Transcription
Can animals really talk?
This is Professor Toshitaka Suzuki. For the past 20 years, he studied a small bird called the Japanese tit. And his work shows that these birds don't just make sounds, but use specific words and even grammar to communicate. We covered how he proved this in a recent video, but don't worry, you don't need to have seen it for this video to make sense.
In this video, we're going to go one level deeper and take a look at how early these birds begin to understand language, whether different species can communicate, even across different regions, and whether birds ever use language to lie. To understand how any of this is possible, we need to step back to the very beginning of Suzuki's research.
At a young age, Suzuki says he's always loved to observe animals, whether it was the birds outside his window or insects that he would catch and observe in a box. That curiosity followed him into bird watching in high school and eventually into studying the tits in university. After graduating, he rented a small hut in the Nagano forest near Mount Asama and lived with the birds for years to continue his research. He built nest boxes by hand, installed tiny cameras inside, and placed them all across the forest. And before long, he sees not only his first tenants [music] move in, but also that many of them have laid eggs inside. And he writes that he almost teared up the first time he saw this.
When the chicks first hatch, they are effectively blind, but highly sensitive to sound. They quickly learn to recognize their parents' calls. And by around day 15, they begin to understand the meaning of different alarm sounds. [music] And there's a critical detail here. Chicks don't normally leave the nest until around day 18. And this process typically takes about half a day. Keep that in mind as it's really important for what we're about to look at next.
On June 10th, 2008, while Suzuki was recording the birds, he noticed the call he had never heard before. Pay close attention to this sound. >> He would later discover that this call "ja" he uses a lot of onomatopoeia in his research. So you'll have to bear with me. He referred to the word snake and we break down exactly how he proves this in the previous video. But in that moment, it really confused him because he has spent years observing these birds every day and he had never heard this call before.
When he looked closer, he noticed the snake slowly crawling towards the nest. So he dropped everything, ran over and grabbed the snake by its neck to defend the chicks. But when he checked inside, only five chicks remained from the original 10. He was certain the snake hadn't eaten any of them, and normally the chicks don't leave the nest until around day 18, but this was only day 15. He couldn't figure out what had happened. So, he took the snake with him to test the hypothesis. He decided to place the snake in a glass box near a different nest and observe how the tits behaved. And sure enough, when the tit birds made the "jar jar" call, every chick evacuated the nest within seconds.
This helped explain something remarkable, and he hypothesized that while chicks develop the ability to fly around day 16, they don't use it unless there's an emergency. That would explain why only five chicks escaped in the earlier encounter, as the others simply hadn't developed that ability yet. Over the next few years, he conducts a range of experiments where he introduces different predators near the nest. And for all other predators, the birds instead made this sound: "Pitsby," which is a general alert call. It turns out snakes require a different call because unlike other predators, they can invade nest holes. And what's even more interesting is that the chicks learn this at a very young age. Pay close attention to what happens when young chicks first hear the "Pitsby" sound. >> [music] [laughter] >> You can see that they fall silent and duck their heads to hide. So why is that? [music] Now, let's take a look at what happens when they hear the "jar" sound. All of them immediately flee the nest because against snakes, flying away is the only way to survive. Here's the same clip, but from the outside.
What's really incredible about this is that at this point, these chicks have never even left the nest before or seen different predators, but are able to understand different calls and respond appropriately. This isn't something that humans are born knowing, as our language needs to be learned slowly over years. And it implies there's something fundamentally different about how birds learn and inherit language.
Now, one of the biggest questions from the last video was, can different species of birds and even birds from different regions understand each other? So, let's take a look at that next. As Suzuki continued his research, he pondered this same question. And when he paid close attention to other birds in the forest, he notices that the tree sparrows in the area seem to consistently react to the tit bird calls, and they seem to be able to understand them and even use them as warnings for predators. So, he decides to test this. And what you're about to see is live footage from a news program where Suzuki runs one of these experiments live at the local park. You can first see here that the tree sparrows on the ground looking for food. The first sound he plays is "gigi," meaning gather. It doesn't signal any danger, and there's no response from the sparrows. Next, he plays "Pitsby" and "gigi," meaning alert and hawk. And you can see the sparrows almost immediately take off the trees. >> When this footage aired, it got widespread interest from researchers and news outlets all across the world. And at the time, a Finnish TV program contacted Suzuki with one question: Would the Finnish great tits react to the calls of the Japanese tits, especially since some of their sounds were already quite similar?
