TIL crows, starlings and similar birds only *look* black to us — they’re actually very colorful in ways human eyes are unable to perceive.

@leaverou I don't think that infography makes any sense. We do have a sensibility to green, but we still see colors from 400nm to 800nm. Also, what species of crow is that? I don't know any with white spots and a yellow beak.

Is there any source for that?

Edit: definitely, the curves don't mean anything

@ShnoofleBear @leaverou it's arbitrary really - you can use freq or wave length for scale

@petitmote @leaverou having less types of cone cells means you have more metameres, but I don't think it applies here. chroma range is another matter. and there's brightness range.

@alpacamale @leaverou
In the right sunlight you can see most of these colors (Never seen one this vibrant).
But I'd imagine a camera has the range to pick a lot of it up since the visible spectrum is the typical target.

@mattesilver @leaverou yes, I don't think the curve corresponds to the sensibility of the numan eyes nor the colors of the photography

@leaverou Just today morning i layed in the sun with my dog and a flock of starlings started scavaging the park we were in. The sunlight reflected super colorful on them.

@leaverou wait, birds are tetrachromatic? Cool!

@milla @jawnsy @leaverou

These are the AR glasses I want.

@leaverou
I used to toss peanuts to crows regularly, and they were comfortable approaching me. One day in early winter, an hour or so after sunrise, a crow walked close, in front of me, between me and the sun. I was wearing amber polarized sunglasses, and just for ten seconds or so I saw red and turquoise bars on its wings - one of the most astonishing and beautiful things I remember. I've never been able to duplicate it, and have never found corroborating evidence, but I remember thinking "oh that's how they can tell each other apart"

@leaverou Evidence, if needed, that we do not see the real world - what we experience is an approximate proxy.

Besides - the light rays from an object tend to fan in all directions - we only got a tiny sliver of these rays impinging on our retinas. So we only ever perceive very partially. And only perceive a minuscule fraction of all wavelengths.

Poc

@jastrow

Les commentaires semblent dubitatifs.

@leaverou
I was in a zoo JUST today, where I read a sign stating that blackbirds only seem black to humans, while actually being colorful in the bird world. This sign made me a bit mad by telling me such a thing without explaining why. Now only a few hours later, I stumble upon this. Fedi is amazing!

@petitmote @leaverou

The curves seem to be showing the sensitivity of cone cells in human eyes vs bird eyes. Humans (who aren't color blind or tetrochromats) have cells most sensitive to blue, green, and red, around the wavelengths indicates. The graphic shows that, though not in a super literal way. There are long tails on all those curves in real life. A color like yellow lights up both the green and red receptors, and that's how our brain distinguishes it from pure green or pure red.

I don't know as much about bird vision, but I think the curve is suggesting that they also have cells sensitive to UV light, and that their visible light receptor cells are most sensitive at different wavelengths than ours

There's nothing on the chart that indicates what wavelengths are actually being scattered from "black" bird feathers, but if it's in the gap between our green and red receptors, or if it's in the UV, birds eyes would be more sensitive to it. Though we CAN see some UV at the lower wavelengths if it's really bright, and we can of course see yellow and orange... Birds would just see them more brightly. The picture someone shared in another reply showing what a black bird looks like to a camera in really bright sunlight seems like a pretty good indication of what colors birds might be seeing with their more sensitive receptors at some of these wavelengths - but they are probably seeing them as brighter colors even in dimmer lighting.

https://tech.lgbt/@catraxx/116506023447408575

@leaverou gimme birbs eyes please 🥺

@leaverou starlings are kaleidoscopic

@alpacamale @leaverou
No, because the camera sensors, especially decent ones have a colour filter array to suit both typical RGB displays and the human eye response.

Just out of band IR or UV will create false RGB, some phone cameras will show white or blue for near IR (point TV remote at it) and a UV fly trap will look a quite different colour on phone than by naked eye.

The displays typically have narrow R, G & B at peaks of human response and good camera filters use R, G & B curves.

@ShnoofleBear @leaverou
Sometimes shorter wave (UV) is towards orgin. Or it can be labelled in wavelength, but ordered by frequency, so IR is toward origin,

@raymaccarthy @leaverou Damn. But thanks for the explanation.

@milla @leaverou Magpies you say...?

@alpacamale @leaverou
You need a UV camera and then edit the regular RGB to fake colours and then the mono UV as Blue. The simple way is to use two layers and mess with colour balance hue on the colour one till far blue is black and the mono UV layer till it's only far blue and merge.

You can't ever see what birds or any creature (or Alien) with better colour vision sees, but you can downgrade to what dogs or cattle see.
Some women are a bit tetrachromatic on retina but eye filters it.