Question:  Do llamas see color?

I am an intern at a Zoo.  I am doing a research project on llama behavior.  I am looking to see if the llamas at the zoo respond differently to zoo visitors wearing staff shirts compared to visitors in normal clothing.  To really study this however, I need to have some background information on llama eyesight.  I was wondering if you have any info, or know where I can obtain info about llama eyesight and/or color perception.  I have been searching everywhere but cannot find anything.  Please let me know if you can help!  I really appreciate it!

Answer:

There are some good references you can check out listed below.  I don't know of any research of vision in camelids, but I would assume that they have dichromatic color vision like other domestic species, meaning they would see mostly blues and yellows.  You might also do a literature search on vision in horses and cattle and extrapolate from that.   Basically, compared to a human, the retina is poorly developed and by behavioral testing,  the visual acuity is estimated at 1.8 cycles per degree in a cow and 18-23 cycles per degree in a horse compared to 36 cpd in a human.  The higher the cpd, the better the visual acuity.  Your research may help us...