Bitterns are breeding at RSPB Leighton Moss in Silverdale for the first time in a decade, following the introduction of new methods of managing the nature reserve four years ago.
As an unusual cousin of the more familiar grey heron, bitterns rely on reedbeds to live in – a now rare habitat in the UK, with Leighton Moss being the largest one in North West England.
Jarrod Sneyd, Site Manager at Leighton Moss said: “Leighton Moss has always been synonymous with bitterns. Whilst we have consistently had them living here throughout the seasons, for the last 10 years they have sadly not been breeding. The reasons why are complex. Leighton Moss is an old reedbed, having formed after the First World War and aging reedbed tends to be quite dry. Bitterns like young, wet reedbeds where they can catch fish, so RSPB staff and volunteers spend a lot of time managing the site in a way that halts its aging process, and creates the conditions that bitterns and lots of other wildlife need to thrive.”
Reedbed is very important to conserve in the UK as a lot of it has been lost through drainage for agriculture and development. In the late 1990s, bitterns were almost wiped out in this country, due to the loss of the reedbed habitat on which they depend. At that time Leighton Moss was one of only a few sites in the country where bitterns were clinging on.
Just eleven booming male bitterns were left, with three of those at Leighton Moss and the majority of the others in East Anglia. Since then, the RSPB and other nature conservation organisations have been working hard to save the species and it has been successful, with 166 males recorded in 2017 – the strongholds being the Avalon Marshes in Somerset and the reedbeds of East Anglia, but sadly this national success was not being mirrored at Leighton Moss.
Jarrod continued: “The traditional methods that have always worked in the past when managing Leighton Moss for bitterns, had recently stopped being so effective, which is why these birds sadly stopped breeding here. Lots of research went into how we might be able to improve the reedbed for bitterns once more. Our expert ecologists and wardens embarked on new, experimental methods of managing the reedbed four years ago, including digging out parts of the reedbed, temporarily drying out some areas and introducing deer management. This has encouraged the reed and other plants to grow in areas where they were struggling. It’s still early days but we’re delighted with the results so far. The reedbed has responded really well to the changes and the fact we have a bittern nest once more is a really encouraging sign.”
Bittern populations are monitored by recording the number of ‘booming’ males. Booming is the unusual song of the male birds, a deep sound similar to blowing over the top of a glass bottle. When fully booming, a male can be heard for several kilometres.