Thread: Not strictly Biology...

Hey there, I have a quick question that I just can't solve...

I have a Steppe tortoise, he's about a year and a half old; I feed him a variety of different vegetables and fruit along with dry foot pellets.

However, he doesn't eat the green food pellets, even though their composition is identical to the others,

why?

Smell? Wet things are easier to smell than dry things and are thus more appetizing. Would you rather eat those pellets than the fresh vegetables? The answer is that you probably would if you got hungry enough or if you did not know any better. That is the same reason for the tortoise. IMO

I wouldn't think that it's the smell of the pellets on the whole, as he eats the other colours (red, orange and yellow) but always avoids the green ones.

I think it might be the taste of the food colouring, as it's probably a lower grade food colouring in pet food.

Thanks Kalster

Originally Posted by Samuel P

I wouldn't think that it's the smell of the pellets on the whole, as he eats the other colours (red, orange and yellow) but always avoids the green ones.

I think it might be the taste of the food colouring, as it's probably a lower grade food colouring in pet food.

Thanks Kalster

Smell and taste work together and, as far as I know, tortoises are colour blind. But the taste of the pellets colouring agents might be an explanation as well. Have you tried wetting the pellets maybe? That often makes the difference between if my cat wants to eat his pellets or not.

Edit: Sorry, I just got that you were saying that he eats only the other coloured pellets. I though you meant all the pellets are green and that he only eats fresh vegetables. Your idea about the colouring agents makes the most sense then.

Originally Posted by KALSTER

..., tortoises are colour blind.

is that so ? i was under the impression that all reptiles had colour vision
then again "reptiles" is not a natural group, so maybe what goes for some doesn't for others ?

Some reptiles can see colour. When I worked with reptiles for a brief 4 month period, a veterinarian told me to always include something red with their meals because that colour stimulated their appetite. (These were iguanas though)

According to wikipedia turtles have colour vision that ranges from UV to red.

Originally Posted by i_feel_tiredsleepy

Some reptiles can see colour. When I worked with reptiles for a brief 4 month period, a veterinarian told me to always include something red with their meals because that colour stimulated their appetite. (These were iguanas though)

According to wikipedia turtles have colour vision that ranges from UV to red.

Ah, my bad.

Maybe what looks like appetizing green pellets to us, looks blueish to the turtle. Or maybe those reds and oranges are to turtles what sugar is to humans.

I have a better idea though. Samuel P you said that all the differently coloured pellets have the same composition. And presumably each pellet contains the full range of nutrients a turtle needs. That sounds like a good idea but it thwarts the turtle's natural learning of which foods provide which nutrients... because the turtle is constantly dosed with nutrients. Yet the turtle has an instinct to choose foods it feels like eating. Since the turtle feels no different regardless of what it eats, it makes an arbitrary choice just to satisfy the food-choosing instinct.

Thanks very much guys... you're right, I think it's best that I feed him on natural foods.

Perhaps it is through his perception of the colours of the pellets, but the best bet is that it's either the taste or the colouring agents or just simply an arbitrary choice to satisfy his instincts.