This year the annual butterbump survey has recorded another increase with 198 booming male bitterns found at 89 sites across England and Wales, of which 102 were found on RSPB reserves.
From historical sources, it is clear that Bitterns once bred across the UK. By the 1880s, however, they were considered extinct as a breeding species in the UK. Following recolonisation early in the 20th Century, initially in the Norfolk Broads, numbers increased to a peak of about 80 booming males in the 1950s, with most in the Broads. There then followed a steady decline, leading to a programme of monitoring and research to determine accurately the number of individuals at the few sites that still retained Bitterns in the 1980s and to help diagnose the causes of decline and to identify a means of halting and then reversing it.