Many birds fluff out their feathers as part of a display – think of cooing pigeons or strutting turkeys. But birds–of–paradise take it much farther than most birds. The males extend specially shaped feathers, lining them up precisely to change the bird’s outline into a new shape. In this section we’ll explore different ways and feathers that some species use to get the job done.
Shape Shifting: and the Birds-of-Paradise
So how do they do it?
How if you’re a bird do you become something else?
The obvious way to change your shape if you’re a bird — and this is what I think most people assume is what’s going on when you see one of these shape shifters do its transformation for the first time — is use your wings.
I mean that’s the thing that – I think our brains look at the birds and we think, oh, they’re going to make some unusual shape.
It’s because they’re lifting out their wings and they’re wrapping it around their head or they’re doing something with their wings.
And in fact some of the birds that are the shape shifting birds-of-paradise, the ones that transforms themselves — mainly the riflebirds — that’s what they use.
But their wings aren’t like normal wings.
All the flight feathers are rounded instead of being pointy like they typically are for flight, so the feathers look different.
And that’s how they make this really nice, kind of perfect oval shape, or ovoid shape.
But the other species, they are using not their wings, so they’re not using an appendage but they’re using a series of feathers that line their bodies, the same kind of feathers that all birds have in terms of where they’re found on the body.
And they’re lining them up into precise ways to create this meta-structure, if you will, that’s a composite of all these little individual parts, all those little individual feathers.
So they’re using those special muscles in the skin, lifting them out precisely, putting them in to the place they need to line up and look like this unusual form.
So it’s easy for us to think about how you might do that with your arms, your appendages.
But it’s really hard for us to think about how you would do that with your feathers.
We don’t have any analog, it would be like trying to figure out, you know, create a Mohawk without hairspray, basically (laughs).
By this you mean using the muscles in the head.
Using the muscles in your hair. That’s right.
Yeah, the same muscles that we use to move our eyebrows around but somehow doing that with something like the hair on top of our head and making an unusual shape out of it.
I mean, you know, it doesn’t make any sense to us.
Maybe to a bird it makes more sense, but that’s pretty amazing.
Shape shifting’s not really a technical term.
Is this strategy of turning into a black oval common in birds or found in any of the other birds?
Certainly there are some other birds that utilize their body parts to modify their shape.
The common one I think that people, at least in North America, are familiar with would be a turkey.
So a male turkey when he’s strutting himself, he fluffs out his feathers and he fans his tail.
And, you know, basically if you’re a bird with feathers and you stick them all out in some ways you’re going to create something that’s blob or oval like, so it’s not too much of a stretch to think that, you know, this can happen.
But no bird that I know of do it quite the way that birds-of-paradise do, where the transition is so extreme and so precise.
And it’s not just the spread tail but it’s a combination of feathers from the tail, the sides, back of the neck that all line up to make a form that looks so un-birdlike when it’s done, and it’s so specialized and has been incorporated in a very precise way.
That level of modification, or that level of shape shifting, I don’t think – hasn’t any precedence in any other birds.
So that black oval, did it just evolve once in birds-of-paradise and that they sort of got it and everybody has a variation on the theme?
It’s possible although it’s not really clear that the, that the desire to have a black oval like shape as the thing that’s the object of affection might have evolved once, meaning that the females have this preference for things that look bigger than the body of the bird, that are black and are highlighted with colors.
But what’s definitely not the same is that the way different species of birds-of-paradise males have evolved to present that oval shape.
So some do it with their wings, some do it with feathers of their sides, of their breast and their flanks that they lift up around their head.
Others do it with a different set of feathers from the breast and flanks they wrap around their body in another orientation.
The superb bird-of-paradise creates its oval shape by using modified feathers on the back of its neck that it lifts around its head.
So even thought they superficially look similar at the level of being black ovoids, they’re fundamentally different in the way that they’ve evolved over time through sexual selectionto be an oval.
One of the things about an oval is that it matters how you look at it.
Once they’ve transformed it’s all about perspective, right? Yeah.
The transformation into this ovoid shape typically happens when the female is in view of the male and she’s showing these signs of either coming and flying and landing right where he’s going to be or he has some expectation that she’s going to arrive.
