All recordings April, Norfolk, England unless noted .
Little Grebe singing duet.
Great Crested Grebe pair in altercation with a coot which was investigating their nest (May, Essex).
Water Rails have a wide variety of grunting and squealing calls. All recordings shortly before dawn in April at Lakenheath Fen, Suffolk (presumed, birds not seen).
reduced time scale
Contact call often heard in winter (Feb, Herts).
Distant Bittern booming (the low frequency sound is better heard with headphones).