Bittern numbers increase

Bittern numbers are on the increase,  according to the latest research.

This threatened heron has enjoyed its most successful year since it recolonised the UK in 1911, following 25 years of British extinction.

Conservationists add that this year’s success is even more remarkable, following the long spell of cold weather earlier in the year, which was known to have adversely affected bitterns at many sites.

A UK monitoring programme for this shy bird of reedbeds, has revealed the presence of 87 males, delighting those who have worked so hard to prevent the bittern from becoming extinct in Britain a second time.

The programme recorded 82 males last year, the previous record holder.

Bittern almost extinct in Britain

In 1997 the bittern reached its lowest numbers since the 1920s, when the survey revealed only 11 males.

By the end of the 1980s it was realised that bitterns were in trouble, so a programme of monitoring and research was established, leading to the improved management and restoration of reedbeds.

Additionally, newly-created nature reserves such as the RSPB’s Ham Wall, in Somerset, and Lakenheath Fen, in the Suffolk Fens, now hold one third of all nesting British bitterns.

Dr Mark Avery, the RSPB’s Conservation Director, said: “The bittern is perhaps the best example we have of the value of targeted conservation action. With funding from government, the European Commission and the business sector the bittern has gone from strength to strength. ”

Habitat flood risk

Bitterns nesting in freshwater reedbeds adjacent to the coast in East Anglia are vulnerable to the effects of sea-level rise.

The rise in the bittern population in the Somerset Levels and the East Anglian Fens is welcome news as sites here provide more long-term security for the species in Britain.

Bitterns establish their territories by making a loud ‘booming’ sound, which can be heard for several miles.

By accurately plotting and triangulating these booming males, researchers are able to pinpoint each male, even within extensive reedbeds.

Researchers from the RSPB and Natural England – through the Action for Birds in England programme – recorded bitterns in reedbeds in several English regions, but the stronghold remains East Anglia, which held 62 males (down one from last year), principally along the Suffolk coast, the Norfolk Broads and increasingly in the Fens.

Bittern numbers increasing

Encouragingly, this red list bird is showing signs of increasing its range as booming males were recorded at 47 sites; 43 in 2009.

Last year, there were three booming bitterns in the Somerset Levels, but this year 14 males were recorded. Hopefully, the bird’s four-fold increase will consolidate the bittern’s return to this network of wetlands.

The counties recording the most bitterns in 2010 were:

• Suffolk, with 32 males
• Norfolk, with 22 males
• Somerset, with 14 males
• and Cambridgeshire, with eight males
• Kent and Lincolnshire recorded three males each
• and East Yorkshire recorded two.

The Bittern monitoring programme is funded through Action for Birds in England, a conservation partnership between Natural England and the RSPB