Scientists are a little less certain about whether birds can release gassy buildup from the mouth, though. There's no official documentation of a bird burp (it's not a common field of research), but most ornithologists suspect that if a bird needed to burp, it would have no trouble doing so."Birds are able to excrete lots of things through their mouth," says Todd Katzner, the director of conservation and field research at the National Aviary in Pittsburgh."The fact that birds can regurgitate food for their young suggests that they can also reverse the direction of other things down there. I'd be pretty surprised if birds didn't burp."