Land management for bitterns
7 October 2008
The bittern is a shy species, favouring wetlands dominated by common reed (Phragmites australis).
Bitterns feed on fish and amphibians, which they get from within the reedbed or within the reeds’ edge. They rarely venture out into the open. The bittern is one of our rarest breeding birds, currently occupying only about 30 sites in England, with overwintering birds at 50 or more sites.
The UK breeding population fell by over 70% between the 1950s and 1990s, largely due to loss of reedbed habitat and the lack of management, as well as the drying out of existing reedbeds.
Considerable effort by the RSPB and Natural England, in partnership with others, has begun to reverse the changes. Numbers have increased from a low point of 11 booming males in 1997 to 76 in 2008.
What do bitterns need?
Throughout the summer, bitterns need large, undisturbed wet reedbeds, with good fish populations. Extensive (at least 20 hectares) undisturbed wet reedbeds or wetland complexes to provide cover from February to August, with good fish populations (preferably of rudd, eels and sticklebacks) for feeding.
'Throughout the summer, bitterns need large, undisturbed wet reedbeds, with good fish populations'
Bitterns nest from April to June, but males may establish their territories as early as February. The males’ territories and females’ nests are found in reedbeds or tall fen vegetation, usually with standing water in and around it.
Adults feed within the reedbed and chicks are fed predominantly on any fish that venture into this area of wetland vegetation. In winter, wet reedbed or tall vegetation, with good fish populations, is required.
Any size of wet reedbed or tall vegetation, with good fish populations for feeding, offers bitterns cover through the winter. Many bitterns come to the UK from colder northern European countries from October to March.
Our own breeding birds and the additional continental visitors may occur at a greater range of smaller wetland sites with reedbeds or reed fringes in the winter months. These sites need good fish populations and some tall vegetation with standing water in which the birds can feed. Flowing water is advantageous in maintaining open conditions in severe weather.