Late winter and early spring is the key time for us to start listening out for bitterns here at Leighton Moss. The males begin to boom in order to attract a mate and on calm days the sound of the first birds ‘tuning-up’ are a cause of celebration for staff, volunteers and visitors alike.
Bitterns have had something of a bumpy ride over the decades and at one point Leighton Moss held around a quarter of the entire UK population. Bearing in mind that the population at that time barely numbered into double figures, things were looking pretty critical for this enigmatic reed-dweller.
Thankfully, through the concerted efforts of the RSPB and other conservation organisations, the fortunes of this secretive heron have taken a turn for the better in recent years and current estimates put the number of booming males in Britain at around 200 birds!
This huge success is all down to the creation of new wetlands and the improvement of existing reedbed habitats. Our better understanding of the bitterns’ needs has allowed us to take drastic action and it has really paid off.
Here at Leighton Moss, we implemented some dynamic water level management and experimental cutting that allowed for a greater diversity of mosaic habitats within the vast reedbeds. This not only improved the health of the overall site but also made the reserve a better place for European eels to live. This rapidly declining fish is a major part of the diet of bitterns (amongst other birds and otters too) and by creating improved areas for eels we ensure good numbers can thrive here and consequently be a significant food source for several key species.
Last year you may recall that we were thrilled to discover three booming male bitterns at Leighton Moss – the first time so many had been heard here since the 1990s. Already this spring we have identified an amazing six males booming on the reserve. This is clear evidence that the work that our wardens and volunteers, with advice from the RSPB ecology team, set out to do has worked as they’d hoped it would. It is possible that one or two the boomers currently in song on the reserve may move on but it certainly shows that the extensive reedbeds of Leighton Moss are once again providing an ideal home for this most unusual of birds. And with the new cell-bed project well under way we can only expect to see and hear yet more bitterns here in the years to come.
Booming is best listened for at dawn and dusk but in the past week or so our males have been continuing to boom throughout the day. The best place to listen for them is along the Causeway. Due to limited safe parking on the road at the top of the Causeway, we advise local visitors to use our car park and then walk through the reserve via the boardwalk to avoid having to walk along the road.
At the time of writing we are still in lockdown and so until restrictions ease, we ask that you follow the legislation around non-essential travel and please visit your most local nature reserves and green spaces only.
Please keep checking this blog along with our Facebook page and Twitter account for details regarding re-opening.
Bittern photo by Mike Malpass