I thought it was a baby crying from a distance, but when I got closer I realized it was a bird.

Produced by: Science Popularization China

Produced by: Su Chengyu

Producer: Computer Network Information Center, Chinese Academy of Sciences

Before we start the article, let’s watch a video:

If you don't see the picture, but only listen to the sound, and ask you what animal makes this sound, I think everyone will answer without hesitation: "Isn't this the sound of a baby crying?"

Isn't it a bit weird and scary - animals actually make human sounds. This is a video posted on social media by Sydney's Taronga Zoo on August 30 this year.

This reminds me of a science fiction movie called Annihilation. In one scene, the protagonist and his companions heard a cry for help in the house: "Help me, help me..."

When they heard the sound, everyone thought it was the cry for help from the missing teammates, but it was actually just a mutated monster that imitated the human distress signal to trap the humans who wanted to rescue them.

This is probably the scariest scene in the film. The main reason why everyone finds it so scary is that this monster triggers the "uncanny valley effect" of humans.

The so-called "uncanny valley effect" refers to the fact that as the degree of anthropomorphism of an object increases, humans' emotional response to it shows an increase-decrease-increase curve. The "uncanny valley" is when the robot reaches a "close to human" similarity, and humans' favorability suddenly drops to the range of disgust.

Uncanny Valley Effect (Image source: Wikipedia)

This monster that makes the "help me" sound is right within the range of the uncanny valley. Similarly, this is why everyone thinks the bird's cry in the video is creepy.

So what kind of bird is this, and why can it imitate the sound of a human baby crying?

The magnificent lyrebird at Taronga Zoo (Image credit: Taronga Zoo Sydney)

Superb Lyrebird: The "Mockbird" of the Animal Kingdom

This bird from Sydney's Taronga Zoo is a "superb lyrebird", which is endemic to Australia.

The bird is so called because the male has an intricately crafted tail that resembles an ancient Greek musical instrument called a lyre.

In the sixth episode of David Attenborough's nature documentary Birds of a Life, the magnificent lyrebird is described as a songbird that can imitate 20 sounds, ranging from animal sounds, such as dogs barking and cats meowing, to non-animal sounds, such as car alarms, chain saws, and various camera shutters.

Superb Lyrebird (Image source: Wikipedia)

The magnificent lyrebird, named Echo, from Sydney's Taronga Zoo, can mimic the sounds of a power drill, a fire alarm and an immediate evacuation, according to keepers.

The administrator said that Echo started practicing imitating the crying of human babies about a year ago, but it is not clear how he learned it. It is probably learned from some unhappy tourist baby.

Superb Lyrebird (Photo credit: Johncarnemolla/Dreamstime.com)

What is the purpose of the superb lyrebird's mimicry of sound?

According to the Audubon Society's study of superb lyrebirds, male lyrebirds primarily use their gift of mimicry for courtship.

June to August every year is their breeding season. The male bird can sing continuously for 4 hours a day, worthy of being called the "King of Karaoke".

Since he is the king of karaoke, he is definitely not an original singer. The male lyrebird's courtship song is a mix of different bird calls heard from the surrounding environment, and sometimes even some non-bird sounds are mixed in.

The superb lyrebird's mimicry skills are not only used for courtship, but also to deceive predators.

According to a study published in the journal Current Biology on February 25, 2021 by Cornell University, the superb lyrebird can not only imitate the sound of one other bird, but also imitate the chaotic calls of a flock of birds. When predators hear this, they think they are facing not one bird but a flock of birds, and they dare not act rashly.

Superb Lyrebird (Image source: Wikipedia)

Why can the superb lyrebird imitate so many sounds?

All birds, including superb lyrebirds, have more complex vocalizations than other animals. Some songbirds, like the superb lyrebird in this article, or starlings and parrots, have even more complex vocalizations than other birds.

Image source: Reference 1

Let's start with the vocal organs. Humans rely on the larynx to produce sound, while birds rely on the syrinx and syrinx muscles. The human vocal organ starts from the vocal cords at the glottis of the larynx and ends at the tip of the tongue. Its total length from front to back is about 20 cm, and it forms a right angle with the body axis.

The total length from the syrinx to the tip of the tongue of lyrebirds, starlings, and parrots is about 15 cm, and the angle formed with the body axis is also close to a right angle. This is one of the reasons why birds can imitate other sounds, make more complex sounds, and even imitate human speech.

However, no superb lyrebird that can imitate human speech has been found so far. The most it can do is imitate the crying of a baby as mentioned above.

It is said that it can imitate more than 20 different sounds only because these magnificent lyrebirds are exposed to more than 20 sounds, but if it could hear more sounds, it would probably be able to imitate more.

No wonder Sir David Attenborough once said that the superb lyrebird has one of the "most elaborate, complex and beautiful calls in the world".

It can be said that: "There was a ventriloquist in Australia who suddenly raised his hand to play the harp, and all the sounds stopped. When the screen was removed and the inside was looked at, there was only a gorgeous lyrebird."

References:

(1) Lan Shucheng. Human vocal cords and animal vocal organs[J]. Bulletin of Biology, 1985, 9.

(2) https://twitter.com/i/status/1432489666897453057.

(3) https://australian.museum/learn/animals/birds/superb-lyrebird/.

(4) https://www.cell.com/current-biology/pdfExtended/S0960-9822(21)00210-4.