Sound

We think of Birds-of-Paradise as these visual, visually amazing creatures, but they use sounds.

It’s a jungle out there. When most people think of Birds-of-Paradise or look at pictures of them or video, they’re not thinking about them as being interesting acoustically.

But yet, when you step back and you bother to pay attention to sounds of Birds-of-Paradise, you realize that the kinds of sounds that the males make in courtship, or prior to courtship, are nearly as phenomenal as the way that they look and behave.

This usually is something that begins as a long-distance way of attracting females to the display site, so males have a vocalization – I always think of it as their primary vocalization or their main territorial vocalization or their main advertisement vocalization.

And that’s the one that we use even as researchers or scientists or birders to locate them.

It’s the most conspicuous thing that they do, and that’s by design.

That’s how the females find them as well.

Then in the process of courtship display, there’s a whole range of other sounds that are also given but they’re much less conspicuous, much less commonly heard by us.

Sometimes these are the same sounds but much more commonly they’re not, they’re a totally different set.

Just like all thirty-nine species look distinct, they do all sound distinct.

Now some of the ones that are more closely related that also look more similar, they also sound more similar.

But when you find two species that look extremely different, like a lot of Birds-of-Paradise do from one another, they actually sound as extremely different as they look.

Even though there’s a huge amount of diversity in the types of sounds Birds-of-Paradise make, I would say most people still think of them as being these more crow-like “caw caw caw” kind of sounds. And no doubt, a lot of species do make a plain, not-that-interesting, sounding kind of crow-like, squawk. Parotia’s do that, a handful of other things do that.

But, that being said, the ones that do have interesting sounds, they sound nothing at all like even a bird.

In fact, many of them don’t even sound like things made by a living organism. They sound like a sound that would be from a human machine.

Several good examples come to my mind as being the classic or the best examples of those extreme sounds of Birds-of-Paradise.

The Brown Sicklebill, in particular, makes this very non-bird-like machine gun sound.

Another one of the greatest sounds, is the male King-of-Saxony.

It gives this very unnatural sound that’s just unlike anything you’ve heard before, certainly coming out of the mouth of a bird.

Then there are a number of species that are kind of reminiscent of a bird-like sound.

Some of these would be the Curl-crested Manucode, which in my mind often sounds a little bit like a UFO landing.

And then things like the Magnificent Riflebird, which has a nice musical quality to it. Even though it’s called the riflebird, it doesn’t sound like a gun.

A handful of species have very conspicuous non-vocal sounds that they make, usually in the context of close proximity display to a female.

The best examples of that are the riflebirds.

All three species, when they lift up their wings and they’re moving them back and forth, and the males are usually hiding their head behind their wing.

All three of them have this sound that sounds like some kind of rustling fabric or paper.

Swoosh, swoosh, back and forth, that moves with the wings and that’s actually being produced by the wings themselves, that’s not a vocal sound.

The Superb Bird-of-Paradise is another really great example where during the main display there’s this snapping sound.

He’s doing something with his wings and it looks like with his tail where he’s moving them out quickly, creating like a whip-like “snap”.

I think the thing that I find the most intriguing or interesting about sounds of Bird-of-Paradise is that for literally centuries, people have been so focused on the way that they look, and that’s obviously for good reason – they’re pretty awesome, pretty extraordinary.

But sound is just another extreme thing, just like the colors and the behaviors, in that they’ve evolved as much diversity in the way that they use sound for courtship and for attracting females, as any other kind of ornament that Birds-of-Paradise have. And that’s what really makes the sound special in Birds-of-Paradise.

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He sounds pretty close.

Out of all the birds-of-paradise, one of the most haunting and intriguing vocalizations comes from the curl-crested manucode.

This species is only found on a few islands just off the far eastern tip of the island of New Guinea.
We had the opportunity to see them and Tim photographed them on an exhibition to Ferguson Island in 2005.

And even though we heard their incredible vocalizations back then, we never had a chance to film the behavior until our very last expedition in 2011.

These manucodes are not as sexually dimorphic as the other birds-of-paradise.
The males and the females look the same.

They travel around in pairs and they seem to maintain a territory together, and they are vocalizing both to stay in contact with each other – the male and the female – but also to defend their territory from other pairs.

The reason the curl-crested manucode can make these incredible sounds is because they have a hidden feature under their skin, this really modified part of their anatomy, this elongated windpipe or their trachea.

In most birds the trachea is just this straight tube that goes from the mouth into the lungs. But on the curl-crested manucode, where it’s extremely long and highly modified it comes from it’s mouth, but instead of going straight through to its lungs actually continues between the skin and the muscle and curls all the way around the length of its torso and loops back up.

In some cases it even coils around the abdomen before coming back up and entering into the body to go to the lungs at the base of the neck.

You’ll notice that just before he vocalizes he kind of rears back.

