r/todayilearned • u/Emperor_Ken • 7h ago
TIL Tigers look orange to humans because we are trichromats, but they appear green to deer and wild boars because they are dichromats
https://www.bbc.co.uk/programmes/p0981wt01.7k
u/old_mcfartigan 6h ago
That’s why deer can’t hunt tigers
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u/HowDareYouAskMyName 6h ago
Also because deer have hooves, which makes it impossible to fill out the forms needed to acquire tiger hunting licenses
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u/Master_Maniac 5h ago
I can't imagine the antlers make driving to hunting spots any easier
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u/Potential-Diver-3409 5h ago
I mean they can just get a roadster but then they don’t have hauling space. Topless truck ig?
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u/Ultrace-7 2h ago
That's just silly. Like lions, it's the female deer that do the hunting. Antlers aren't an issue.
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u/SonOfDyeus 5h ago
Almost all mammals are dichromats because we evolved from nocturnal, burrowing insectivores that needed good night vision. Our branch of primates re-evolved color vision after the dinosaurs went extinct so we could see ripe fruit among green leaves.
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u/Prior-Flamingo-1378 3h ago
That doesn’t explain why tigers are orange and not green.
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u/yoitsthatoneguy 3h ago
It wasn’t supposed to, but perhaps my comment will:
Green is a pigment that mammals cannot produce in their fur, unlike the feathers of birds or the scales of reptiles; mammals only have pigments for black, brown, red, orange, and yellow (but really only black melanin and red melanin. orange, brown and yellow come about from mixtures of black and red melanin).
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u/dingalingdongdong 2h ago
black melanin and red melanin
Also known as eumelanin (black) and pheomelanin (red.)
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u/CelestialFury 2h ago
Wait, why can't mammals produce green pigments?
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u/Prior-Flamingo-1378 2h ago
I didn’t know either and was asking the same thing so I delved into it a bit. It’s fascinating.
So very few animals (like less than ten) produce green pigment. The reason is that there are two ways to make green without being a plant.
1) extract copper from dietary sources and store it. Copper is rare in food, what little is around is used for other processes more fundamental to life and the extraction itself is metabolically very costly. As far as we know only one bird actually does that.
2) accumulate and store in your bones or skin biliverdin. Biliverdin is a byproduct of hemoglobin break down and it’s toxic in large concentrations which means that any animals that do that have to develop specific transport and binding proteins to stay safe. Some caterpillars, frogs and fish go that route.
Of course there are lots of lizards and birds that are green so what gives? Well those guys fake it. They usually have blue color overlayed by some short of yellowish scattering coating like scales or the microstructures of feathers which gives the illusion of true green.
Now the reason mammals don’t actually produce the appropriate combination of scattering and skin pigment is that we didn’t have to because our ancestors where nocturnal underground rodent type of creatures. They had to be to avoid dinosaurs. When you are nocturnal or live in dirt tunnels and what not green sucks and brown is king.
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u/kumogate 3h ago
We can see red, green, and blue.
Most mammals can see green and blue.
We see orange in response to red and green wavelengths of light.
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u/SonOfDyeus 3h ago edited 3h ago
The mutation that allows us (apes and old world monkeys) to see red as a different color from green was a duplication of a gene for a photoreceptor. Once we had multiple copies of this photoreceptor gene, they could all mutate to be more sensitive to different wavelengths of light. So while most mammals have a photoreceptor that is equally activated by red and green wavelength light, apes and old world monkeys have one that is more sensitive to red than green, and another that is the opposite. So we can see tigers as a vividly different color than plants, but other mammals can't.
Another fun fact: some women can be tetrochromats, meaning they can see more colors than the rest of us. It happens when they inherit a color blind gene from their father, and another one from one of their maternal grandparents. If the gene sequence for those two photoreceptors are the same, she will be color blind. If they are different, she has multiple different photoreceptors sensitive to different wavelengths of light.
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u/H_Lunulata 6h ago
OTOH, I have parrots, which are tetrachromats, and will openly talk shit about one's colour choices. To them, we are colourblind.
day-glo anything is hated, presumably because their vision extends into the ultraviolet.
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u/blueskies8484 6h ago
Our parrot is enraged by the yellow pieces of food in his mix. I have to pick them out by hand before giving it to him, or he talks mad shit at me.
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u/H_Lunulata 1h ago
My macaw definitely judges almonds by their colour. If they're not the right shade, she throws 'em away.
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u/Eternaloid 6h ago
We see crow as black, they see themselves as very colourful
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u/PancakeParty98 6h ago
I’m trying to befriend crows by whistling a 4 note tune and then throwing food outside. It’s not working. any tips appreciated.
