The Horsfield’s Tarsier: The Only Species Found in Borneo & Sumatra

Finding Tarsiers in the Jungle

Every night during our stay at Danau Girang Field Centre in Borneo (read about our stay here), we went out into the jungle and explored.

We took the following photos over three nights in different locations of three individuals. We couldn’t believe the luck we had in finding them! From their giant, bulbous eyes to their body-length tails, they were amazing to see. Watching them leap through the trees with such speed and agility was a real treat.

Click on these photos for a larger image:


A Few Tarsier Facts

  • The tarsier’s claim to fame is that their eyes are the biggest of any mammal relative to their body weight. In fact, the volume of one eyeball is almost the same volume as its brain!
  • The name ‘tarsier’ refers to the elongated tarsal bones in the heel and ankle region. Serveral of these tarsal bones are longer in the tarsier than those of any other primate.
  • Tarsiers are the only extant (still living) entirely carnivorous primate. They eat mainly insects and the occasional small vertebrate.  They locate prey primarily by sound, and then catch the prey with their hands.
  • Most nocturnal primates have a reflective layer in the back of the eye called the ‘tapetum lucidum’. Tarsiers, however, do not. The tapetum lucidum is what produces the ‘cat’s eye’ reflections when you shine a light towards them at night. So, as you can imagine, tarsiers are a lot more difficult to spot; an adaptation that has made it difficult for both poachers and scientists alike!
  • The unique shape of a tarsier’s spine means that it is capable of rotating its head nearly 360 degrees. Check out this photo to see what we mean:

Cephalopachus bancanus [HORSFIELD'S TARSIER] Sabah, Borneo 10-10-2017 (4)


The Horsfield’s Tarsier (Cephalopachus bancanus)

  • The Horsfield’s tarsier is the only species of tarsier found in Borneo and Sumatra. It is also the only tarsier in the genus Cephalopachus.

    (NB: The Horsfield’s tarsier is often also put in the genus, Tarsius, with all other living tarsiers. But, apparently it is quite distinct from the Philippine tarsier and the various tarsiers of Sulawesi and nearby islands, so some scientists have placed it in the separate genus, Cephalopachus. If anyone can tell us where the current taxonomy is at, feel free to let us know in the comments!)
  • The average sizes and weights of the Horsfield’s tasier are:
    Head-body length: 11.5 – 14.5 cm
    Tail length: 20 – 23.5 cm
    Female weight: 107 – 127 g
    Male weight: 122 – 134 g

It’s awesome to think that we have actually met these cool critters in person. Thank you to the Danau Girang team for taking us out!


Want to Read More?

If you’d like to read more about our trip to Borneo and the wildlife we encountered there, check out some of our other blog posts here:

Zoomology Lantern Bug Post

Zoomology Forest Frogs


References and Further Reading

Arkive Website – Tarsius bancanus – http://www.arkive.org/horsfields-tarsier/tarsius-bancanus/
(Retrieved 13 November, 2017)

IUCN Red List – Tarsius bancanus – http://www.iucnredlist.org/details/21488/0
(Retrieved 13 November, 2017)

IUCN Red List – Tarsius bancanus ssp. borneanus – http://www.iucnredlist.org/details/39763/0
(Retrieved 13 November, 2017)

Orang Utan Republik Foundation – Other Primates of Borneo and Sumatra – https://www.orangutanrepublik.org/become-aware/biodiversity/other-primates-of-borneo-a-sumatra
(Retrieved 13 November, 2017)

University of Wisconsin, National Primate Research Center – Primate Info Net: Tarsier – http://pin.primate.wisc.edu/factsheets/entry/tarsier
(Retrieved 13 November, 2017)

Wikipedia Website – Horsfield’s Tarsier – https://en.wikipedia.org/wiki/Horsfield%27s_tarsier
(Retrieved 13 November, 2017)

8 Comments Add yours

  1. So interesting, what a strange and unusual creature! Like something out of Lord of the Rings. Weird how it can twist its head around like that!

    Liked by 2 people

    1. Thanks, Liz. 🙂 It really is strange how it turns its head like that. Apparently it can’t moves its eyeballs in its sockets, so it has adapted to rotate its entire head instead (much like an owl)!

      -Emma

      Liked by 2 people

      1. Oh yeah, right! Just like an owl, its kinda spooky how they move their heads too! Thanks 🙂

        Liked by 2 people

      2. Yes! It’s definitely a bit of an ‘Exorcist’ move! XD

        -Emma

        Liked by 2 people

  2. Another very interesting post. You guys should sign up for the next Planet Earth!

    Liked by 1 person

    1. Haha, thank you, Helen! Well, if they asked us, we wouldn’t say, ‘no’! 😀

      -Emma

      Liked by 1 person

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