The bittern – a type of heron extinct in the UK at the turn of the 20th Century – is bouncing back to full recovery. Scientists count bitterns by listening for the male’s foghorn-like booming song, and this year over 150 males have been recorded in England and Wales, making it an exceptional year in recent times, with numbers not thought to be surpassed since early in the 19th Century.
Bittern numbers peaked at around 80 booming males in the 1950s, but had declined to only 11 booming males in England in 1997. Concern over a second UK extinction led to a concerted conservation program which is driving the current recovery. The bittern was absent as a breeding bird between the 1870s and 1911.
During the breeding season, the bittern prefers sizeable tracts of wet reedbed – a habitat which, two decades ago, in the UK had become scarce and under managed.
Simon Wotton is an RSPB conservation scientist. Commenting on the bittern recovery, he said: “In the late 1990s, the bittern was heading towards a second extinction in the UK, largely because its preferred habitat – wet reedbed – was drying out and required intensive management ,restoration and habitat recreation. 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.”
Martin Harper is the RSPB’s conservation director. He added: “The bittern is a species which proves that conservation can be successful, especially when you can identify the reason behind its decline and bring in measures and funding to aid its recovery.”
Over the last 25 years there have been several significant habitat-restoration projects, some of which are now RSPB nature reserves, including:
Ham Wall, in Somerset, which was created from old peat workings from 1995. The bittern has been booming regularly from 2008 with first nesting in that year. In 2015, 17 boomers have been recorded at the site.
Lakenheath, in Suffolk. This wetland site was converted from carrot fields from 1995. Bitterns were first recorded booming here in 2006 and the first confirmed nesting was recorded in 2009. This year six booming males are being recorded on site.
Ouse Fen, in Cambridgeshire. This partnership project with Hanson has seen wetland creation from former mineral workings, which started around 10 years ago. In time, it will be the largest reedbed in the UK. The first confirmed booming was in 2012, with 10 recorded in 2015.
According to this year’s figures, the top UK county for bitterns is Somerset, with over 40 booming males. Following the restoration and extensive creation of large wetlands in the Avalon Marshes, at Ham Wall (RSPB), Shapwick Heath (Natural England) and Westhay Moor (Somerset Wildlife Trust), bitterns became re-established in Somerset in 2008.
East Anglia with over 80 booming male bitterns remains the bittern’s regional stronghold in the UK, particularly in traditional sites on the Suffolk Coast, and in the Norfolk Broads but also increasingly in the Fens, particularly at newly-created habitat.
Over half (over 59 per cent) of the booming males are on sites protected under international law, namely the European Union’s Birds and Habitat’s Directives. These sites, referred to as Special Protection Areas or Special Areas of Conservation, are collectively known as Natura 2000 sites.
Martin Harper added: “These sites have been vital to the conservation of the bittern and other key species in the UK. However, the European Union is consulting on the future of the Birds and Habitats Directives. And we fear this may lead to a weakening of the directives, with potentially disastrous consequences for many threatened species.”
The RSPB is working in partnership with a range of organisations across Europe and across the UK which are encouraging people to take part in a European Commission-led consultation on the Birds and Habitats Directives.