Horses are red/green color blind

[motorgypsy]

This is so interesting.

Color vision in horses (Equus caballus): deficiencies identified using a pseudoisochromatic plate test.
Hanggi EB, Ingersoll JF, Waggoner TL.

Equine Research Foundation, Aptos, CA 95001, USA. EquiResF@aol.com

In the past, equine color vision was tested with stimuli composed either of painted cards or photographic slides or through physiological testing using electroretinogram flicker photometry. Some studies produced similar results, but others did not, demonstrating that there was not yet a definitive answer regarding color vision in horses (Equus caballus). In this study, a pseudoisochromatic plate test--which is highly effective in testing color vision both in small children and in adult humans--was used for the first time on a nonhuman animal. Stimuli consisted of different colored dotted circles set against backgrounds of varying dots. The coloration of the circles corresponded to the visual capabilities of different types of color deficiencies (anomalous trichromacy and dichromacy). Four horses were tested on a 2-choice discrimination task. All horses successfully reached criterion for gray circles and demonstration circles. None of the horses were able to discriminate the protan-deutan plate or the individual protan or deutan plates. However, all were able to discriminate the tritan plate. The results suggest that horses are dichromats with color vision capabilities similar to those of humans with red-green color deficiencies.

[Carol Nelson]

Boy, I sure wish they'd use language us lay folks could understand... :roll:

[PattiB]

We had a mare at college that would refuse a red jump of any kind. They said she couldn't see red and it was just a fluck

[PasoVicki]

Boy, I sure wish they'd use language us lay folks could understand...

I think this part is a good summary of the gibberish:

The results suggest that horses are dichromats with color vision capabilities similar to those of humans with red-green color deficiencies.

This site has a simple example of red-green color deficiency:


http://www.toledo-bend.com/colorblind/Ishihara.html

[Minouri]

How many horses were tested? Do they represent all horses and all breeds. Some people are color blind, why can't some horses be?

[motorgypsy]

Good point. I'm sure they'll continue to test more horses but if their test group was composed of multiple breeds they probably considered that their sample was varied enough to be valid.

CarolN - you just skip the gobbledygook and usually somewhere in the article there's a summary that makes sense. I personally think they should have a lot of pictures in their articles!!

[Minouri]

Test results like that always remind me of the rat test I heard about while in college. I forget the name of it. But they were testing rats on how social they were...how outgoing....something like that. They pulled the rats out of this huge cage.

Well, it turns out that if you reach into a huge cage like that....the rats that you can catch....the rats that are right next to the door....ARE the social/confident rats. The fearful ones are hiding in the crowd. So, even though they tested many, their test results were invalid.

I've also seen a young Chinese girl almost diagnosed deaf because she was ignoring both her teacher and the annoying people who kept coming in to test her hearing. I pushed for a Chinese tester...and viola...the child could hear.

Maybe those horses can see those colors...but don't like them? Seems like red would be a color of poisonous animals.

Just tossing ideas out there since I doubt they were able to explain the rules of the game to the horses.

[motorgypsy]

They do a lot better job of standardizing research today. And if evidence turns up that contradicts the original assumption they just keep testing until they either are satisfied that the original theory needs to be revised or that the original one is correct.

My first physics professor told us on the first day of class that HIS first physics professor told THEM on the first day of class to remember ONE THING - THE ATOM CAN NEVER BE SPLIT!! Well the headlines in the newspaper the next day read ATOM IS SPLIT!!! So you never MARRY your theories because they are always subject to revision as you think of better ways to test them.

[Minouri]

I love that one! :)

[Rusel]

Dancer sees red every time I'm late with breakfast.... tested multiple times and always consistant....

Other horses here seem to be the same way....

Maybe they should test more than 4 horses.... or more than 2 different tests..... or test pasos

[motorgypsy]

:lol: :lol: :lol:

[DebJ]

You mean if I wear a red shirt, that Ladybug won't see me when I go out to the pasture to get her??? HHMMM, might try that :lol: ;-)

[motorgypsy]

No chance!! ;-) ;-) I had a friend who was red/green color blind. He accidentally bought a pair of bright red pants because to him they looked brown. So they see them - just not as red or green but as some other color shade of gray perhaps.

[DebJ]

OK, I actually have no trouble getting her in the pasture ;-) , but that is quite interesting about those colors. Wonder how they see all that grass and leaves that they eat? Like what shade would make them so appealing? Or maybe it is just the smell? Interesting.

[motorgypsy]

I'd go with smell. When I offer a treat I always hold it to one nostril first and then to the mouth and they'll take it if it smells good! ;-) ;-)

[DebJ]

LOL Yes, mine definately know when I have treats. Lightningbug even takes her lip and rubs it on my pants pocket where I have them. That is why I don't have any trouble getting either of them in the pasture. It's like "LOOK, here comes mom, FOOD !!! :lol: And they even stand nice and have to take turns sharing them.
They do have a great sense of smell, so that is probably more likely how they chose the stuff to eat and not eat.

[SandyMM]

So... what if you take the test and your computer monitor is actually just way off??? :shock:

[motorgypsy]

Good question but unless you've been playing with magnets or have something burned out in a CRT monitor it won't be off that much. I imagine most people who are color blind find out at a very young age when they can't tell the difference between an apple and a horse apple. :puke :puke