Speaker 1: Welcome to brain Stuff, a production of iHeartRadio, Hey brain
Speaker 1: Stuff Lauren bogelban here. The unique characteristics of tarsiers have
Speaker 1: caused people to call these tiny primates many names, from
Speaker 1: goblins to gremlins to grogu. To be fair, they do
Speaker 1: have prominent and sometimes pointed ears and an uncanny eyeballed
Speaker 1: ahead ratio for a creature that's so closely related to us.
Speaker 1: The tarsier is a small type of primate found living
Speaker 1: in the forests of Southeast Asia and the Pacific Islands.
Speaker 1: The taxonomical tarsiar family contains three genera, some sixteen species
Speaker 1: and seven subspecies depending on who you ask. It's an
Speaker 1: ongoing field of research, and I'm pretty sure biologists enjoy
Speaker 1: arguing about taxonomy. But whatever their exact classification, tarsiers all
Speaker 1: occupy the dense forests of Malaysia, Indonesia, Brunei, and the Philippines,
Speaker 1: though every species has different characteristics. Tarsiers tend to range
Speaker 1: in side from around three and a half to six
Speaker 1: inches long that's about nine to fifteen centimeters, making them
Speaker 1: among the smallest known primates. Like owls, they can rotate
Speaker 1: their head nearly one hundred and eighty degrees in both directions.
Speaker 1: Tarsiers have round heads with a small snout and large
Speaker 1: ears that look a bit like muscleshells. They also have round,
Speaker 1: furry bodies. Their thick, short fur can range in color
Speaker 1: from gray to black or tan to yellow, orange to
Speaker 1: red to brown, or some combination. They have long arms
Speaker 1: and legs. Their ankle bones, or tarsals, are particularly long.
Speaker 1: That's where they get their name. Those long legs and
Speaker 1: ankles allow them to jump and leap like lemurs. Their
Speaker 1: fingers are also exceptionally long, with small sticky pads at
Speaker 1: the ends to help them cling to trees where they
Speaker 1: live and hunt for prey. Their tails can be twice
Speaker 1: their body length. Some species of tarsiers have hairless, a
Speaker 1: rat like tails, while others have tufts of fur along
Speaker 1: the length of the tail or at the end. Altogether,
Speaker 1: they look sort of like someone stuck frog legs on
Speaker 1: a highly caffeinated teddy bear. Tarsiers like hanging out in shrubs, trees,
Speaker 1: and other vegetation above ground level. This vantage point allows
Speaker 1: them to rest more at ease from predators and also
Speaker 1: to hunt for their small prey. They are the planet's
Speaker 1: only primate species that is entirely carnivorous, but within that category,
Speaker 1: they eat whatever their forests have to offer, including insects, frogs, crabs, lizards, birds, bats,
Speaker 1: and snakes, and different species are variably social, but they
Speaker 1: tend to form small groups that gather to share food,
Speaker 1: protect each other from predators, play, groom, snuggle, and mate.
Speaker 1: They communicate with calls that are outside the range of
Speaker 1: human hearing. But okay, we have to talk about what
Speaker 1: large eyes they have. Even four nocturnal mammals, their eyes
Speaker 1: are enormous compared to their body size. They're the biggest
Speaker 1: eyes of any mammal relative to their body weight. Their
Speaker 1: eyes are very round in shape and often a striking
Speaker 1: gold color. A tarsiar's lack a tpedum lucidum, which we've
Speaker 1: talked about before on the show. It's a reflective layer
Speaker 1: inside the eye behind the retina that most other animals
Speaker 1: have if they are active at night. The tpedum lucidum
Speaker 1: is important to nocturnal vision because it bounces light back
Speaker 1: at the retina, giving the eye a second chance to
Speaker 1: gather that light. For the article of this episode is
Speaker 1: based on how Stuff Works. Spoke with Myron Shekel PhD,
Speaker 1: a biological anthropologist imprimatologist with Western Washington University. He said,
Speaker 1: one of the things we know is when you take
Speaker 1: your flashlight and you shine it into a forest at night,
Speaker 1: lots of animals have a very strong eye shine that
Speaker 1: comes to right back at you. Cats and dogs, lemurs,
Speaker 1: bush babies, and lorises. Tarsiers don't have that. Humans, monkeys
Speaker 1: and apes don't have that. So the tarsier I had
Speaker 1: to compensate and became a lot bigger than you'd expect.
