Bitterns are counted by researchers by listening to the male’s foghorn-like song. And over 150 males have been recorded in England and Wales this year.

It is expected that numbers did not surpass since early in the 19th century. There were 140 booming males across 61 sites that were recorded during last year. They have been recorded both at Lakenheath Fen, and Roswell Pits, in Ely, at Wicken Fen.

Bittern numbers reached a peak when there were around 80 booming males in the 1950s, however the number decreased to only 11 males in England in 1997.

As a result of concern over a second UK extinction, a concerted conservation program was launched, which is helping in the current recovery. Between the 1870s and 1911, the bittern was not there as a breeding bird.

When it comes to breeding season, the bittern has a preference for sizeable tracts of wet reedbed, which is a habitat that in the UK became scarce and under managed two decades ago.

According to Simon Wotton, a RSPB conservation scientist, the bittern was heading in the direction of a second extinction in the UK in the late 1990s. Wotton added that this was mainly because its preferred habitat was drying out and needed careful management, restoration in addition to habitat recreation.

Wotton added, “But thanks to efforts to improve the habitat, combined with significant funding from two projects under the European Union Life Program, the bittern was saved, and we’re delighted that its success keeps going from strength to strength”.