo ...

that the species was extinct.

Description

The pygmy tarsier has a head-body length of , and weighs less than , which makes it smaller and lighter than other

tarsier Tarsiers ( ) are haplorhine primates of the family Tarsiidae, which is the lone extant family within the infraorder Tarsiiformes. Although the group was prehistorically more globally widespread, all of the existing species are restricted to M ...

species. Likewise, its ears are also smaller than those of the rest of genus ''

Tarsius ''Tarsius'' is a genus of tarsiers, small primates native to islands of Maritime Southeast Asia, with almost all of its species found on Sulawesi Island. Until 2010, all tarsier species were typically assigned to this genus, but a revision of t ...

''. Its fur is tan or buff with predominant grey or brownish red coloring. Its tail is heavily haired and ranges from , and functions in balance when leaping. The pygmy tarsier has nails on all five digits of each hand and on two digits of each foot. The claw-like nails aid in its grasping strength and are also used as an aid in its need for vertical support for feeding and movement. Pygmy tarsiers exhibit low

sexual dimorphism Sexual dimorphism is the condition where sexes of the same species exhibit different Morphology (biology), morphological characteristics, including characteristics not directly involved in reproduction. The condition occurs in most dioecy, di ...

, so both sexes are similar in size and appearance. The most noticeable feature of the pygmy tarsier are its large eyes, which are about in diameter. Unlike other nocturnal species, tarsiers lack a

tapetum lucidum The ; ; : tapeta lucida) is a layer of tissue in the eye of many vertebrates and some other animals. Lying immediately behind the retina, it is a retroreflector. It Reflection (physics), reflects visible light back through the retina, increas ...

due to the diurnal evolutionary history of primates. To make up for this, tarsiers have evolved their large eyes to maximize available light. Tarsiers eyes cannot move in their sockets, but their necks have the ability to turn their heads almost 360 degrees.

Habitat

The pygmy tarsier is

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

to the mossy cloud forests of central Sulawesi, Indonesia and found at altitudes of . The canopy of the mountain forests are low in height and undergrowth is much denser than the lowland forests. The plant diversity is low and covered in thick mosses, resulting in decreased habitat productivity. Pygmy Tarsiers handle this challenging habitat by living at the edge of forests where prey is more abundant.

Diet

Pygmy tarsiers are

insectivorous A robber fly eating a hoverfly An insectivore is a carnivorous animal or plant which eats insects. An alternative term is entomophage, which can also refer to the human practice of eating insects. The first vertebrate insectivores we ...

, feeding primarily on arthropods. Due to their arboreal lifestyle, their diet consists of airborne insects found in the forest canopy such as moths, grasshoppers, and katydids.

Behavior and ecology

The pygmy tarsier is found in stable bonded pairs, remaining together for up to 15 months. This stable pair bond is usually monogamous. The species has two breeding seasons, one at the beginning of the rainy season and the other at the end, separated by about 6 months.

Gestation Gestation is the period of development during the carrying of an embryo, and later fetus, inside viviparous animals (the embryo develops within the parent). It is typical for mammals, but also occurs for some non-mammals. Mammals during pregn ...

lasts 178 days on average, and births occur in May and from November to December. Infants are quite

precocial Precocial species in birds and mammals are those in which the young are relatively mature and mobile from the moment of birth or hatching. They are normally nidifugous, meaning that they leave the nest shortly after birth or hatching. Altricial ...

, and develop quickly, similar to other juveniles in the genus. The offspring begin capturing their own prey around 42 days of age, and travel in groups after only 23 days. Young females remain with parents until adulthood, while young males leave the natal group as juveniles. The pygmy tarsier is

crepuscular In zoology, a crepuscular animal is one that is active primarily during the twilight period, being matutinal (active during dawn), vespertine (biology), vespertine/vespertinal (active during dusk), or both. This is distinguished from diurnalit ...

, and is mainly

arboreal Arboreal locomotion is the locomotion of animals in trees. In habitats in which trees are present, animals have evolved to move in them. Some animals may scale trees only occasionally (scansorial), but others are exclusively arboreal. The hab ...

. It spends most of the daylight hours sleeping on vertical branches in the canopy. ''T. pumilus'' is not a nest builder. Unlike other tarsier species, it does not use scent glands to mark territorial boundaries. Also tactile

communication Communication is commonly defined as the transmission of information. Its precise definition is disputed and there are disagreements about whether Intention, unintentional or failed transmissions are included and whether communication not onl ...

and interaction is important with the pygmy tarsier, as in other tarsier species. Some species of tarsier have recently been found to communicate at ultrasonic frequencies of around 70 kHz on the islands of

Bohol Bohol (), officially the Province of Bohol (; ), is an island province of the Philippines located in the Central Visayas Regions of the Philippines, region, consisting of the island itself and 75 minor surrounding islands. It is home to Bohola ...

and

Leyte Leyte ( ) is an island in the Visayas group of islands in the Philippines. It is eighth-largest and sixth-most populous island in the Philippines, with a total population of 2,626,970 as of 2020 census. Since the accessibility of land has been ...

. The ultrasonic range of their communication is well beyond what may be detected by the human ear and is a distinct advantage to keeping their communication species-specific.

References

External links

Photos of living 'gremlin' discovered in Indonesia
{{Taxonbar, from=Q244208

pygmy tarsier The pygmy tarsier (''Tarsius pumilus''), also known as the mountain tarsier or the lesser spectral tarsier, is a nocturnal primate found in central Sulawesi, Indonesia, in an area with lower vegetative species diversity than the lowland tropical ...

Endemic fauna of Indonesia Mammals of Sulawesi Primates of Indonesia