Setback in bitterns’ recovery

The bittern, one of Britain’s rarest birds, has suffered a setback in its recovery, researchers have revealed.

A new UK-wide survey of the birds, which are related to the more familiar grey heron, found that there was a minimum of 46 male bitterns this year.

Researchers say that, although this is an improvement from a 1997 survey, which found only 11 males in Britain, it is still a “significant drop” from last year’s count of 55.

The bittern is dependent upon large tracts of wet reedbed in order to find food, such as fish and amphibians. However, the drainage of wetlands and the general deterioration of reedbeds, which began in the 1950s has led to the decline of the species, which continued until the late 1990s.

The latest research, organised by English Nature and the RSPB, monitored the birds’ distinctive booming call, (males can be heard for up to three miles), allowing researchers to count these usually secretive birds.

Researchers found that Suffolk is now the UK’s most important county for bitterns, with a minimum of 20 booming males. The species’ survival also improved in some other counties. Dorset recorded its first booming bittern in recent years, while Cambridgeshire’s population doubled from two to four.

However, researchers found that Norfolk’s bittern population suffered a “significant decline”, falling from 19 males last year to 11 this year, with the most noticeable drop occurring in the Broads.

There were also no bitterns found in Wales, Kent and Somerset this year – last year one bird each was found in Wales and Somerset, while three were discovered in Kent.

Commenting on the results of the research, Allan Drewitt, senior ornithologist for English Nature said: “The record of 55 booming males in 2004 was a major achievement and fantastic news for all those working hard to establish a thriving population of bitterns in the UK. Although still a significant improvement on past figures, the drop in numbers this year is a reminder that we must continue to create new reedbeds if we are to secure a long-term future for this rare and vulnerable bird.”

Dr Ken Smith of the RSPB said: “In spite of this small setback the recovery of the breeding bittern population is a conservation success story and a credit to the wide range of organisations involved. The European Union’s LIFE fund, which has financed a good deal of the work, deserves particular praise. However, the bittern population still has some way to go before it is secure.”

(KMcA/SP)