In nature, none more black than the birds of paradise (plus a relative)

January 10, 2018 12:47 PM

The mating dance of the male superb bird of paradise is like nothing else on Earth. To win the affection of a female, he forms a sort of satellite dish with his wings, displaying dots and a stunning band of blue against a deep black background, and hops around a female. He and his relative don't only share a unique dance, but unique feathers that absorb light, as described in an article recently published in Nature Communications. In fact, as the feathers structurally absorbs up to 99.95% of directly incident light, it's almost as black than Vantablack with 99.965% light absorption (previously), and blacker than the more commercial 'spray-on' form of Vantablack, which only absorbs 99.8 percent of ultraviolet, visible, and infrared light. [via Wired]

The next blackest black in nature is snake velvet black (article on Nature: Scientific Reports) of the West African Gaboon viper (Bitis rhinoceros), but this, a subspecies of the largest of vipers, has small sections of deep black that reflects only 4.0– 58.0% (median: 10.8%) of light, depending on the wavelength.

posted by filthy light thief (30 comments total)

That is so friggin' cool... it's amazing that we're only just now getting slightly better at stuff than nature already has been forever.
posted by Grither at 12:53 PM on January 10, 2018

Man, that's really cool! I bet that's something that makes the brilliant blue of the iridescence contrast that much brighter--smart, if you think about it, controlling the background of your display patch.

Did you know that blue is usually a structural coloration in birds, by the way? It's not a pigment, which is why it never pops up in mammals--it's an artifact of the way the feather is constructed. It sounds like the deep black is similar, which means it's a neat trick of the bird: not a drop of pigment, and yet such a gorgeous and utterly recognizable color. Beautiful.
posted by sciatrix at 12:57 PM on January 10, 2018 [10 favorites]

Following sciatrix's comment: How Animals Hacked The Rainbow And Got Stumped On Blue

a deeper dive in these links

https://en.wikipedia.org/wiki/Structural_coloration
https://www.the-scientist.com/?articles.view/articleNo/34200/title/Color-from-Structure/
http://pubs.acs.org/doi/pdf/10.1021/acscentsci.5b00272
https://www.smithsonianmag.com/...intense-natural-color-30070457/
posted by lalochezia at 1:03 PM on January 10, 2018 [5 favorites]

So what happens to the photons? Do they just keep bouncin' around inside the feathers?
posted by clawsoon at 1:04 PM on January 10, 2018

Eponysterical, of course.
posted by clawsoon at 1:05 PM on January 10, 2018 [12 favorites]

> So what happens to the photons? Do they just keep bouncin' around inside the feathers?

You could call it that, but it's typically referred to as Heat.
posted by I-Write-Essays at 1:07 PM on January 10, 2018 [7 favorites]

Did you know that blue is usually a structural coloration in birds, by the way? It's not a pigment, which is why it never pops up in mammals

MANDRILL BEGS TO DIFFER
posted by Sys Rq at 1:12 PM on January 10, 2018 [6 favorites]

blue is usually a structural color... which is why it never pops up in mammals
ahem.
On preview, Sys Rq beat me to it. But here is a paper for your troubles. (It's partly structural in Mandrills, too).
posted by agentofselection at 1:14 PM on January 10, 2018 [2 favorites]

Did you know that blue is usually a structural coloration in birds, by the way?

Why yes, yes I did ;) (self link to previous post on structural blue)

It's structural in snakes, beetles, birds and blueberries!

But on this point - then are all colors on the bird of paradises' (birds of paradise's?) wings structural colors? NEAT!
posted by filthy light thief at 1:15 PM on January 10, 2018 [4 favorites]

dammit, I forgot primates! And there's the case of the vervet monkey's splendid testicles, too--that link is exactly as work safe as you think it is.

Give me a minute, I'll find out what's up with some of the weirder mandrills and macaques.
posted by sciatrix at 1:15 PM on January 10, 2018 [3 favorites]

Aha, or I can rely on MeFi doing it for me. :) Awesome, the collagen fiber thing is really cool!
posted by sciatrix at 1:17 PM on January 10, 2018

You could call it that, but it's typically referred to as Heat.

But that's what happens with pigments, innit? In this structural coloration stuff, it sounds like the photons are never getting absorbed, only reflected in magical ways.
posted by clawsoon at 1:20 PM on January 10, 2018

vervet monkey's splendid testicles

I love animals and watch a lot of nature documentaries and somehow this still took me by surprise. I wasn't expecting them to be so, well, splendid!
posted by Kutsuwamushi at 1:38 PM on January 10, 2018 [5 favorites]

How much more black could it be? And the answer is, 0.015%. 0.015% more black.
posted by biogeo at 1:43 PM on January 10, 2018 [20 favorites]

But that's what happens with pigments, innit? In this structural coloration stuff, it sounds like the photons are never getting absorbed, only reflected in magical ways.

I think it would be more accurate to say that in pigments, photons of certain wavelengths are absorbed by electrons in molecular bonds which are capable of absorbing the energy they carry, while in structural color, photons of certain wavelengths are subjected to interference due to refracting off of a material that has a surface structure with texture on the same spatial scale as the photons' wavelength.

