Tarsier, The Tiny Philippine Primate Threatened by Tourism

A very peculiar small animal you'll find indigenous in the Philippines is the Philippine tarsier, or scientifically known as Tarsius syrichta. In fact it is one of the smallest known primates, no larger than an adult men's hand. It lives on a diet of insects and mostly active at night. Folk traditions sometimes has it that tarsiers eat charcoal, but actually they retrieve the insects from (sometimes burned) wood. It can be found in the islands of Samar, Leyte, Bohol, and Mindanao.

In their few numbers left, the tarsier might not survive if no action is taken. Although it is a protected species, and the practice of catching them and then selling them as stuffed tarsiers to tourists has stopped, the species is still threatened by the destruction of his natural forest habitat. Many years of both legal and illegal logging and slash-and-burn agriculture have greatly reduced these forests, and reduced the tarsier population to a dangerously small size. The Philippine tarsier can soon be added to the list of extinct species if no action is taken now.

The Philippine tarsier has a gray fur and a nearly naked tail. The middle finger is elongated. Head and body length are around 118-149 mm; It weighs 113-142 grams. Males are larger than females.

The eyes of the tarsier are enormous in comparison with his body size. In volume, the capacity of the bony eye orbits, or eye sockets, is larger than that of the brain case, and also larger than its stomach. Their eye sockets have post-orbital closure rather than the postorbital bar of the prosimians. This feature keeps the eyeballs from being pressed against by the powerful temporal muscles to their sides.

Generally naked except for a tuft of hair at its end, the tarsier has a relatively very long tail (232 mm). The underside has dermal ridges like those found on human hands and feet. Its tail is used for balancing like a tripod; they prefer an erect posture at all times.

The tarsier has a joint between its skull base and spine like an owl, to allow head movement of a 180-degree arc. Its upper lip lacks a cleft yet, but still has muscles, so that it can make facial expressions. The adult brain weighs about 4 grams.

Enabling them to catch their prey easier, Tarsiers have sharp teeth. Unique among primates, tarsiers have only two, rather than four, incisors in their lower jaw. Their dental formula is 2.1.3.3 1.1.3.3 x 2 = 34.

The name "tarsier" or "tarsius" is derived from the animal's very long ankle bones. The tibia and fibula of the tarsiers, acting as a shock absorber are fused in their lower portions. This is considered a primitive trait, which can normally be seen in quadrupeds. The lower limbs are twice the length of its trunk. These enable the tarsier to leap about three meters from tree to tree. Its movements are similar to that of a frog.

While they also have some characteristics peculiar to themselves, Tarsiers share some characteristics with both the prosimians and the anthropoids. Taxonomists have classified them as intermediate between both groups and have assigned them to their own infraorder, which contains just one living genus: Tarsius. Fossil records of this genus are found, dating back to the Eocene epoch, from 54 to 36 million years ago.
Like many prosimians, they are nocturnal and have grooming claws and bicornuate uterus.

Like anthropoids, they do not have a tapetum (a reflective layer in their eyes).

In tarsiers, the internal structures of the nose and ears and the blood supply to the brain and to a developing fetus are more like those of monkeys than of lorises. The monthly sexual swellings of female tarsiers are also similar to those in anthropoids.

We could often see a slogan "The world's smallest monkey". However, it is not a monkey. The truth is, its classification is somewhat problematic. Some consider tarsiers to be a taxonomic suborder among the primates by some scientists. While, because they are closely related to lemurs, lorises and bushbabies, others classify them with the prosimians to which these animals belong. Monkeys and apes belong to the suborder of anthropoids. The complete taxonomic classification of tarsier thus is:

Class Mammalia
Order Primates
Suborder Prosimii/Haplorrhini
Infraorder Tarsiiformes
Superfamily Tarsioidea

There were three very similar species have been described In the Philippines. It is very well possible that these species are actually a single species, developed into three races due to the physical separation on the various islands.

Species         Location
T. philippensis Samar and Leyte
T. fraterculus Bohol
T. carbonarius Mindanao

A number of relatives of the Philippine tarsier can be found outside the Philippines, among them the Bornean tarsier (Tarsius bancanus) of Borneo and Sumatra, the spectral tarsier (Tarsius spectrum), the lesser spectral tarsier or pygmy tarsier (Tarsius pumilus), and Dian's tarsier (Tarsius dianae) of Sulawesi, Indonesia. The pygmy tarsier, by the way, is considerably smaller than the Philippine tarsier, while the pygmy mouse lemur, found only in Madagascar, is now being recognized as the smallest primate in the world.

Through the description given to J. Petiver by the missionary J.G. Camel of an animal said to have come from the Philippines (Hill, 1955), the tarsier was first introduced to Western biologists. Petiver published Camel's description in 1705 and named the animal Cercopithecus luzonis minimus which was the basis for Linnaeus' (1758) Simia syrichta and eventually Tarsius syrichta. Among the locals here in the Philippines, the tarsier is known as "mamag", "mago", "magau", "maomag", "malmag" and "magatilok-iok".

Dating back to the early Eocene period, the species is believed to be about 45 million years old and probably one of the oldest land species continuously existing in the Philippines.

Currently, although it is not yet categorized as vulnerable, endangered, or critically endangered, the Philippine tarsier is categorized as a "lower risk, conservation dependent" species, which means that, it could qualify for one of those categories within five years if the present protection programs are stopped.

Let’s try to have our share people. Let’s not let these primates be only seen in books by the next generation. Tarsiers are of our own share in nature, God have given us the responsibility to take care of them, let’s prove our worth…

Cheerio!