Numbers Still Dangerously Low
RSPB Press Release, 21st April 1999

Numbers of Britain's most secretive bird, the bittern, remain at a dangerously low level with only 13 or 14 males booming this spring, reports the RSPB. Hopes of an increase this spring are receding and the Society is calling for any reports of bitterns heard or seen to be sent in.

Preliminary counts this spring of the distinctive calling males reveal that the stronghold in East Anglia has only eight or nine birds - three at Minsmere, Suffolk, one at Titchwell, Norfolk (all on RSPB reserves), three in The Broads , and one or two at other sites. Three birds are in Lancashire at the RSPB's Leighton Moss reserve and a further two in two other English counties.

Bittern numbers are estimated by counting the males when they display in spring, giving their loud booming call. Individual calls can be identified by their 'voice-print', giving an accurate count. Some other birds can also be located using radio-transmitters fitted when they were young but the whereabouts of only four or five of last year's tagged birds is known - the remaining 14 have vanished.

The booming call is given from the depths of a reedbed and can be heard more than a mile away. Anyone hearing a bittern, or seeing one with a radio tag or ring on its leg, should report it to Gillian Gilbert, RSPB, The Lodge, Sandy, Bedfordshire SG19 2DL. Telephone on 01767 680551 or e-mail on gillian.gilbert@rspb.org.uk.

Gillian Gilbert, RSPB research biologist, said: "Bitterns are critically endangered in the UK. Numbers of calling males have halved in the last few years and the signs so far this year do not indicate any increase. We are desperate to know about any bitterns heard away from the East Anglian or Lancashire strongholds and of any sightings of tagged birds."

For further information contact:

• Photographs of bittern are available in traditional or digital format from RSPB Images - ring 0171 608 7325 and ask for Zoe Beech.
• Video film of bitterns is available from the RSPB press office - ring 01767 681577.

Additional notes:

1. The bittern is one of the rarest of the UK's threatened breeding birds. It has been in decline since the mid-l950s. In 1954 there were 78-83 booming males in seven counties. By 1987 this had declined to 22-25, and by 1994 there were only 15 or 16. Numbers began to recover with 22 males in 1996 but fell dramatically to only 11 in 1997 and 13 in 1998.
2. Bitterns are secretive members of the heron family which are dependent on reedbeds where they breed and feed mainly on fish and amphibians. They can suffer in severe winters when many die if their wetland habitats become frozen.
3. The UK breeding population of bitterns is now concentrated in Norfolk, Suffolk and Lancashire and the main threat to them is habitat deterioration. In winter they can be found further afield on gravel pits, rivers and lakes. Some bitterns from continental Europe come to the UK for the winter to escape the freezing conditions elsewhere.
4. The bittern has been included in the UK Government's Biodiversity Action Plans with the RSPB as lead partner. A grant of £1.5 million has been given by the EU's LIFE programme to a partnership of conservation organisations and is being used to restore and extend reedbeds across the UK.