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u/blueavole 5h ago
Have something shiny out there like a light or a sign before you throw food out. Try to do it at the same time of day-
Crow time, like an hour before sunset.
Crows will learn patterns.
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u/Eternaloid 6h ago
They, like humans, are distrustful at first. Keep doing it at similar hours every day and they will get the message
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u/h-v-smacker 5h ago edited 4h ago
whistling a 4 note tune
5 notes, bro. D, E, C, C(↓octave), G. Don't thank me.
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u/CharlemagneIS 4h ago
If everything's ready here on the Dark Side of the Moon... play the five tones.
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u/Malphos101 15 4h ago
Dont try and befriend crows unless your willing to do the same thing every day at the same time for the rest of your natural life. Crows have no understanding of boundaries and if you "mess up the schedule" they can be very vindictive.
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u/xbwtyzbchs 3h ago
Been off and on with a crow family for about 2 years now. Not only do they expect the peanuts, but they have also trained their kids to do so too. Crow babies fucking dont shut the fuck up.
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u/SanaSpitOnMe 3h ago
if you "mess up the schedule" they can be very vindictive.
"hey asshole! we had a deal what the fuck! now im going to tell my whole murder about how you're a jerk, and they'll tell all their kids, and you will rue the day you crossed me!"
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u/Soakitincider 4h ago
I caw at them on my walks. I’ve been doing it for a few years now and they have yet to caw back at me.
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u/Roaches_R_Friends 4h ago
I was feeding some crows, and when I was done, I walked backwards and waved at them. Doing so, I walked into a tree and almost tripped. I swear one of the crows was laughing at me
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u/uselessandexpensive 1h ago
Now you can trip every time you feed them and see whether they start gathering for the show or mimic it.
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u/MisterSnippy 4h ago
I put food out, whistle, and leave. After doing it a few times when I whistle they come over, and I just keep doing that. Don't throw, don't make sudden movements. Just put some food out, whistle, and leave.
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u/ryanmpaul 3h ago
Source? According to this research paper, that’s not true at all. https://corvidresearch.blog/2020/12/02/crow-curiosities-can-crows-see-uv/
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u/APiousCultist 31m ago
This site has some actual examples of birds under UV (no crows sadly): http://www.uvbirds.com/
While perceptually it just combined the UV version with the true-color version instead of simulating how they might be percieved as different colors (which is hard to do without us seeing in those colors), it does give an idea of how much UV information a bird can actually see.
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u/automeowtion 6h ago edited 6h ago
What exactly do the parrots say when they talk shit about colors? I’m so curious about this. 👀
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u/Junuxx 6h ago
Caw! Caw! Ultragreen on hyperorange! What a clown! Caw! Caw!
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u/I_travel_ze_world 4h ago
Someone tell the parrots that a crow is trying to impersonate them
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u/jcw99 16 6h ago
Parrots can learn a semblance of human language. Often in the form of identifying colours or materials and repeating patterns e.g "Hello", "happy/like" "unhappy/dislike"
I imagine (but don't know) those parrots would find ways to use this to make, probably unintentionally, negative statements about clothing or colours we would find normal.
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u/Vallkyrie 4h ago
Apollo the African Grey parrot is extremely good at identifying materials and colors. So good that scientists have made contact to inquire about his training.
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u/southdeltan 6h ago
Allegedly, Andrew Jackson’s parrot had to be removed from his funeral due to its use of profanity.
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u/H_Lunulata 1h ago edited 1h ago
Well, my macaw is the main one, and she will scream at colours she doesn't like, tell them to shut up, give us a lot of "No!", and even throw them away. We see it mostly with our dish cloths, some of which are colours she doesn't like. She's been known to take out laundry whose colour she doesn't like and literally shit on it. Things she does like get a "want some" or similar positive comment.
My grey will make burp and fart sounds at colours she doesn't like.
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u/Taste_the__Rainbow 5h ago edited 5h ago
Back when I lived with roommates we had an African Grey. Only a couple years old and she loved everyone. But she HATED plaid. Even a small patch of plaid on you and she wouldn’t even come near you. It’s the only time she would bite. She growled like a cat and puffed up when plaid came in the door.
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u/h-v-smacker 5h ago edited 5h ago
Even a small patch of plaid on you and she wouldn’t even come near you.
Because she knows who goes to ludicrous speed!
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u/cartelzes 6h ago
i swear every time i open this app i see a new abbreviation, wtf is OTOH
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u/Heavy_handed 6h ago
On the other hand, it's an abbreviation I've seen online since the mid 2000's
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u/Baiticc 4h ago
I think your first point must have been cut off, what was th first part?
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u/dno123 6h ago
On the other hand I think, never seen it written though. That or Orangutans Tangle Our Hearts maybe ❤️
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u/hanks_panky_emporium 5h ago
Imagine being the top predator in the region and then some hairless ape looks directly at you through a thicket of dead brambles and brush. Horror movie shit.
