Siau Island tarsier
The Siau Island tarsier is a species of tarsier from the tiny volcanic island of Siau in Indonesia. The T. tumpara species is one of 14 species and 7 subspecies in the tarsier family called "Tarsiidae". They belong to the Haplorrhini suborder, known as the "dry-nosed" primates. The tarsier's eyes are so big that they do not move in its socket and they are almost as big as its brain. Locally in the Siau dialect of Sangir language, the tarsiers are called Tumpara. The name differs from the Sangihe dialect which called tarsiers, Senggasi or Higo, these names are used for the Sangihe tarsier instead.
Characteristics
Anatomy and physical appearance
The main characteristics of the tumpara tarsiers include having a white ventral fur, lacking the distinctive golden dorsal fur of the Tarsius sangirensis, and having a larger skull compared to its other relatives. Another way to distinguish the T. tumpara from other tarsier species such as T. sangirensis and T. dianae is its distinctive duet note in the different sexes. The Siau Island tarsier is a very small species which measures around 4 to 6 inches in body length. Their long tails can add another 8 inches to their total length. They weigh between 100 and 150 grams, which makes them very quiet when they leap on dense vines or branches.Eyes
The Siau Island tarsier has very big eyes that do not move, and have very big irises that range in shades of gold and brown. The size of its eyes helps the species with nocturnal vision. They have foveal vision, which helps them to see things more sharply. However, they lack a tapetum.Agility
Siau Island tarsiers are an arboreal species, which means they spend most of their time in trees, and therefore are very agile and excellent at jumping and climbing. They can jump up to 10 ft high, have a neck that turns 180 degrees, and have good hearing. They also have long thin fingers which helps them to grab things such as when they are capturing prey. The T. tumpara's main method of hunting consists of sitting quietly on a branch and waiting for a prey to arrive to attack it.Reproduction
Siau Island tarsiers can reach sexual maturity at two years old, this means that they carry and give birth to an offspring. Pregnancy lasts around six months and the mother gives birth to a single offspring.Nutrition
They are a carnivorous species that feed on small animals such as frogs, lizards and small birds, but mostly eat insects like spiders. They have a very wide mouth, strong jaw and sharp teeth which help them feed off small animals.Geography
Tarsiers are found in Southeast Asia, though the T. tumpara is endemic to Siau Island, Indonesia. This species was located geographically using GIS and geographic profiling and they have found that they live in a small range of, with an even smaller occupancy range of approximately. The tumpara tarsier species has a population of approximately 1,358–12,470 and is declining due to the many threats they face.Habitat
The tarsier species are nocturnal and can be found sleeping in tree holes during the day, especially those of fig trees, depending on what forest they are in. They can usually be found entering their trees to go sleep between 5:00 AM and 6:00 AM. The members of each group sleep individually in their own trees to avoid a predator attack on the entire family.Taxonomy
Its existence as a distinct taxon was predicted by the hybrid biogeographic hypothesis for Sulawesi. The rationale was that a geographic discontinuity existed between the northern tip of Sulawesi, and the population of tarsiers on Sangihe Island, approximately to the north. In between, lay very deep oceans and three island clusters, Biaro, Tagulandang/Ruang, and Siau. Like Sangihe Island, itself, each of these three island clusters are a part of the Sangihe Island volcanic arc. Volcanic arcs, like the Galapagos and Hawaiian Island chains, feature islands that erupt from the ocean floor. In such circumstances, islands form independently, are colonized independently, and remain geographically isolated. These characteristics lead to high levels of endemism. The presence of tarsiers on the most distant island group in the Sangihe volcanic arc, led to curiosity about the presence of tarsiers on the other islands in the chain. Each of the three island clusters mentioned above were surveyed for the presence of tarsiers in 2004 and 2005, but tarsiers were only observed on Siau.It was furthermore elaborated upon that the original description of T. sangirensis included mention of a specimen from Siau in the Dresden Museum. Thus it was argued for further investigations of the Siau tarsier to see if it was taxonomically separable from T. sangirensis.