I was disappointed to find ventriculus [vin-TRICK-ya-lus] didn't mean a bird that could throw its voice. Instead it's just a fancy word for gizzard. Ventriculus, gizzard, whatever you want to call it, it's actually part of a bird's digestive system--kind of a second stomach--where it grinds up those pesky hard to digest things like clam shells. How? It rotates whatever is in there against whatever else is in there, kind of like polishing stones in a tumbler. To help the process, birds that can't leave the hard nuts or shellfish alone will sometimes snack on sand or gravel between meals. :)
And just for the record, meadowlarks and terns can throw their voices. :)