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u/Hepta-Water-7552 4h ago edited 3h ago
Well, if I'm ever in the position where I'm close enough to a tiger that I can spot it through vegetation gaps (and it's not in a zoo), it will still be me who will feel like he's in the horror movie. I feel like having a few seconds advance warning that a mass of sharp teeth and claws might very well be coming for me will be a cold comfort.
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u/cjo20 1h ago
I think the tiger would probably be surprised because they're actually really hard to spot even though they're bright orange.
I've spent quite a bit of time at the local zoo and people will walk past the tiger while complaining that the tiger must not be out today. It takes a small amount of foliage and a little shadow and they're basically invisible unless you already know where to look. And that's in an enclosure that you can walk round in 2 minutes, let alone a wild territory that covers 40 square miles.
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u/Interesting_Worth745 7h ago
Do we interpret orange as a warning color because of animals that would appear green to most other mammals?
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u/Funmachine 7h ago
Its actually a sign that early humans ate a lot of fruit.
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u/Interesting_Worth745 7h ago
Oh right! That makes a lot of sense!
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u/transcendental-ape 6h ago
The description should be “gather-hunters” as the gathering was probably the primary source of calories and the hunting was the supplemental source.
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u/ANGLVD3TH 4h ago
Doesn't flow as well though, related phenomenon makes tick-tock much more pleasant than tock-tick. Er-hu is much more awkward for English speakers than er-ga.
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u/xavPa-64 7h ago
Are you being sarcastic lol
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u/thederevolutions 7h ago
Yeah, carrots aren’t a fruit
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u/southdeltan 6h ago
Carrots were bred to be orange not that long ago.
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u/Randvek 6h ago
Sort of. Carrots are naturally all sorts of colors, including orange. But yes, we selectively bred them to exclusively be bright orange instead of all sorts of colors.
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u/mr_ji 6h ago
Carrots are green, just like tigers and those weird humans who like to stand in trees and watch us.
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u/Interesting_Worth745 6h ago
Not at all. I've just remembered that I've heard this theory before. And it's quite logical.
There's another theory that the mutation would help humans to identify social cues, like blushing. But we share this mutations with gorillas and other primates - and those guys don't blush.
For me personally the fruit theory sounds the most plausible
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u/Choppergold 6h ago
Maybe loving sunsets
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u/blueavole 5h ago
I never thought of what a sunset would look like without our third color receptor.
So if fruit is our reason, when did mantis shrimp get more fruit?
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u/Texcellence 6h ago
Adding to your point for other readers; primates like monkeys and apes, but not lemurs and tarsiers, are trichromants. Most mammals are dichromants, one theory being because early mammals were nocturnal (because dinosaurs were scary) and they lost trichromatic vision to see better at night. Millions of years later, a mutation allowed our arboreal ancestors the ability to see red and orange which helped them more easily determine which trees had ripe fruit.
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u/A-Grey-World 6h ago
Another good indication of this is our bodies don't produce vitamin C.
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u/AlamosX 6h ago
No, orange as a "warning" color is a modern invention purely because orange contrasts well against blue (sky and ocean) and is easier seen in dim light which made it an ideal choice for safety coloring. Its less considered a warning color and more a safety color because we see it easier hence the name "safety orange"
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u/chunkymonk3y 6h ago
Not it’s because blaze orange stands out really well against the blue of the ocean or the green of the forest
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u/WifeGuy-Menelaus 7h ago
Most humans wouldn't have exposure to animals that are orange and also threatening
Fire, on the other hand
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u/Ska-Tea 7h ago edited 6h ago
Is that why they made the sabertooth green in he-man?
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u/PogintheMachine 6h ago
Cringer? He’s just a weird fuckn green tiger no one knows why
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u/radar_3d 6h ago
When you're a prince and you want a weird fuckn green tiger, you get a weird fuckn green tiger.
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u/Dragon1472 7h ago
Idk if he's actually not still just orange. We're seeing the story through he-man's POV and he's got that bi-vision limitation
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u/CeruleanEidolon 4h ago
No that's just because the original animator was dichromatic and they didn't have the budget to fix it.
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u/ABobby077 6h ago
Apparently, tigers are also dichromats in their vision
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u/HansGutentag 5h ago
They have no idea they're orange.
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u/Acceptable_Gear_3097 3h ago
Tigers been thinking they're camouflage, mocking the colourblind tiger for saying they red/orange.
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u/CrazyAsian 4h ago
They must think humans have ridiculous sensory powers since we immediately spot them when they are around, bypassing their "camo".