Structural color is basically the effect you get when you look at light reflected off of a CD. (For younger Mefites, a CD is a special type of coffee coaster we used to receive for free from a company called America Online.)
posted by biogeo at 1:52 PM on January 10, 2018 [22 favorites]

All that effort for naught :(

If birds are descended from dinosaurs, does that mean dinosaurs had elaborate mating rituals? Can you even imagine?
posted by AFABulous at 3:42 PM on January 10, 2018 [4 favorites]

That's a really great point, AFABulous; we have bunches of fossilized dinosaur footprints, and if they did have the kind of mating rituals you suggest, there ought to be a fair number of really churned up dance floor palimpsests out there too, and I wouldn't be too surprised if somebody's seen them, but didn't recognize them for what they were because they hadn't heard your wonderful idea.
posted by jamjam at 4:09 PM on January 10, 2018 [3 favorites]

"Vervet Monkey's Splendid Testicles"

Metafilter sock puppet nickname?
Next band name?
1970s porn film?
Unpublished Roald Dahl short story?

So many possibilities...
posted by Multicellular Exothermic at 4:36 PM on January 10, 2018 [3 favorites]

Crazy mating rituals are everywhere in nature, of course dinosaurs had crazy mating rituals.

The real fun is trying to imagine what kind of crazy mating ritual would create the selective pressure to explain a T-rex's silly undersized arms.
posted by biogeo at 4:43 PM on January 10, 2018 [2 favorites]

The real fun is trying to imagine what kind of crazy mating ritual would create the selective pressure to explain a T-rex's silly undersized arms.

Swiping right on cloa.ca
posted by maxwelton at 5:08 PM on January 10, 2018 [7 favorites]

I like to imagine T. rex displaying like modern grackles in a competition to see who can stretch his head highest, except while also flapping tiny feathered little wings about.

Bonus if they also hunch over and open their massive mouths and stalk forwards all floofed up to intimidate their opponents.
posted by sciatrix at 5:12 PM on January 10, 2018 [2 favorites]

Obligatory none more black comment.
posted by Annika Cicada at 5:36 PM on January 10, 2018 [1 favorite]

Oh, additional fun thing about structural color. In many bird species, black feathers aren't even actually black, they're ultraviolet, a color most birds can see just fine. Ultraviolet pigments are rare, so this is also achieved with structural color.

Many dark, drab-colored birds actually have bright plumage patterns in the ultraviolet, so to each other they're extremely eye-catching.
posted by biogeo at 5:48 PM on January 10, 2018 [6 favorites]

Oh my god, imagine a big group of T-rexes doing this.
posted by biogeo at 5:51 PM on January 10, 2018

Yes! The grackles I mentioned have great big ultraviolet patches on their throats, a thing I had suspected but made me literally fistpump in joy when I noticed a dead specimen whose feather pattern showed off the throat patch after, you know, a being a bit motheaten at a museum a few years ago.
posted by sciatrix at 5:54 PM on January 10, 2018 [1 favorite]

*... nice strutting, there... good housekeeping skills... that's one mad dance move --* HOLY CRAP!!

That was... intense. Reminds me of the courtship rituals of the peacock spider (be advised, this does not always end well. Spiders, ya know).
posted by TrishaU at 6:57 PM on January 10, 2018

If birds are descended from dinosaurs, does that mean dinosaurs had elaborate mating rituals? Can you even imagine?

Yes. Yes I can.
Theropod courtship: large scale physical evidence of display arenas and avian-like scrape ceremony behaviour by Cretaceous dinosaurs
Nature Scientific Reports 6, Article number: 18952 (2016)
doi:10.1038/srep18952
posted by Trinity-Gehenna at 1:49 AM on January 11, 2018 [8 favorites]

AFABulous: If birds are descended from dinosaurs, does that mean dinosaurs had elaborate mating rituals? Can you even imagine?

Trinity-Gehenna: Yes. Yes I can.

This is why I come to MetaFilter, to have hypothetical questions answered with SCIENCE!

Large scrapes, up to 2 m in diameter, occur abundantly at several Cretaceous sites in Colorado. They constitute a previously unknown category of large dinosaurian trace fossil, inferred to fill gaps in our understanding of early phases in the breeding cycle of theropods. The trace makers were probably lekking species that were seasonally active at large display arena sites. Such scrapes indicate stereotypical avian behaviour hitherto unknown among Cretaceous theropods, and most likely associated with terrirorial activity in the breeding season. The scrapes most probably occur near nesting colonies, as yet unknown or no longer preserved in the immediate study areas. Thus, they provide clues to paleoenvironments where such nesting sites occurred.

Trace fossils are fascinating, particularly because they require some fascinating speculation, drawing connections between modern activities of potentially similar animals.
posted by filthy light thief at 7:14 AM on January 11, 2018 [3 favorites]

This thread is not complete without a bird of paradise cosplay.
posted by plinth at 7:15 AM on January 11, 2018 [4 favorites]

FWIW, a cheap way to demonstrate "ultrablack" is to take a stack of nice new double-edge razor blades (or utility knife blades, but not glass scraper blades, they don't sit against each other tightly enough), and then play with the stack—sometimes they need to be at a very slight angle—such that the face consisting of the blades' sharp edges suddenly becomes very black. The blades need to be very new and very sharp, so that they're basically a mirror finish. Basically they form a sort of "light trap" where photons enter, but they never leave—they just bounce around until absorbed.

I've never looked at this in a photometer but I suspect it probably emits in the infrared. It works fairly well as a "beam dump" for low to medium power laser applications, though, if you encase it in a small box.
posted by Kadin2048 at 8:06 AM on January 11, 2018 [3 favorites]