So what would be the ruling in that case, is it a wild pitch and the runner at second could advance, or is the play dead when it hit the bird?
Infield Fry Rule!
When Johnson did it, it was ruled “no pitch” and a dead ball immediately.
http://www.life123.com/question/Randy-Johnson-Hits-a-Bird
If a batted ball hits a bird it’s a dead ball. If said ball lands in fair territory it’s also a ground rule double. This happened in a 1987 game between the Braves & the Mets. Braves outfielder Dion James hit a bird that was flying over left-center field at Shea Stadium. If the ball lands in foul territory it’s a foul ball. If a pitched ball hits a bird it’s a dead ball and considered no pitch.