Hi. I was walking in Hertfordshire today when I heard what sounded like a cross between a pig grunting and a duck. Assuming it was an animal on the ground I walked over towards the tree, and saw a huge black/dark bird fly out of it, making the funny duck noise. It definitely wasn’t a red kite ( had the wrong tail for a kite) but was about that size. I couldn’t see its head. On the way back I could hear it but couldn’t see it. I saw on another thread, someone saw the sane thing in wales last summer. I just wondered if anyone has had any luck identifying it please?