You can see the neck filling with air and that’s that trachea filling up.
And then as they vocalize they kind of lift their head up and roll forward a little bit and their wings kind of spread over their back, and their body lifts up and lunges.

So the curl-crested manucode, they’re not the most extravagantly plumed of the birds-of-paradise but never-the-less is one of the most extraordinary out of the thirty-nine for the way that it sounds.

Move down to the back.
I got him once, though.
Did you get that one? Yeah!

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King-of-saxony birds-of-paradise are species that live in the high elevation cloud forest.

The sound that they make is actually one of the defining features of this habitat.

If you had to guess what this sound was when you first heard it, I don’t think most people would have bird come to mind.

It sounds like something from another planet.

So the territorial vocalization of the male king-of-saxony is a way of communicating to neighboring males that this is my territory, but also serves as an advertisement to females.

Males typically have one snag or exposed branch above their territory where they’ll sit and call nearly all day long.

When a male sees or knows a female’s around he’ll dive down and fly directly into the forest below and usually go directly to the vine that he uses for courtship display.

He often lands there and gives the same territorial or advertisement vocalization calling to try to attract the female to where he is inside the forest.

There’s a lot of variation in the sounds, especially in the territorial advertisement sounds that the king-of –saxony makes.

But one thing that is consistent is this element of building, where it starts off small and then it builds up to this crescendo with increasing intensity and whistling and buzzing and churring all going on at the same time.

You can even see his throat pulsing and moving as he’s making that sound and his mouth
is wide open.

And when you’re up close like we were when we made these recordings, you can really hear
the sound of lots of things you can’t hear when he’s high in the canopy.

This is the beginning of the courtship display where he starts getting excited and he starts bouncing.

There’s no female here, this is just a practice display but you can see the basic components – he’s bouncing up and down, he starts making this really incredible buzzing sound, he inflates himself up and then reaches this crescendo, synchronize at the climax with the visual movement of the head wires as they go forward.

That’s really incredible.

The voice of the king-of-saxony is like a lot of things about the birds-of-paradise.

You can’t really imagine that it really exists until you see it or hear it.

And when you do see it or hear it you still can’t believe that it exists.

But it’s one of these incredible things that you won’t forget once you do.

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This is a male magnificent riflebird.

He’s got this incredibly clear, powerful whistle that just carries great distances through the dense lowland forest where he lives.

And here’s a male black sicklebill.

He also makes an incredibly powerful sound from his courtship display territory.

In both cases the males are using these calls to advertise to females a great distance that this is their courtship display area.

But they’re also announcing their presence to other males who have territories nearby.

And clearly, as you can see, both of these sounds are vocal, meaning that they are created with the same vocal apparatus that all birds use to produce sound – their bill, their trachea, their syrinx.

Another thing these two species have in common is that they both produce nonvocal sounds, that is they make sounds with parts of their body that we don’t typically associate with sound production.

Let’s check out how they do it.

This is the male black sicklebill again.

His nonvocal sound is a knocking, it sounds like a distant machine gun.

From this view you can tell he’s not making that sound with his mouth.

His bill is closed.

But it’s a little bit hard to tell where it’s coming from and what’s going on.

Fortunately on this day we had two cameras recording at the same time.

What you can see from this other camera is that as he does this display and he comes upright, he actually opens his wings across his back.

It’s a little hard to see what’s going on there, but those are his wings and those primary feathers are spread across the back and as he lunges forward he closes those wings across his back and somewhere there either between the feathers rubbing against themselves or perhaps against the base of the tail, that’s where he’s creating that nonvocal sound.

So now we’re looking at the male magnificent riflebird.

He makes his nonvocal sound in courtship display somewhat like the black sicklebill, but he does it in a very different way.

As you can see, he’s opening his wings up and he’s moving his head from side to side.

And when he’s doing that he’s moving his wings.

That sound that you hear is being produced by the opening and closing of the wings.

It sounds like a pronounced rustling.

Another really cool aspect of this nonvocal sound is how directional it seems to be.

Notice when he turns around the sound gets louder.

And that’s because he’s directing that sound towards the female, and in this case it also happens to be directed towards our microphone, so it’s picking up the sound as well.

Although there’s never been any good research on this, it’s possible that the shape of his wings would have something to do with projecting that sound in the direction of where the female is; almost like it’s an amplifier or like a megaphone.

What’s cool is, is when we think back to the black sicklebill, he also seems to have this curved kind of megaphone aspect to his courtship display.

And we know that the female, just like on the magnificent riflebird, she also sits right in front of the male when he makes his knocking sound.

So it’s possible that both of these species have this directional element, directing that nonvocal sound right where they want it to be, where the female is when she’s watching their courtship displays.

Clearly both these species have extraordinary vocal sounds.

But it’s these nonvocal sounds that they make in their displays that really sets them apart from other birds-of-paradise.

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