This article is from
Creation 36(4):27–29, October 2014

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The tarsier’s ‘secret speech’


Not much bigger than a human hand (when in resting posture on a tree branch), the tarsiers of south-east Asia are the smallest of the primates. They tend to keep their hind legs, which are twice as long as their bodies, folded up ‘frog-style’, except when leaping on their insect prey—see photo below. They have proportionally the largest eyes (i.e. relative to head and body size) of any mammal.

It used to be thought that when the Philippines tarsier (Tarsius syrichta) opened its mouth it was simply yawning or stretching—because we couldn’t hear any sound. But when researchers took equipment used to record bats’ high-frequency chirps into the jungle, they discovered that these tiny nocturnal big-eyed primates were communicating with each other using ‘pure ultrasound’.1,2,3

The dominant frequency of the tarsier’s ultrasonic call was 70 kilohertz, ranging up to 75 kHz—among the highest recorded for any terrestrial mammal. And the researchers discovered that tarsiers could hear up to 91 kHz (way beyond the 20 kHz limit of human hearing).

“Philippine tarsiers have often been described as quiet,” explained lead researcher Marissa Ramsier of the Humboldt State University in California. “But they’re screaming and talking away, and we just didn’t know it.”4

For the tarsiers, “ultrasonic vocalizations might represent a private channel of communication” the researchers suggest, i.e. a ‘secret speech’ that predators,5 prey and competitors cannot hear. Also, at least some of their prey species—e.g. moths and katydids—are known to emit sounds in the ultrahigh frequency range, on which the tarsier could easily ‘zoom in’ for the kill.

Not unexpectedly, Science magazine’s report on the discovery couldn’t resist putting an evolutionary ‘spin’ on what to most sensible people would be a staggeringly obvious example of evidence for a Designer. They quoted Mark Coleman, of the Midwestern University in Glendale, Arizona, who was not involved in the study, as surmising that this ultrasound ability was commonplace in ‘early mammals’—“the better to hide from hungry dinosaurs”. Coleman suggests that tarsiers are one of the few species to have retained this ability. “They’re kind of a holdover from this really ancestral mammal … where high-frequency communication was the norm.”4

However, an astute observer will note that even if evolutionist Coleman were right (which he isn’t), the loss of a function does not explain how it arose in the first place!

For a final word, let’s instead go back to one of the co-authors of the actual study, Sharon Gursky-Doyen of Texas A&M University, who was appropriately awed by the discovery of this amazing communication ability in tarsiers.

“It was mind-boggling,” she said. “It makes you reevaluate everything you’ve done, heard, and observed.”3

Tiny tarsier’s evolution-defying leap

tiny-tarsier Photographer: Jürgen Freund // naturepl.com // juergenfreund.com

With pinpoint accuracy, this spectral tarsier (Tarsier tarsier) positions itself mid-air to complete a perfectly-targeted leap with a successful capture of a midnight snack. At rest tarsiers are only about 10 cm (4 inches) tall—the shortest primate in the world. But their long, powerful legs enable them to leap on their insect prey from up to 6 metres (20 ft) away! Note the positioning of the legs for landing—their essential utility as shock absorbers perfectly complements the springboard power they provide for launches.

Considering the degree of coordinated precision on display here, how could anyone entertain the notion that the tarsier is ‘primitive’ (which presumes an evolutionary origin), rather than designed by God? It’s almost as if the thoroughly evolution-proclaiming New Scientist recognized what is at issue here, when they recently tried to dismiss the contradiction by writing of a photo similar to this one, “They [tarsiers] might be primitive on the primate family tree, but they are still pretty cool.”1

Photographers Jürgen and Stella Freund travelled to Tangkoko National Park in North Sulawesi, Indonesia, and were rewarded with this stunning shot. Stella told us, “This is the prime tourist attraction here and the primates are used to people ogling them at about sunset. These nocturnal creatures would forage the forest for insects and come back to their sleeping tree by 5am the next day. For the first 4 days, we were going to the tarsier’s sleeping tree as they woke up at 5pm. It was always a short photo session because they’d be jumping off and gone into the woods in no time. As we were getting desperate not having quality time to shoot them, our guide said the very best time was early in the morning at 4am as they came back from their night’s foraging. We woke up at 3:30am, walked to their fig tree home and waited for them to arrive. We would be alerted by their squeaks! And indeed they would stay out of their sleeping tree to hunt some more insects and get photographed, before finally going to bed once the day starts lighting up.”


  1. Hooper, R., Cute but deadly furball launches death attack, newscientist.com, 18 March 2014. (Also appeared in New Scientist 221(2960):26–27, 15 March 2014, under the headline, ‘Cuteness, weaponised’.)
Posted on homepage: 1 February 2016

References and notes

  1. Corbyn, Z., The only primate to communicate in pure ultrasound, newscientist.com, 8 February 2012. Return to text
  2. Ramsier, M., and 7 others, Primate communication in the pure ultrasound, Biol Lett. 8(4):508–511, August 2012 | doi: 10.1098/rsbl.2011.1149. Return to text
  3. Garthwaite, J., Edge of evolution: Silent screech of the tarsier, discovermagazine.com, 29 October 2012. Return to text
  4. Strain, D., Tarsiers communicate in secret speech, sciencemag.org, 7 February 2012. Return to text
  5. E.g. birds and snakes. Return to text

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