He’s definitely always presenting and facing her so that she sees the part of the ovoid presentation that has the highlights and the colored feathers or has their proper shape.
And if the female moves the male just has to move with her so that she can always see the part that she’s suppose to see.
Because if you look at any one of these shape shifting birds of paradise from the wrong side it’s not as impressive as it is from the side that the females have selected.
You ask anybody, you can ask a second grader or anybody, an adult to draw a picture ofa bird and you’re basically going to get one of two things.
You’re going to get a line with some wings coming out and pretty much all birds whenthey’re flying they have that wing-bird shape.
And then maybe this kind of like sitting perch bird shape.
But you certainly wouldn’t in your wildest imagination, draw a bird that looks like it’s wearing a ballerina’s tutu or some kind of psychedelic smiley face, right?
I mean, this is outrageous and without precedence and, you know, that’s just cool. How could you not want to know how on earth birds came to use these kinds of shape for courtship display?
End of Transcript
Several kinds of birds–of–paradise transform their bodies into a dark oval shape when they display. Each species uses a different assortment of feathers on the wings, flank, or neck. They use muscles in the skin to move the feathers into position. The black shape serves as a background for showing off a bright patch of iridescent color to the females.
Black Sicklebill: The Thin Blue Line
Yeah, I mean, of course there are many broken off snags throughout this forest, and how do you find the one that the black sicklebill’s displaying on?
Well, the black sicklebill is, I think, is one of the most amazing bird-of paradise displays.
It’s one of the displays in which the bird totally changes his shape.
He completely changes into something kind of otherworldly.
He goes from a movement of more or less a recognizable bird-like form, albeit a pretty extraordinary one with his long d-curved bill and long tail, and these flank feathers sitting out at his side.
And he raises them up around his head in a complete ring, okay, and completely closes off with only his beak sticking through.
He lifts those feather up around his head and makes this kind of amazing black ovoid shape, something very non-birdlike.
And then not only that, he also leans over on his side and bobs up and down.
So he becomes this sort of comet shape thing.
It’s sort of a dark brown black sort of comet shaped object with a little blue ring around the rim.
This ovoid shape is made out of dozens of feathers all along the side of his body, on either side.
And on the tip of each of those feathers it’s tipped with blue, and somehow when he puts all those feathers together and goes horizontal they all line up so perfectly that you get a continuous blue line of feathers.
Whereas if you were just looking at him in normal bird form, all of those feathers would just have blue tips, they wouldn’t make any sense, they wouldn’t line up to make any kind of pattern.
And that’s just kind of the really incredible part of it – the precision of these feather ornaments to make something so unusual and extraordinary.
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Black Sicklebills are elegant, slender birds with long bills and tails. But that all changes when a female comes by. The male transforms into a horizontal comet shape on his display perch. He doesn’t use his wings to do this; he uses flank feathers. The comet shape is accentuated by a narrow blue band of iridescence created when those flank feathers line up precisely.
Superb Bird-of-Paradise: Psychedelic Smiley Face
This is the male suburb bird-of-paradise.
While he might not look all that suburb at first glance, he’s capable of one of the most jaw-dropping transformations which is unrivaled even among the other shape-shifting birds-of-paradise.
People who’ve seen this display have called it everything from a space alien to my personal favorite, a psychedelic smiley face.
But how did he get here?
How does he go from something otherwise birdlike into something so unusual and extremely different?
In order to better understand what’s going on we need to become more familiar with the basic parts of this bird.
The most obvious of course is this delta shaped iridescent breast shield, and that, of course, becomes one of the key features of the ultimate transformation.
The other features that help make this transformation complete, which are a little bit difficult to see here, are the feathers on the back of the neck, or nape.
I call these the cape feathers.
Beyond that, there’s a series of blue iridescent feathers that are on the top of the head, or the crown.
And then there’s another set of feathers that really makes the illusion complete, these special feathers that emanate from the sides of the bill.
So with the delta shaped breast shield, the cape feathers that lie across the back, the crown, and the special feathers along the bill, all of these are going to interact to make this illusion work.
And here’s how it happens.
When he sees a female coming near his display site, one of the first things he does is lift his iridescent breast shield up and extends it out.
