Buffalo wings?

The suspicious hoof tracks Fergus was trying to follow just sort of stop here, at the end of the tunnel. He's not seeing any sign of the bovine he'd glimpsed up ahead, either. There's nowhere for them to have gone, except up through the ceiling. Can the bovines fly? He'd never considered it, but that would explain a lot.

(Not sure why the ceiling tunnel is so bright. Guess I just wasn't sure how to make it obvious that he was looking at an opening up there.)