Saturday, June 21, 2014

Really Weird Animals: The Tarsiers

Here’s a group of weird looking animals for you; the tarsiers.  Native to the rainforests on islands of Southeast Asia, they look like baby aliens!

Philippine tarsier (photo: Wikipedia files)
There is still some debate as to exactly how many known species and subspecies of tarsier there are.  Endangered Species International states that most recently the tarsier family, tarsiidae, is divided up into three genera, which includes 18 species and subspecies of tarsier.  The most well-known is the Philippine tarsier.

Tarsiers are tree-dwellers and among the smallest primates in the world.  For example, the Philippine tarsier measures only about 3.35 to 6.3 inches in height and the Pygmy tarsier about 4 inches, not including the tail.  The length of their tail ranges from 8 to 10 inches long.  Some species have sparsely furred tails while others are more bushy-tailed like the Spectral tarsier.  They all have very large eyes, large ears, soft fur, and long hind legs.  The long legs enable them to leap distances of up to 5 meters between tree branches. 

Tarsiers are nocturnal and their large eyes help them to see extremely well at night.  Their eyes are the largest in relation to its body of any mammal.  Just one of their eyes is heavier than its brain, but around the same size.  Like owls, they cannot move their eyes in their sockets and to compensate they can turn their heads almost 360 degrees around their body.  Their large ears are very sensitive to the tiniest sounds, or sign of prey or predators.  They have long fingers with sticky pads on the end of each which helps them to climb and catch prey.

Philippine tarsier showing long tail (photo: Wikipedia files)
 Tarsiers are the only primates that are strictly carnivorous, eating mostly insects, but occasionally small birds, lizards, and bats.  Unlike other primates, tarsiers do not move around in search of prey.  They sit and swivel their heads around and watch and listen.  Once they spot a prey item, they leap and grab it in their hands.

A few species of tarsiers are known to be monogamous.  Mating can occur any time of the year.  Just one baby is born after a 6-month gestation period.  They are born with fur and eyes open and can cling to branches within one hour and can leap within a month!  They do not build nests, but just place their young in a safe place nearby while hunting.  The mother will also carry her baby around in her mouth or on her back.

Philippine tarsier with baby (photo: the Wikipedia files)
 Most species of tarsiers are endangered or threatened, and some are labeled critically endangered.  Threats include habitat loss, hunting, agricultural pollutants and human disturbance. They are extremely shy animals that prefer to stay away from human contact. 

Unfortunately captive breeding programs have been quite unsuccessful.  Tarsiers do not take well to living or successfully breeding in captivity.  Wild tarsiers that are captured and held in captivity only show around a 50% rate of survival and in many cases they perish quickly of overstress by committing “suicide”. 

Captive Philippine tarsier being handled (photo: the Wikipedia files)
Conservation efforts must focus on their wild habitats and populations.  Legislation has been passed in the Philippines to end the capture of the Philippine tarsier from the wild for the pet trade and to help stop habitat destruction.

Submitted by Sara Oliver, World Bird Sanctuary Naturalist


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