So, Suzuki was quite interested about this himself, and he sends the recordings of two specific calls across. The first is "Pitsby," meaning alert and gather, and then the two in the reverse order, "gigi Pitsby." A quick aside for those who haven't watched the previous video: the tit birds only responded when the calls were played in the correct order, but not when it was reversed. And this became one of Suzuki's key pieces of evidence for their calls having grammar. But let's take a look together at what the Finnish researchers sent back.
They first place a speaker on the tree and play "Pitsby gigi." And you can see the Finnish tit reacting the same way as the tit birds in Japan by approaching the speaker. Next, they play the version that's reversed. And again, the tit bird exhibits the exact same behavior as the tit birds from Japan, where they don't react and approach the speaker. This is pretty amazing, right? And when he sits down to analyze the waveforms of the calls between the two species, he notices that despite there being differences in pitch and sound, the overall structure is largely consistent. For example, instead of "Pitsby gigi," it's "Pitsby tit" for the Finnish tits.
So, the fact that different species of birds may be able to understand each other makes him wonder how far this really goes. He notices that the willow tits in the area seem to make a similar call when they try to gather together. Instead of "gigi," it's more like "did." So, he thinks to himself, how can he test this further in an experiment?
Around this time, he was watching one of his favorite comedians, Mr. Oshiba, who would often slip in English words into a sentence. For example, instead of saying "nemini mizu," which means water poured into your ear, he would say "nei water." The audience would still understand the sentence as it follows grammatical rules and find it quite humorous. But people don't naturally speak like this. So what happens when you do something similar for birds?
So he decides to combine "Pitsby" from the Japanese tit and "did" from the willow tit and plays it to the Japanese tits, and it turns out they can understand. He also does this in reverse, and in that situation, they don't understand. So, this shows that birds are not only multilingual, but are applying a level of grammatical reasoning that allows them to interpret combinations of calls that aren't natural in nature. And it suggests something similar to how different dialects work in human language.
As his work spread, some critics argue that these birds only use two words, and that real sentences require three or more. But Suzuki pushes back on that idea. He argues that just because it's two words, does that really mean it's not a sentence? Is it not more likely that their sentences don't need to be very long to communicate what they need in the forest?
A more interesting challenge was whether the birds were actually interpreting sentences or just reacting to multiple sounds at once. And this made him pause to think because it was a real possibility that the birds were interpreting the two calls separately. So he designs a simple experiment where he plays "Pitsby" and "gigi" out of one of the speakers, and then plays "Pitsby" and "gigi" separately from two different speakers. And the result is clear. The tit birds only respond when the two words were played consecutively from the same speaker, which means they're not just reacting, but rather actively interpreting what they're hearing.
So if birds are capable of interpreting meaning and structure, do they ever use language to lie? During his studies, he noticed something unexpected. When the tit birds were faced with larger predators, they would occasionally also make the "heih heih" call, the signal for hawk, even when there was no hawk around. And this would make slightly larger predators like crows stop chasing them and instead go into hiding. He even encountered a version of this firsthand. On one occasion, when he opened the nest box, he heard the tit birds make their snake alarm call, which startled him as it made him think there was an actual snake inside. And for this to work, it implies there's not only language, but also understanding between species. And Suzuki finds that this is not just limited to birds. For example, smaller animals like squirrels can also understand their calls. When the tit birds make the "heih" sound, they will also stop what they're doing and immediately dart into hiding, and they've learned to pay attention to the tit birds because they are perched higher in the forest and can see predators more clearly.
After spending so many years in the forest and living alongside these animals, Suzuki began to notice something unexpected. Not just about the birds, but about himself. [laughter] Suzuki believes that our ancestors likely understood the language of animals, but we lost that ability at some point in time. Over time, in our pursuit for technology, intelligence, and to differentiate ourselves as human, we may have lost a part of us that makes us human.
He's been able to stay passionate about his work for over 20 years because he wants to encourage everyone to turn their eyes to nature again to notice the animals that live alongside us. He shows that we don't need advanced equipment or artificial intelligence or complex [music] models to begin understanding animals. All we need is a curious mind and a lot of patience. Sometimes learning just one word is enough to completely change how we see the world around us.
When Suzuki looks into the forest, he imagines a world like Studio Ghibli or Pokémon, one where animals are frequently interacting, responding to each other, and sharing information. And he worries that it would be a shame if we lived alongside that world without ever really noticing it. So, the next time you take a walk in the forest or go for a hike or even just to walk through your neighborhood, pay close attention. Maybe the animals around you are telling you to be careful or where to find food. Or maybe they're simply wondering why we never answer back.