He also pushes the iridescent feathers on the top of his head forward so that they’re also visible to the female.
Now here is where the real transformation begins.
He takes those feathers that are lying across his back, the cape feathers, and he rolls them forward so that they form this black cone or ovoid shape that’s framing the breast shield and the crown feathers.
When the cape is pushed forward, he actually lifts his head up so that his bill bisects the blue iridescent feathers of his crown.
So now you have two parts of these crown feathers that have been divided by the bill.
Now here’s where the real illusion takes hold because it’s these little feather tufts that come off the side of the bill that curve around at that point and actually make the crown feathers look more circular, like eye-spots.
So what we have when we’re done is really just an optical illusion of what appears to be eyes and a mouth in this black oval face.
And it’s all the result of this interaction between these specially modified feathers.
Now if we move away from the female’s perspective in the front and take a look at the bird from the side, we can actually see how all these components are working together to create this fantastic transformation.
You get a good look at how the cape feathers are lifted forward from the back of the neck to create this ovoid shape.
And you can clearly see where the tuffs extend off the sides of the bill to create those eye-spots.
So as if the transformation from something birdlike to something so otherworldly wasn’t enough, as he’s bouncing and dancing back and forth along the log, every time she moves he has to move to counter her to maintain the illusion and keep presenting the proper perspective.
So when the female goes to the other side here and stops, this presents a really interesting opportunity for us because we can actually see something that the female never gets to see.
On the backside of the cape there, you can actually see how it’s composed of many different individual highly modified feathers, perfectly orchestrated to create that ovoid cape presentation.
I also like how he’s frozen here, you can actually see him breathing heavily.
He’s trying to hold so still and maintain the illusion, he’s trying to gage what the female’s going to do but he’s actually quite exhausted.
But alas, even the most impressive transformations don’t end successfully and he’s left alone on the log (laughter).
End of Transcript
When you see a Superb Bird–of–Paradise displaying, it doesn’t look like a bird at all. The change is so complete that females just see a jet–black disk with an electric–blue “smiley face” pattern. A close look at the transformation reveals how modified feathers on the head, back, and flank combine in an unexpected way to create a spectacular effect.
Parotia Ballerina Dance
The quintessential parotia display that is the highlight of their courtship repertoire is when they transform from something that looks mostly birdlike into one of these amazing shapes.
And we call this display the “ballerina dance”.
It’s a display that’s at once comical and awe-inspiring.
The male is standing there upright.
And he bows down, he’s just kind of frozen like a plank.
And when he lifts up, this is the real moment of transformation, and he basically becomes a new object.
Where the feathers of the flanks are wrapped around his body and he creates the skirt form that gives it the name “ballerina dance”.
It’s important to keep in mind that this is how we see this display.
But of course, this display isn’t intended for us.
This display evolved through the process of sexual selection by female choice.
And the females are sitting above looking down.
For years after seeing many different versions of the ballerina display from the side, we had always wanted to get cameras in position and see the male closer to the way that she sees him.
It wasn’t until our very last expedition that Tim and I finally had the chance to see the “ballerina dance” from the female’s perspective.
Turn back and forth.
We did this by using our remote camera set up.
And what the female perspective camera revealed was quite surprising.
What from the ground looks like a ballerina dancer, looks totally different from above.
What the female sees is actually more like a wobbling black ovoid.
The skirt, that looks like a skirt from the side actually looks like a disk wrapped around his body.
In fact, we probably wouldn’t have even called it the “ballerina dance” had we seen it from this perspective the first time.
You can’t see the bird’s legs, you can just barely make out the head wires.
Even when the male is doing his waggle you can’t really see the incredible iridescent of the breast shield, except for right when he plunges his head down and it’s lifted up sending a really intense directional color signal to the female above.
So what was really great about this is having the two remote cameras synchronized really helped us understand this incredible moment of transformation even better.
He’s going to do another practice display.
(Laughs) He’s like right in the camera.
End of Transcript
At first, the parotias seem to do a different kind of shape shifting from other birds–of–paradise. They fan their feathers into a kind of skirt and then stutter–step around their court in a display called a “ballerina dance.” But a new camera angle reveals that the display looks entirely different to the females who are judging from above.