Bitterns are marsh / wetland birds with a range that covers Europe, Africa, Australia, Asia and the Americas. I flight, they are identified by the fact that they fly with their necks retracted, not outstretched.
Below are images of the different Bittern species. Each photo is linked the respective species page with information and additional photos.
If you can’t find the bird that you want to ID on this page, please try the Heron, Egret or Ibis Species Photo Galleries, as these groups of birds share many physical similarities and can, therefore, easily be confused.