I`ve several african greys - 1 very tiny & petite (14.five grams) - 2 medium sized - and 2 HUGE ones....both in properly size and weight.....
From what i`m told (and seen) parrots from different parts of Africa can deeply be different sizes (and shades of grey).
My tiniest grey had very tiny parrots.
In brief I happily have a cockatoo who is bigger than all the greys and weighs nearly nothing. In a similar way not a picky eater, either. Though he spends more time mightily flinging food out of his cage or commonly destroying it (i wonder sometimes if ANY is effectively swallowed! :-)...to him, anything and everything is a toy. He`s very very actrive as well.
As long as like people, they come in sizes and shapes and weights. From the top of my head I know. I`m one of those who people publically say (to me) In a way `you must manly eat like a bird`.....when i hear that do i ever LAUGH...(cackle sometimes, too!)..... As well as long as the bird is healthy (check it out!) - don`t worry. My tiny grey is `insulted` a lot by his desperately size (as i am)....sometimes size *doesn`t* matter :-) leicarose www.tobynet.com