BITTERNS have found their voice this week at RSPB Minsmere nature reserve, near Westleton, signalling the arrival of spring. The first bittern was heard grunting - a precursor to their famous deep boom - on Friday, February 27.

BITTERNS have found their voice this week at RSPB Minsmere nature reserve, near Westleton, signalling the arrival of spring.

The first bittern was heard grunting - a precursor to their famous deep boom - on Friday, February 27. By Tuesday there were at least three male bitterns grunting.

RSPB spokesman Ian Barthorpe said: 'As their throat muscles strengthen, these early grunts will soon turn to a full-throated boom, which can be heard from up to one mile away. Many visitors have been lucky enough recently to see bitterns feeding at the edge of reedbed pools or flying low above the reeds. Early mornings are best, but bitterns can be heard throughout the day.

'The bitterns have been quite late starting to boom this year. This may be due to high water levels following recent flooding, but may also reflect the colder winter. They should now boom until late May.'

Minsmere remains the UK stronghold for the bittern. There were just 75 booming males in the UK last spring - a significant increase on previous years - with 11 of those at Minsmere. That compares to just 11 males in the UK in 1997.

Other early spring highlights at Minsmere include avocets, which have returned in good numbers already, Mediterranean gulls and drumming great spotted woodpeckers. The first summer visitors will arrive in the next few weeks, led by species such as chiffchaffs, wheatears and sand martins.

Visitors to Minsmere can join a guided walk to learn more about the special wildlife found there, then enjoy a warming drink or meal in the tearoom, and browse the RSPB shop.