hi, i need to have a science fair in 1 week. I would like to do, Are animals Color Blind? and i need to know how I would go about testing that. Cecil had a column on it I belive, but never said how to test it. I need ideas, please post!
Thanks
hi, I need to have a science fair in 7 days, and I would like to do Are Animals Color Blind? Please tell me how I could test this!
Thanks
I remember when they tested me they used numbers hidden in coloured dots to see if I was colour blind.
This could work, but you’d need to teach them to count first.
You might get better responses in GQ; I’ve asked a mod to move this.
Also, you’re going to have to modify this question. Some animals are color-blind, some are not. It might be helpful to let people know what type of animal you’d like to experiment with.
Lastly, don’t wait so long next time. It’s usually easier to do these things in a not-at-the-last-minute type of timeframe.
Well, you could get some pigeons and offer them a choice between several differently colored feed containers. The pigeon is unable to see into the container, so it randomly tries each. You then rearrange position of the containers, however the “reward” (corn kernel) is always in the blue (or red or whatever) container.
After repeating this 100 times and recording the order that the pigeon tries the containers, see if the bird learns to check the blue container first.
You’re going to have to modify this question. Some animals are color-blind, some are not. It might be helpful to let people know what type of animal you’d like to experiment with.
Also, don’t wait so long next time. It’s usually easier to do these things in a not-at-the-last-minute type of timeframe.
vetbridge: Possible, but you’d have to make sure the containers are the same value, so they don’t look different to a colorblind animal.
Most mammals, with the exception of some primates (including us) have poor color vision. Most birds and many other animals have better color vision than us.
Humans, apes, and Old World Monkeys (and some other primates) have three kinds of color receptors (cones) in the retina. This gives the range of color vision that we are familiar with.
Most other mammals have only two kinds of color receptors in the retina. They are equivalent to humans with red-green color blindness. They have only a limited range of color vision compared to humans. Sea mammals, including whales and seals, have only one kind of receptor and see the world in shades of gray.
Birds and many other vertebrates including many reptiles and fish have four kinds of color receptors. They can see ultraviolet wavelengths invisible to use, and a range of colors that is impossible for us to imagine. Many insects, including bees, have color vision and can see into the ultraviolet.
As vetbridge suggests, color vision can be tested by associating food or other reward with color discrimination. However, one must be careful that the containers or other signals offered differ only in color, and not in brightness. For example, a red and a green container might be perceived as light gray and dark gray and thus be distinguishable to the animal even though it lacks color vision. Such factors are difficult to control without access to the proper measuring equipment.
A terse answer to the actual question is that some animals, particularly birds, have better color vision than people do–can distinguish more colors and see into the UV range. There is an excellent article from Scientific American July 2006 on this (need to pay to read full article. Or just go to the library).
Hopefully, the OP means she needs to have a topic in one week. I can say right now that any actual project, and especially one like this, is going to take a lot longer than a week.
I would also like to warn the OP to be sure she knows the rules for her science fair. When I was in school, our science fairs became subject to an increasingly restrictive set of rules, and by the time I graduated, we were not allowed to do any experiment which involved any living organism (among other restrictions). If your school district has similar rules, then you won’t be able to do this experiment.
All that said, the way you’d test this is by training the animal, and seeing what sort of training it responds to. To start with, you’d need two opaque and sealable (scent-proof) containers. Put a treat of some sort that the animal likes in one of them, seal them both, and put them both down in front of the animal (flip a coin each time to decide which one is on the left and which is on the right). Watch the animal and wait. As soon as the animal chooses one container (this might mean the first one the animal touches, for instance), open that container and empty out the contents (if any) for the animal, and take the other one away unopened. Incidentally, you’ll need to keep records of everything that goes on in this stage, so you can be sure that the animal can’t tell which one has the treat by other means. Do this many times, until the animal learns the game, and immediately picks a container as soon as the game starts.
Now, you’ll start labelling the containers. Use the same two containers, but now put a big white label on one container, and a big black label on the other. Make the two labels as alike as you can, aside from the color. Again, you’ll be picking randomly which to put on the left and which on the right, but always put the treat in the white container. If the animal is moderately intelligent, like most mammals, it should relatively quickly figure out that the white container always has the treat, and always pick that one. Like before, do this many times, until the animal always picks the white container. I’m assuming here that the animal can distinguish between black and white.