Speaker 1: Shikehl has conducted decades of research contributing to what we
Speaker 1: know about tarsiers and about primate evolution in general, he said.
Speaker 1: When I handed in my first grant proposal, which would
Speaker 1: have been in nineteen ninety three nineteen ninety four, one
Speaker 1: of the reviewers commented, Shakelle has outlined a career's worth
Speaker 1: of research, and now I'm just about to the point
Speaker 1: where I can publish the answer to the questions I
Speaker 1: posed in that research grant proposal all those years ago.
Speaker 1: It's exactly the tarsiers lack of this reflective layer that
Speaker 1: offers an exciting insight into primate evolution. When primates became diurnal,
Speaker 1: a meaning active during the daytime, they eventually lost the
Speaker 1: need for a pedem lucidam, Schakel said, So it looks
Speaker 1: like tarsiers spent some amount of time in their history
Speaker 1: as a diurnal primate. If they then reversed and became
Speaker 1: nocturnal again, they had perhaps already lost that topedum lucidum.
Speaker 1: Since the first scientific description of tarsiers was published around
Speaker 1: seventeen seventy seven, scientists have debated where tarsiers belong on
Speaker 1: the primate evolutionary tree. They jump, climb, and live like lemurs,
Speaker 1: but have physical characteristics similar to apes and humans, like
Speaker 1: that lack of a topedum lucidum and the fact that
Speaker 1: they have a dry nose instead of a wet one,
Speaker 1: which is one of the main ways that researchers categorize primates.
Speaker 1: Chakel said, At the level of genomic data, where we
Speaker 1: can look at really major changes, the evidence is becoming
Speaker 1: clearer that tarsiers are our cousins. However, tarsiers are notoriously
Speaker 1: elusive and difficult to study, especially without the dead giveaway
Speaker 1: eyeshine that other nocturnal species have. Chakel and his colleagues
Speaker 1: identified several new species of tarsiers on the Indonesian island
Speaker 1: of Sulawesi, where there was long thought to be just
Speaker 1: a single species. But unfortunately, tarsiers do poorly in captivity.
Speaker 1: No group that's been brought into captivity for study or
Speaker 1: tourism has survived. It's hard to replicate their prey rich
Speaker 1: natural environment, and like other primates, they're easily stressed out.
Speaker 1: Tarsier conservation is becoming an increasingly important topic, as some
Speaker 1: species of tarsiers have made the endangered or Vulnerable species
Speaker 1: list due to their limited population, a lack of protected areas,
Speaker 1: and deforestation and mining of what territory they do inhabit.
Speaker 1: Just for one example, take the main island of Sangi
Speaker 1: Hey in Indonesia. Sangi He has an endemic species of tarsiers, endemic,
Speaker 1: meaning that the species is only found there. The saying
Speaker 1: gie Hey tarsier was recently added to the list of
Speaker 1: twenty five most endangered primates in the world after the
Speaker 1: island opened to gold mining. Because there are more tarsier
Speaker 1: species than there are scientists studying them, it's difficult to
Speaker 1: know precisely how endangered some species are across these many islands,
Speaker 1: but hopefully some intentional conservation efforts will help bring species
Speaker 1: back from the brink and prevent more species from becoming
Speaker 1: critically endangered. It'll take a concerted effort and coordination with
Speaker 1: local researchers and experts. Shaquel said, If we keep tarsiers
Speaker 1: in their habitat like in Indonesia, and we simply throw
Speaker 1: a cage around them and use somebody who actually knows
Speaker 1: how to keep tarsiers alive, they stay alive and they breed.
Speaker 1: Today's episode is based on the article the tarsier is
Speaker 1: one weird primate and Yes We're related on how stuffworks
Speaker 1: dot Com, written by Alison Trautner. Brain Stuff is production
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