info about the gizzard.

"A bird swallows small bits of gravel that act as 'teeth' in the gizzard, breaking down hard food such as seeds and thus helping digestion." (Solomon et al., 2002).
These stones are called gizzard stones or gastroliths and are usually smooth and round from the polishing action in the animal's stomach. When too smooth to do their required work, they may be passed or regurgitated.

 

Most people don't realize birds have other things besides crops, and start to think all the digesting goes on in the crop. But really the crop is just a storage sack that does little in digestion. Then the gizzard, which grinds it all up, and the proventriculous (I probably killed the spelling) which is the "stomach" of birds. Oystershell is easier to break up, so it's digested I belive, rather than passing through like the rocks. That's why in grit, you should have granite, since 'soft' oystershell doesn't do much for digestion aid.

 

So I see that at our feed store they have available pigeon grit in a 10 lb bag, but is it necessary or could a person just make a shovel full of tiny gravel available to them? In the wild they obviously find their own little rocks. Would they need grit if I turned them out? or would they find their own? How long would they have to be out each day in order to find their own grit?

 

possible, but the grit sold is clean, so would be better IMO, pluse some have added minerals. they need crushed oystershell in a seperate crock for calcium.