Philippine Tarsier

The Philippine tarsier is the sole living member of the genus Carlito, named after the conservationist Carlito Pizarras. One can easily distinguished by them their disproportionately huge eyes and an exceptionally long, and narrow tail, set against their small body.

They belong to an intermediate family between the lemur and the monkey but are more closely related to the latter than the former since they have a dry nose like them.

Description

Length: 3.35 to 6.30 in (8.5 to 16 cm)

Weight: 2.8–5.6 oz (80–160 g)

Eyes: They have immovable eyes, fixed in their skull. The Philippine tarsier has the largest eye-to-body ratio among all mammals, with their eyes being larger than their brain.

Body and Coloration: They have thin, rough fur. Their ears are large and membranous and can be seen moving in all directions. The narrow tail is bald and twice the length of their entire body except for a tuft of hair at the end. Its elongated ankle bone or a “tarsus” accounts for its name.

The Philippine tarsier coloration vary from gray to dark brown.

Range and Distribution

As its name suggests, this primate resides in the Philippines, most notably in the islands of Bohol, Leyte, Mindanao, and Samar. Their range also includes Basilan Island, Dinagat Island, Maripipi Island, and Siargao Island.

Habitat

They live in rainforests at 2,460 ft (750 m), favoring bamboo shoots, bushes, grasses, and small trees. Some tarsiers can be seen in edge habitats and secondary forests. However, their population density is lower in these disturbed habitats.

Diet

Primarily insectivorous, these tarsiers feed on live insects such as ants, beetles, butterflies, crickets, grasshoppers, locusts, moths, and termites. They even thrive on spiders, bats, and small birds and mammals.

Lifespan

The Philippine tarsier lives for 24 years in the wild.

Behavior

• They are shy, and mostly lead a secluded life. These tarsiers occasionally associate in small groups of four, that only comprise of male-female pairs though.
• They are nocturnal, spending the day hiding in dense vegetation and sleeping in trees, and emerging at night to hunt.
• Philippine tarsiers are fearless, not afraid of anything except sudden movements. They let out a high-pitched squeak if threatened.
• As an arboreal species, they are often spotted about on trees. However, instead of running on all fours, they leap from one branch to the other.
• They have varied vocalizations, like a loud piercing call, a soft, sweet trill similar to the noises made by birds, and a chirping sound, especially in groups.
• Tarsiers secrete a scent from a gland near their mouths. The female uses it to mark her mate, while the males mark their territory with their urine. Females also perform social grooming, removing dead skin and parasites, on adult males and their offspring.

Predators

Due to their nocturnal habits, the Philippine tarsier is often preyed upon by owls, which can easily spot them moving about at night among the tree canopy. Other predators include large birds, civets, certain reptiles like snakes and lizards, and wild cats.

Adaptations

• Like other tarsiers, it can rotate its head up to 180⁰ while keeping the rest of its body still. This allows it to better survey its surroundings and silently wait for prey.
• As a primarily nocturnal species, their extremely large eyes have evolved to cope with the darkness of the night. This gives them excellent vision in low light. However, their color vision remains terrible due to the presence of rods in their retina. In addition to this, their visual cortex is enormous.
• Their limbs are powerful enough to allow them to jump 40 times their own length.
• The Philippine tarsier’s narrow tail gives them proper body balance.
• Like other primates, they have an opposable first toe, which helps them hold things, and have specialized claws for grooming themselves.
• They have excellent hearing due to their big, membranous mobile ears, which allow them to hear any distinct movement clearly.

Mating and Reproduction

The Philippine tarsier is monogamous, with the mating season spanning between April and May. After copulation, the male deposits a mating plug in the female’s genitalia.

Life Cycle

Once a gestation period of around six months passes, the female tarsier gives birth to a single offspring. Their infants are born with their eyes open and covered with hair. The baby tarsiers are carried by their mothers in their mouths. A newborn can cling to branches soon after birth, and in less than 30 days, they start to leap like adults. The mothers breastfeed their offspring for two months, after which they begin to hunt for insects for food.

Philippine tarsiers reach sexual maturity at two years of age.

Conservation Status

As of 2008, the IUCN has classified the Philippine tarsier as “Near Threatened” or “NT”. It used to be classified as “Endangered” or “EN” in 1986, 1988, and 1990.

The main threats to this species have been the loss of its habitat and poaching due to pet trade. This has caused their population to drop drastically, leading to several conservation efforts by groups such as the Endangered Species International (ESI) and the Philippine Tarsier Foundation. The former established a sanctuary for the tarsiers where endangered plants are also raised.

Interesting Facts

• Due to their cute appearance, there is a demand for these tarsiers as pets. But they do not survive for long in captivity, with their life expectancy dropping to 2-12 years. They have a tendency to commit suicide due to the stress of living in captivity.
• Locally they are known as mawumag in Cebuano and other Visayan languages, and magô in Waray.