The lyrebird: nature’s finest sound mimic

The superb lyrebird of Australia (Menura novaehollandiae) is perhaps the best vocal mimic in the world, and by “vocal mimic” I don’t mean having the ability to mimic voices, but having the ability to mimic diverse sounds with its voice.

In one of the first posts that appeared on this site in 2009 (only 4 comments!), I showed a video of a lyrebird apparently mimicking a chainsaw, a camera, and a car alarm.  That video is no longer at the original site, but it’s been put on YouTube again, and is just below. Naturally, it’s from an Attenborough show: the “Life of Birds” series.

Amazing, no?

This video has been cited widely, even by National Geographic, but it may not be all it’s cracked up to be. In an article at The Conversation, Hollis Taylor, a postdoc at the University of Technology in Sydney, first explains the birds’ mimicy in the wild:

. . . lyrebirds have a stunning ability to accurately mimic the sounds of the forests they inhabit. Most of their mimicry is of other avian species: calls, songs, wing beats, and beak claps, which they deliver in quick succession.

The avian sound-producing organ is the syrinx. Instead of the usual four pairs of syringeal muscles of other songbirds, lyrebirds have only three pairs. It is not known if this simplification makes them more adept at mimicry, nor is their motivation to mimic entirely clear. There is no evidence to suggest that lyrebirds attempt to fool other species.

While mimicry forms most of their vocal repertoire, lyrebirds also have their own songs and calls. While the “territorial” song can be melodious, the “invitation-display” call sounds mechanical to human ears. Twanging, clicking, scissors-grinding, thudding, whirring, “blick”-ing, galloping — these noisy or metallic sounds are the lyrebirds’ own and not mimicry. Nevertheless, they are often mistaken for that.

But Taylor adds this:

This Attenborough moment is highly popular — but hold on! He fails to mention that two of his three lyrebirds were captives, one from Healesville Wildlife Sanctuary and the other from Adelaide Zoo. This latter individual, Chook, was famed for his hammers, drills, and saws, sounds he reputedly acquired when the Zoo’s panda enclosure was built. Hand-raised from a chick, he was also known to do a car alarm, as well as a human voice intoning “hello, Chook!” He died in 2011, aged 32.

The fact that lyrebirds in captivity mimic human machines and voices with such fidelity should be a substantial enough achievement to warrant our awe.

Based on this (and what I’ll reproduce below), Taylor concludes that there’s no example of a lyrebird in nature imitating a man-made sound in its territorial defense song. But what about the third lyrebird? Where did it come from? Taylor doesn’t tell us.

She goes on to recount another putative instance of wild birds imitating man-made sounds, but that, too, is apparently due to captivity:

There is only one suggested example of imitation of a man-made sound in a lyrebird’s territorial song — wild or captive — that of the “flute lyrebirds” of the New England Tablelands. This extraordinarily complex song consists of flute-like tone colours.

You can hear five clips of the flute lyrebird at this site; just click the “mp3” links at the bottom of each description. Taylor continues:

How have we humans made sense of this?

A lyrebird chick was raised in captivity in the 1920s. It mimicked the household’s flute player, learning two tunes and an ascending scale. When released back into the wild, his flute-like songs and timbre spread throughout the Tablelands’ lyrebird population — or so the story goes.

I participate in a research group that is mapping the “flute lyrebird” territory and studying the origins of this story. Our recent article was unable to consolidate the conflicting memories and recorded anecdotes of credible witnesses.

Nevertheless, every winter the rugged, misty rainforests of the New England Tablelands resound with flute-like timbres, contrapuntal overlapping scales, and melodic contours (often with a musical competence exceeding what a human flautist could achieve) that are poles apart from the territorial songs of the rest of the species.

Do wild lyrebirds mimic machinery and the like? While I can imagine that in rare circumstances their vocalisations could reflect the human impact on their environment (and there are such anecdotes), there is no known recording of a lyrebird in the wild mimicking man-made mechanical sounds. Nevertheless, belief in such a phenomenon is now so well established on the internet that it even crops up on official sites.

Well, I don’t think the splendor if this phenomenon depends on whether the bird imitates sounds it heard in the wild or in captivity. What’s the difference? The amazing part is that the bird can do it at all! So while Taylor’s article adds a bit to our knowledge of how the lyrebird hears the human sounds, it doesn’t add much to our amazement at the bird’s abilities. What her article does show, however—if she turns out to be right—is that bird songs in a region can change dramatically due not to genetic evolution, but to cultural evolution. (If you’re a “meme” fan, you could say that the flute song was an avian “meme”.) The released “flute-imitataing” bird apparently had such a lovely song that the other birds in the area copied it, and it spread quickly and widely.

At any rate, here’s a newer video, also in the process of going viral, in which a lyrebird supposedly imitates the sounds of a video game (did it ever hear one?).  What do you think?

You can also hear the “video game” song in this clip.