The Jatna’s tarsier (''Tarsius supriatnai''), also known locally as the mimito, is a species of tarsier endemic to the northern Sulawesi,

Indonesia Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania between the Indian and Pacific oceans. It consists of over 17,000 islands, including Sumatra, Java, Sulawesi, and parts of Borneo and New Guine ...

. Previously classified together with the

Spectral tarsier The spectral tarsier (''Tarsius spectrum'', also called ''Tarsius tarsier'') is a species of tarsier found on the island of Selayar in Indonesia. It is apparently less specialized than the Philippine tarsier or Horsfield's tarsier; for example, ...

, this species was reclassified and elevated as a separate species in 2017 due to their distinct and separate acoustic duet calls between males and females.

Taxonomy and etymology

Taxonomic history, discovery, and classification

Following the taxonomic revision of the Tarsiidae primate family in 2010 by the primatologists Colin Groves and Myron Shekelle, all tarsiers found in northern Sulawesi were initially classified under the taxon

(''Tarsius spectrum''). However, subsequent studies conducted in 2017 by a team of researchers led by Myron Shekelle in the Nantu Wildlife Reserve in

Gorontalo Gorontalo ( Gorontaloan: ''Hulontalo'') is a province of Indonesia on the island of Sulawesi. Located on the Minahasa Peninsula, Gorontalo was formerly part of the province of North Sulawesi until its inauguration as a separate province on 5 D ...

, Sulawesi later described a local population of spectral tarsiers found in the area with a distinct acoustic duet call between males and females. This population was then later reclassified and elevated as a separate species under the genus ''

Tarsius ''Tarsius'' is a genus of tarsiers, small primates native to islands of Southeast Asia. Until 2010, all tarsier species were typically assigned to this genus, but a revision of the family Tarsiidae restored the generic status of ''Cephalopach ...

''.

Etymology

The species was named Jatna's tarsier (''Tarsuis supriatnai'') in honour of Dr. Jatna Supriatnai, an Indonesian conservationist who has dedicated much of his professional life contributing to biodiversity and environmental conservation works in Indonesia, particularly on tarsiers.

Ecology

Morphology

Aside from the common basal characteristics shared amongst all tarsier species (disproportionately enlarged eyes and ears, elongated tarsal bones, and the ability to rotate their heads 180 degrees in both directions), Jatna's tarsiers possess a very similar morphology to Gursky's spectral tarsiers, except with a generally larger bare spot at the base of its ear, a less shortened hind foot, a substantially longer tail, and longer middle finger. While surveys of wild populations of Jatna's tarsier indicate that body weight and tail lengths are generally within the range of other tarsier species, body weight dimorphism between males and females may be greater than that of other tarsier species. Males weigh around 135g while females weight around 104-114g, while male tail lengths measure around 246mm and female tail lengths measure around 232-243mm.

Distribution, range, and habitat

The species is endemic to the island of Sulawesi, Indonesia, specifically in the northern parts of the island stretching westwards from the isthmus of

to Sejoli and possibly Ogatemuku. It borders with the

Wallace's tarsier Wallace's tarsier, ''Tarsius wallacei'', is a species of Sulawesi tarsier (all tarsiers from the genus tarsius are from Sulawesi and its surrounding islands). It is found in the forests of what is referred to geologically as the neck of Sula ...

to the west, and the Gursky's spectral tarsier to the east. In the wild, it inhabits tropical rainforests, preferring to nest in dense clusters of vegetation, such as on palm and bamboo trees from the Arecaceae and Poaceae plant families respectively. Common species of nesting trees include the

Bambusa vulgaris ''Bambusa vulgaris'', common bamboo, is an open-clump type bamboo species. It is native to Indochina and to the province of Yunnan in southern China, but it has been widely cultivated in many other places and has become naturalized in several r ...

, Schizostachyum lima,

Calamus zollingeri Calamus may refer to: Botany and zoology * ''Calamus'' (fish), a genus of fish in the family Sparidae * ''Calamus'' (palm), a genus of rattan palms * Calamus, the hollow shaft of a feather, also known as the quill * ''Acorus calamus'', the swe ...

, and

Salacca Zalacca Salak (''Salacca zalacca'') is a species of palm tree (family Arecaceae) native to Java and Sumatra in Indonesia. It is cultivated in other regions of Indonesia as a food crop, and reportedly naturalized in Bali, Lombok, Timor, Maluku, and Sul ...

, while they have also been observed to nest on larger trees like

Ficus virens ''Ficus virens'' is a plant of the genus ''Ficus'' found in Pakistan, India, southeast Asia, through Malaysia and into Northern Australia. Its common name is white fig; it is locally known as ''pilkhan'' and in the Kunwinjku language it is calle ...

Diet

Jatna's tarsiers are fully carnivorous, feeding mostly on insects like moths and crickets, and small vertebrates like lizards and frogs.

Duet calls

Jatna's tarsiers mostly live in monogamous pairs, and as nocturnal creatures, they perform territorial duet calls near dawn before returning to their nesting sites. These usually consist of a 2 to 5 note female phrase accompanied by male calls. They have been found to be significantly distinct from other similar species of tarsiers found within the region, with female notes being flatter and less modulated than other populations of tarsiers found further east around

Manado Manado () is the capital city of the Indonesian province of North Sulawesi. It is the second largest city in Sulawesi after Makassar, with the 2020 Census giving a population of 451,916 distributed over a land area of 162.53 km2.Badan Pusa ...

Conservation and status

Status

As of the latest assessments in 2020, Jatna's tarsiers have been classified as Vulnerable on the IUCN Red List of Threatened Species, with a decreasing population in the wild.

Habitat threats and adaptation

Threats to Jatna's tarsiers' habitats stem from the deforestation and degradation of their tropical rainforest habitats for logging, conversion to agricultural and plantation lands, as well as human settlement purposes, with estimates ranging 12% of its forest habitat lost between 2000 and 2017. However, studies have shown that the species are able to survive and adapt to a certain degree of habitat degradation and conversion, and discriminate between different types of cultivation. For instance, Jatna's tarsiers have been found inhabiting cocoa plantations, nesting among bamboo and rattan tree clusters or secondary forest fragments surrounding the plantation and making use of cocoa trees to support their locomotion. Nevertheless, population densities in such cocoa plantations are still significantly lower than population densities in untouched secondary forest, and hence cannot ascertain that they will be able to reproduce sufficiently in order to persist in cultivated areas.

References

{{Taxonbar, from=Q29865347 Jatna's tarsier Endemic fauna of Indonesia Mammals of Sulawesi Primates of Indonesia Jatna's tarsier Taxa named by Colin Groves Taxa named by Russell Mittermeier