The population of male bitterns in the UK fell to just 11 in 1997. Now there's about 230 breeding pairs. It still has a very limited range in the UK, so it's a bird I am always pleased to see.
I have found photographing it quite tricky as it is so well camoflaged. And when it flies it is often only for a few seconds as it moves around the dense reedbeds.
I have had the pleasure....terror...of being in the middle of a fog-filled fen when two bitterns started booming. Even when you know they are there it's pretty freaky.