Last Updated: Tuesday 28 August 2018
Bitterns experiencing baby boom
The bittern - a bulky type of heron extinct in the UK at the turn of the 20th Century - has experienced another successful year for breeding, according to an annual national survey carried out by RSPB staff and volunteers.
Scientists count bitterns by listening for the male's foghorn-like booming call, and this year numbers increased to at least 161, recorded at 76 sites. That compares to 157 at 72 sites in 2015, and is a positive sign that bitterns are back from the brink and thriving.
A highlight this year was the discovery of two nests at Otmoor, Oxfordshire - the first time they have been confirmed nesting at this site. Meanwhile in Wales, the first nest for over 30 years was found at Malltraeth Marsh. The first 'booming' was also recorded this year at Newport Wetlands.
Simon Wotton, senior conservation scientist at the RSPB, 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, the bittern was saved and we're delighted to see it going from strength to strength."
Secretive and highly camouflaged birds, bitterns live in wet reedbeds - a habitat which, in the UK had become scarce and under managed by the late 1980s. The increasing number of bitterns identified, thanks to the careful management of reedbeds across the country, shows that conservation really can make a notable difference in bringing species back from the brink. Plus, an increase in reedbeds is also benefiting other species such as reed leopard moths, bearded tits, water voles and even otters.
The bittern was absent as a breeding bird between the 1870s and 1911, and as such was declared extinct in the UK. As well as losing their habitats after England's wetlands were drained, bitterns were also sought after by taxidermists and egg collectors. There are thought to be more stuffed bitterns in Norfolk than there are live birds.
Bittern numbers rose to 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.
Martin Harper, RSPB's conservation director, 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.
"The success of projects like this are even more important as government considers its plan to restore biodiversity in 25 years: a target-led approach to conservation supported by a partnership between government, NGOs and landowners with resources necessary to transform landscapes."
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 2016, 19 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 8 recorded in 2016.
Tips for spotting bitterns
Bitterns can be seen regularly at a number of RSPB sites including the Avalon Marshes, Minsmere, Lakenheath Fen and Ouse Fen. The best time to see bitterns is at dusk or dawn, on clear days. Bitterns boom during the breeding season in spring and early summer (their deep booming call, made by the male to attract a mate, can be heard up to two kilometers away). However winter months are a good time to spot bitterns, as birds from the continent arrive to boost the resident UK population. Prolonged cold weather also makes feeding more difficult, so there is more chance of seeing them in flight as they search for suitable feeding spots.