colors

[A<3L]

Can squirrels see color or are they color blind?

[Nancy in New York]

Can squirrels see color or are they color blind?

The one who can answer this is astra, she actually has some interesting articles on this topic.

[A<3L]

Thank you!

[LeilaNami]

Hi! Squirrels have dichromatic vision. They can see color but they are red-green color blind.

[astra]

The one who can answer this is astra, she actually has some interesting articles on this topic.

Like Leila said, supposedly, squirrels are red-green colour blind.
What this means, in very simple terms:

There are three primary colours that cannot be created by mixing other colours. That's why they are primary: red, yellow and blue.

The remaining colours result from various mixes of the primary colours.

That means that pretty much each color has a little bit of red, yellow and blue.
But since squirrels cannot see red, then, those colours that have red mixed in them look differently.
The same with green - whatever colours have some green mixed in them will look differently to the squirrel.
Thus, if you think of it, the rainbow becomes a combination of blues, yellows, olive-type of colors (more yellow or more greyish) and greys.

This site shows what color-blind people see: http://www.colourblindawareness.org/colour-blindness/

Also, I said "supposedly" b/c all the info I have come across refers to rats and mice, and squirrels are bunched with them as rodents.

But even though squirrels may not see red, pinks, oranges and other such colors, their "color" world is still quite rich, because it is not so much the colour that adds variety, but the contrast.
I remember reading that animals, including rodents, are good at perceiving different lightness or darkness of colours.
So, the more contrast in a given pattern - the more fun it is for them to see

Another interesting detail - it is believed that ground squirrels can see colour like we do (or almost like we do).
I find this rather surprising b/c ground squirrels spend so much time underground and mostly in deserty like places where there may not necessarily be very colourful vegetation. (so, why would they need to see colour ? but maybe, they need to be aware of various desert insect species? - just wondering. I am all happy that at least gr. squirrels can see full rainbow, but still puzzled - why are tree sqs different?

So, I find it interesting that while tree squirrels are (or believed to be) red-green colour blind, ground squirrels are "full-colour" creatures.

That gives me some glimmer of hope that, perhaps, in this one respect tree squirrels are different from rats and do see full rainbow.

And one more thing to remember: these conclusions are based on the comparison of colour-receptors, and - again, in simple terms - rats and mice do not have enough of colour receptors like people do.
Scientists created various experiments based on this knowledge that seem to confirm the hypothesis that rats and mice are red-green colour blind.
But last couple of decades have been showing that relying on comparative studies between animals and humans may not always produce accurate results. (in other words, perhaps, there are some other mechanisms that regular colour perceptions in animals that are different from humans').
But this is all just speculation and cannot be proved.

Hope this helps

[LeilaNami]

Like Leila said, supposedly, squirrels are red-green colour blind.
What this means, in very simple terms:

There are three primary colours that cannot be created by mixing other colours. That's why they are primary: red, yellow and blue.

The remaining colours result from various mixes of the primary colours.

That means that pretty much each color has a little bit of red, yellow and blue.
But since squirrels cannot see red, then, those colours that have red mixed in them look differently.
The same with green - whatever colours have some green mixed in them will look differently to the squirrel.
Thus, if you think of it, the rainbow becomes a combination of blues, yellows, olive-type of colors (more yellow or more greyish) and greys.

This site shows what color-blind people see: http://www.colourblindawareness.org/colour-blindness/

Also, I said "supposedly" b/c all the info I have come across refers to rats and mice, and squirrels are bunched with them as rodents.

But even though squirrels may not see red, pinks, oranges and other such colors, their "color" world is still quite rich, because it is not so much the colour that adds variety, but the contrast.
I remember reading that animals, including rodents, are good at perceiving different lightness or darkness of colours.
So, the more contrast in a given pattern - the more fun it is for them to see

Another interesting detail - it is believed that ground squirrels can see colour like we do (or almost like we do).
I find this rather surprising b/c ground squirrels spend so much time underground and mostly in deserty like places where there may not necessarily be very colourful vegetation. (so, why would they need to see colour ? but maybe, they need to be aware of various desert insect species? - just wondering. I am all happy that at least gr. squirrels can see full rainbow, but still puzzled - why are tree sqs different?

So, I find it interesting that while tree squirrels are (or believed to be) red-green colour blind, ground squirrels are "full-colour" creatures.

That gives me some glimmer of hope that, perhaps, in this one respect tree squirrels are different from rats and do see full rainbow.

And one more thing to remember: these conclusions are based on the comparison of colour-receptors, and - again, in simple terms - rats and mice do not have enough of colour receptors like people do.
Scientists created various experiments based on this knowledge that seem to confirm the hypothesis that rats and mice are red-green colour blind.
But last couple of decades have been showing that relying on comparative studies between animals and humans may not always produce accurate results. (in other words, perhaps, there are some other mechanisms that regular colour perceptions in animals that are different from humans').
But this is all just speculation and cannot be proved.

Hope this helps

And that's not the only difference in ground squirrel vs. tree squirrel vision. They typically have yellow-tinted eye lenses, the ground squirrel having darker yellow lenses than tree squirrels.

As a fun fact, in contrast to humans where we have a central focus points for our cones, squirrels have it all over their retina so they have excellent peripheral vision.

Astra, since I am doing a study on visual and UV communication in spiders, I am very interested in this subject. It is my understanding, however, that they are able to reasonably hypothesize vision capabilities based on the rods and cones the organism has (and of course with some experimentation and retina mapping). There is a difference in these rods and cones between tree squirrels and ground squirrels, with ground squirrels having many many cones and much more than tree squirrels. The darker yellow lenses in ground squirrels are also capable of creating better contrast in color. All in all, ground squirrels are better adapted to live in bright light environments than tree squirrels. A paper I found on ground squirrels found that they also had dichromatic vision (Jacobs et al. 1984), though it is an older paper (and I found one from 1976 too) and I'm not sure if there is anything a little more recent discussing the subject.

Gerald H. Jacobs seems to have done A LOT of squirrel vision research in the 70s and 80s. If you happen to have any citations or PDFs of recent papers I would love to read them.