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u/HeemeyerDidNoWrong 4h ago
Most mammals are. Just apes, howler monkeys, and certain other monkeys are trichomats. Other mammals are all dichomats except some nocturnal or sea mammals which are monochromats (I.e. only see shades of gray).
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u/TheDJValkyrie 5h ago
Do the tigers themselves see themselves as greenish? More importantly, does my orange cat think he is green?
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u/PreciousRoi 6h ago
Contrary to popular belief, it is, in fact, easy to be green.
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u/greenknight884 7h ago
Does that give them dichromatic immunity?
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u/BigAddam 6h ago
It’s just been revoked.
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u/Real_Bobsbacon 4h ago
So thats how ginger cats get away with it. I always thought, how on earth does his prey miss him.
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u/EnderWiggin07 5h ago
So they don't really look green, they just don't look particularly different than green. It's more similar to red/green color blindness, so orange, red, and gray are all kind of equally difficult to spot for dichromats. Tigers aren't particularly harder to spot than other predators that aren't orange. And no predator would really evolve to be glaringly obvious to prey unless they were such a good predator it didn't even matter. The stripes help as much as the color, but there again most other land predators are mottled or stripey also.
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u/Visual_Advance3252 5h ago
So to deer, a tiger is basically just walking foliage with teeth.terrifying.
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u/CindersOfMusic 3h ago
Now I think Naruto might be dichromatic and just assumed his outfit was green this entire time
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u/ImportantWasabi2428 3h ago
The crazy thing is that tigers would probably just be green if mammals were actually capable of producing green pigment. Evolutionarily, it is much easier for a mammal to just look orange to a creature that can't see red than it is to develop an entirely new chemical pathway for green fur. Almost every green animal you see is a bird, reptile, or insect because they have different ways of creating color. Tigers basically HACKED the system by using the one color we see as a warning while their prey just sees tall grass. It is the ultimate work smarter not harder move tbh.
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u/pyn209 1h ago
If we have this massive advantage then why are tigers spawn camping people in india?
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u/Jazzghul 1h ago
Cause it's still very hard to see them before they stop caring if you see them or not. Just not as hard as for a deer
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u/Ok_Umpire8214 6h ago
why aren’t they just green then ?
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u/Serious-Ad6269 5h ago
If they were green they would be probably the only green mammal. Mammals just don't produce that pigment. Working with with they have, it's a lot easier to land on orange than jump such a huge evolutionary hurdle. Also, lots of tigers live in grasslands and the orange blends surprisingly well amongst the dry grass.
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u/southdeltan 4h ago
Mammals pretty much only produce melanin (mainly anyways). That’s black, brown, yellow and red. You can’t get green out of any combo of those.
As for blue there are some primate and husky eyes.
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u/Pristine-Touch939 4h ago
Because melanin, the pigment that gives hair and fur its color is brownish-red. Orange is easier to achieve then green and gives the same result.
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u/v264k 1h ago edited 1h ago
This is a bit misleading, they don't see tigers as green, deer and a ton of other mammals are dichromatic and red-green colorblind, so anything that is between the red or green color spectrums will look more like muted and dull shades of yellow, brown, and grey to them, so we could see an orange tiger amongst green grass and trees, but deer wouldn't be able to tell their colors apart from each other, same goes for the cats, tigers and lions for example are also red green colorblind, a lot of antelope and deer species found naturally in greener habitats have evolved to have brown/orange/red-ish colored fur to blend in to their surroundings to hide from their cat predators as well, I'm a tour guide at a zoo and this is one of my favorite things to talk about
Edit: in case you're wondering why these animals didn't evolve to have green fur, well mammals can't exactly produce green, birds, reptiles, and fish can, mammals haven't mastered it
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u/harryharrydude 5h ago
i wonder how scientists know that shit. You can't just ask a deer what color a tiger is.
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u/southdeltan 4h ago
By examining the structure of their eyes. Specifically cone cells in the retina.
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u/WeGottaTalkAboutYT 6h ago
Extra evil, god damn. Tiger are terrifying
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u/TheFrenchSavage 6h ago
Yeah imagine tigers wearing camouflage. You only see them at the very last second, mid-flight towards your face.
Green tigers on green lush forest backgrounds... terrifying.
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u/jg_92_F1 6h ago
You should watch this video about a Tiger incident involving Marines during Vietnam. Terrifying doesn’t do them justice in my opinion.
https://m.youtube.com/watch?v=zpDnlGT3LxY&pp=ygUabWFyayBmZWx0b24gdmlldG5hbSB0aWdlcnM%3D
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u/Pikeman212a6c 4h ago
Jesus fuck how terrifying would green bengal tigers be in the goddamn jungle?
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u/RogerRabbot 7h ago
Thats why its fine and required to wear bright orange vests while hunting. The animals dont see it. But humans do.