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Single mums settle at Somerset reserve

Last modified: 23 June 2008

Adult bittern wading in reedbed at the Lee Valley Country Park

At last, the bittern is discovering sites specifically created for it away from its East Anglian stronghold

Image: Andy Hay

A project to encourage the bittern - one of Britain's rarest birds - to spread from its East Anglian stronghold has met with success as two bittern nests have been found by staff at Ham Wall RSPB nature reserve in Somerset. The first time the birds have nested in the county for 40 years.

In 1997, the UK bittern population was down to just 11 males, principally concentrated in East Anglia, fuelling fears that the bittern may be heading for UK extinction.

An intensive rescue package, largely funded by the European Union, improved the quality of the bird’s reedbed habitat at core sites and the population increased dramatically, reaching a recent high of 55 males in 2004.

However, too many of these birds are still concentrated in freshwater wetlands along East Anglia's low-lying coast, ultimately putting the bulk of the UK population at risk from rising sea levels triggered, in part, by climate change. 

Great news

Simon Wotton is an RSPB research biologist and national organiser of the Bittern Monitoring Programme. He said: 'It is great news that at last bitterns are beginning to recolonise parts of their former range, especially when it’s at a site that’s been created with them in mind. The bitterns' core populations are concentrated in areas threatened by sea level rise. The Somerset birds hopefully represent the start of a new population, not subject to this environmental threat.'

Male bitterns are known for their habit of mating with a number of females then abandoning their mates to raise the young by themselves – known as polygyny. The Somerset bird has managed to breed with two females, doubling the chances of success.

We've been keeping our fingers crossed that the birds would breed

Steve Hughes is the RSPB’s site manager for Ham Wall nature reserve. He said: 'We've been listening to the distinctive booming song of this male bittern for the past couple of months and keeping our fingers crossed that the birds would breed.

'This is the first time that these birds have nested here and the birds' adoption of the site is a fantastic tribute to the hard work of volunteers and RSPB staff who have created the perfect habitat for bitterns at Ham Wall and the neighboring National Nature Reserve at Shapwick Heath.'

The RSPB first purchased land at Ham Wall in 1994. The reserve, developed on former peat workings, is one of a network of reedbed sites, across Britain, which have been created specifically for the bittern using European Union funding. This is the first time that bitterns have nested on one of these newly-created European-funded sites. The RSPB's work at the site has been supported by many organisations, including the EU Life Fund, Heritage Lottery Fund, Leader+ and SITA trust through the Government's Landfill Communities Fund.

The bittern, a distant relative of the more familiar grey heron, was extinct in Britain between 1886 and 1911, when the birds returned to Hickling Broad in Norfolk. The secretive bittern nests in reedbeds where it is most often located in spring by the males’ distinctive booming song. The bittern’s boom can be heard for up to three kilometers.

Last year, surveyors from the RSPB and Natural England Bittern Monitoring Programme recorded a minimum of 51 male bitterns across 33 sites. However, more detailed investigation revealed that the birds had only successfully nested at 12 sites, involving 27 nests. The Bittern Monitoring Programme is part of the Action for Birds in England program, a conservation partnership between Natural England and the RSPB.

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