Now, do the same thing, except label the containers with two different colors, say, red and green, and always put the treat in the red. If the animal can distinguish between red and green, it should quickly learn to always pick the red one (at least as quickly as it learned to always pick the white one). But if the animal can’t distinguish between them, it won’t matter how smart it is, it’ll just pick randomly between them. So if, after many trials (as many as it took to learn the black-and-white game) the animal usually picks the correct container, it can tell the difference between those two colors, but if, after many trials, it doesn’t, then it can’t tell the difference.
Excellent summary of the testing scenario. I would like to add that when the two colors are chosen that they be of the same luminescence. If there is a great discrepency between the color intensities then the animal may only be responding to that (i.e. light green versus dark red may appear as light gray versus dark gray to the color-blond eye). Does anyone know how to account for this in real world color selection?
Welcome to the SDMB, Whatshername.
Posting the same topic in two different forums is called cross-posting and isn’t permitted here. That’s why I’ve moved one of your threads from the Comments on Cecil’s Columns forums to the General Questions forum and merged the two threads into one. Not a huge deal, just keep it in mind for the future.
bibliophage
moderator CCC
I guess if there’s one thing that distinguishes most science fairs as antithetical to the spirit of science is the notion that students are going to “do” a project, as inadvertently signalled by the OP’s post. If only teachers would get across the idea to their students that the point of science is to try to find something out, it would make all the difference in the world. And maybe that’s what the OP is really saying. But I’ve spent a lifetime judging these things, on every level from classroom to state, and I see the same thing over and over. Chronos, as usual, gives a lovely way to investigate the question. But, of course, if the OP goes ahead with that plan, it’s a significant step away from science. It’s good, but it’s following a recipe. Clearly, the best thing we can do with students is to get them to pose a researchable question, and then help them devise a way to answer it. That’s science. I hope this child has learned her lesson, but I fear that she’s already learned it too well from her school. DO a project. Get a tri-fold board. Get your display ready. Prepare your talk. Be sure your written report is punctuated correctly. Don’t chew gum. etc. etc.
(stepping down from soapbox, now)
I’d say almost impossible - it may be the case, for example, that an animal has monochrome vision with only one type of receptor, but that the peak sensitivity of that receptor is in, say, the green part of the visible spectrum; so green objects would naturally appear lighter/brighter than, say, red ones - even though there would be no ability to distinguish red from green.
I did consider the radience issue, but decided not to address it for the sake of simplicity. One possible way to work around it is to have a large number of different containers, of various hues and shades of red and green. For each trial, you would randomly pick one red container and one green container, and then put the treat in the one which is a shade of red. But this would significantly increase the number of trials needed, and make the statistical analysis more complicated, both of which would take more time, which I suspect the OP doesn’t have. As it is, I’m already doubtful that the project could be completed in the few months before the end of the semester.
Hmm, would a human friend with color blindness be able to act as QA to see if they appear different (other than the color)?
One possibly quite easy experiment would be to find a picture of a flower, print out a number of different-coloured versions of it (rotating the hue a bit in Photoshop or any other image editor); print these all out, print one that is totally desaturated also. Affix the pictures of flowers to bamboo skewers and stick them in the soil in a garden frequented by bees; keep a tally of the number of times any bee shows any interest in each of them.
Don’t forget to rotate the hue through the ultraviolet part of the spectrum, too. Anyone know where to get some ultraviolet ink? 
Note how different these flowers flowers appear in normal (left) and UV light (right). The one on the right is something like a bee’s-eye view (and bird’s, too), although we really can’t imagine what it really looks like.
I think the experiment could still yield results even if the flowers were not rendered in lifelike form - even without the UV - I’ve seen bees investigating pictures of flowers printed on clothing.
Also, if the OP happens to live somewhere where hummingbirds visit, a similar experiment could be performed with little tubes of sugar water stuck into different-coloured paper flowers.
But “color-blind” people don’t see the world as totally grayscale. Or at least I’ve never heard of it. As far as I know, they’re deficient in part of the spectrum, but can see other colors normally.