What if the secret to understanding the origins of human language lay in the calls of an orangutan?
At Cologne Zoo in Germany, a female Bornean orangutan named Tilda has stunned scientists with her ability to produce human-like vocalizations, something never before documented in a wild-born great ape.
Unlike typical orangutan calls, Tilda can click her tongue, whistle, and even create sounds similar to human consonants and vowels—and she does it for a very specific reason: to grab the attention of her zookeepers when she wants food.
This discovery, published in the journal PLOS ONE, challenges long-held assumptions about the vocal limitations of great apes and suggests that our early ancestors may have been capable of more complex speech than previously believed.
Could this mean that the roots of human language run deeper into our evolutionary past than we thought?
Tilda’s Incredible Human-Like Calls
Orangutans are already known for their impressive intelligence and unique vocal repertoire, but Tilda is different.
Researchers studying her noticed two distinct types of vocalizations that are unheard of in other orangutans:
A rhythmic tongue-clicking sound—comparable to the clicking language of the San people of the Kalahari Desert in Africa.
A rapid sequence of grumbles—which resembles human vowel-like sounds.
In addition to these, Tilda can whistle, a skill rarely observed in orangutans.
But here’s where it gets even more interesting: Tilda uses these sounds intentionally, not randomly.
Whenever she sees her human caretakers handling food, she immediately begins making these attention-seeking calls, often pointing or clapping at the same time.
Biologist Adriano Lameira from the University of Amsterdam, the lead author of the study, describes the meaning behind these sounds:
“They are what we would call attention-gathering or come-hither calls, which indeed are mostly used when the human caretakers are handling food. I would translate them into, ‘Come here and give that food to me!'”
This revelation is groundbreaking because it suggests that orangutans—like humans—can modify their vocal behavior to achieve a desired outcome.
A Contradiction to What We Thought About Ape Vocalization
For years, scientists have assumed that the vocal abilities of great apes were rigid and hardwired, meaning that they lacked the flexibility to produce new or learned vocalizations.
Tilda’s case shatters that assumption.
The research team argues that the long-standing belief that great ape calls are biologically fixed is actually due to our limited understanding of how these animals communicate.
Lameira explains:
“The notion that great ape calls are hard-wired and inflexible is likely an artifact of our very poor understanding of the call communication of these species, rather than that their calls are factually hard-wired or inflexible.”
In other words, apes might be capable of much more than we’ve given them credit for—and we’re only now beginning to realize it.
This also raises a new question: If an orangutan can produce speech-like sounds with no formal training, could our early human ancestors have done the same?
What This Means for Human Speech Evolution
The ability to control vocal structures is a key component of human speech.
While many animals communicate vocally, few can intentionally modify their sounds the way humans do.
Tilda’s vocal skills suggest that the capacity for flexible speech-like communication existed long before Homo sapiens evolved.
If orangutans, chimpanzees, and gorillas can produce and modify vowel- and consonant-like sounds, it strengthens the theory that our early ancestors—such as Neanderthals or Homo erectus—might have had primitive speech-like abilities.
Linguist Mark Sicoli told Discovery News:
“What Bonnie (another whistling orangutan) shows is that anatomically, whistling would have been in the range of potential sound-making behavior of Archaic Homo sapiens, including Neanderthals and earlier hominins like Homo erectus and Australopithecines.”
This means that the origins of human speech might not have suddenly emerged with Homo sapiens but could have been gradually developing over millions of years.
Other Apes Are Showing Signs of Speech-Like Abilities
Tilda isn’t the only great ape demonstrating unexpected vocal skills.
Bonnie, an orangutan at the National Zoo in Washington, D.C., has taught herself to whistle—seemingly for fun.
Koko, the famous gorilla, was able to use sign language and make sound-based associations with certain words.
Chimpanzees have been observed making rapid “chattering” sounds that resemble human speech patterns.
The fact that multiple great apes in different locations are displaying speech-like abilities suggests that this may not be a rare or isolated behavior but rather a widespread cognitive ability that we’ve overlooked.
How This Could Change the Way We Study Human Language
Traditionally, linguists and anthropologists have assumed that our ancestors needed some kind of genetic “breakthrough” before developing speech.
However, the gradualist theory suggests that speech didn’t emerge suddenly—it evolved slowly from simpler vocal behaviors, like the ones we now see in great apes.
By studying Tilda and other vocal apes, researchers may be able to pinpoint the missing evolutionary links that led to the formation of complex human speech.
Future studies will focus on:
Examining how wild orangutans and chimpanzees use vocalization in their natural habitat.
Investigating whether apes can be trained to develop even more human-like speech patterns.
Comparing ape vocal control with fossil evidence from early hominins.
Are We Closer to Unlocking the Mystery of Human Speech?
Tilda’s vocal abilities suggest that the foundation for human speech may have existed long before we ever imagined.
If orangutans and other apes can modify their vocalizations and use them with intent, it challenges the assumption that our ancestors suddenly “discovered” language out of nowhere.
The discovery raises profound questions:
Were early humans already using primitive speech 2-3 million years ago?
Can other great apes be trained to mimic human-like language patterns?
What other vocal abilities are hidden in the animal kingdom that we’ve yet to uncover?
As researchers continue to study Tilda and her remarkable abilities, we may soon find ourselves rewriting the history of human speech evolution.
And to think—it all started with an orangutan trying to ask for more food.
