Debunk this: When you shine a light at a carnivore, eyes are red while herbivore eyes are green?

Question

I have heard that you can tell the diet of a creature by the color that its eyes glow when a light is shined at them (specifically when they are in the dark).

Carnivore - eyes glow red

Herbivore - eyes glow green

Omnivore - eyes glow yellow

Is this true or is it an old wives tale?

I can't find any information to prove this theory one way or another...help!

Answer 1

Hmmm. So what does it mean that my eyes always glow red in flash-photography?

This is because of light reflecting off the retina at the back of the eye.

Some animals, nocturnal ones, have a special layer at the back of the retina called the "tapetum lucidum" ("shining carpet"), which is adapted to actually reflect more light, giving them an advantage in low-light conditions,because it gives the photoreceptors in their retina twice as much chance to pick-up any photons entering the eye. It doesn't matter whether they are carnivores or herbivores.

http://en.wikipedia.org/wiki/Tapetum_luc...

Diurnal (daytime) animals instead have a layer called the choroid, which is black, and absorbs light. This makes their vision sharper in bright-light conditions, but means they don't see as well at night-time. So any light reflecting off their retina will be predominantly red, as it has reflected off blood vessels.

http://en.wikipedia.org/wiki/Choroid

Answer 2

it would be easy to do.  Simply shine light in various animals eyes.

The amount of rabbits and other rodents with red eyes should make you realise how ridiculous the claim is.

Answer 3

I have anecdotal evidence. I took a flash photo of our old family pet dog- one eye was green, the other yellow.

the rest of the time his eyes were red.

I have also taken a picture of my daughters' pet rabbit and it weas red eye all the way. Maybe it's a vampire rabbit :-)