G.T. Hamilton wrote:

Terrence M Marks wrote:

Can pigs see colours, or, like dogs, are they colour-blind?

Terrence Marks
Remember-Jesus is your friend.
normal@grove.ufl.edu

 Not all animals see in black and white, like it is commonly mistaken.
Dogs and cats and the like can see colour, just not all of them. They
can only see the lower end of the spectrum and distinguish from that,
blue green violet etc. Pigs I'm not too sure, but I'd be willing to bet
on the same for them.

Based on my minimal knowledge of biology, it would depend on whether the
animal in question is nocturnal or a carnivore vs herbivore.

The Rods are the light/dark sensors and are much more sensitive in low
light, so night creatures will have more and so minimal if any colour
vision.  Predators like big cats also have a lot of rods, as it makes
camoflage less effective (I seem to remember that is the reasoning
anyway)

Herbivores and omnivores tend to need good colour vision to be able to
identify their food.  It would be important to be able to distinguish
between green and ripe fruit _before_ you eat it.

Well, that's my 10 cents.

-- 
Barry Cadwgan ( BCADWGAN@FL.NET.AU )
"The end does not justify the means.  
 The end is the sum of the means,
 as the road travelled determines the destination." 
Valijon Starbringer (Hellflower Trilogy, Eluki bes Shahar)