Numbers of nesting bitterns are at their highest since records began in 1990, with 51 male bitterns recorded across 33 sites in England, according to a survey conducted by the RSPB. Moreover, bitterns have been found nesting in the East Anglian fens for the first time since before the Second World War.

Having been extinct in Britain from 1886 to 1911, bittern numbers reached an all-time low in 1997 with just 11 males recorded. By 2004 this had recovered to 55 males, which stands as the record for recent times. This figure dropped back to 44 last year. Bitterns remain difficult to monitor, however, as they live in reedbeds and can be extremely difficult to spot.

East Anglia was the bittern’s original habitat, and the reedbeds where they have been discovered were developed specially by a private landowner from Grade 1 arable land. The 150-acre site in Cambridgeshire was converted to wetland with the help of the RSPB.

Dr Tom Tew, Natural England’s Chief Scientist, says ‘Natural England and its partners are committed to creating new wetlands and the bittern’s success at newly created reedbeds is an example of how effective we can be.’