A Bittern has been heard making a mating call in Hertfordshire for the first time in recent history following a long-term conservation project to create more reedbed habitat for the protected species.

Prompted by the near-extinction of the Bittern – a member of the heron family - and led by the RSPB, a huge nationwide conservation effort to create more reedbed habitat took place in the early years of the millennium.

Locally, Herts and Middlesex Wildlife Trust worked with conservation partners and from 2004-2010, doubled the area of Bittern-suitable reedbed in the region to 24 hectares – the equivalent of about 33 football pitches.

At Amwell Nature Reserve, there is just over two hectares of reedbed which the Trust manages with its many volunteers. In recent years, the Trust has secured funding from the Environment Agency to further help with the reserve's management, which has enabled contracted works requiring specialist equipment and training to improve the reedbeds. This has provided undisturbed places for Bittern to hunt with the hope that the birds would eventually breed there.  That vision came a step closer on 5 March 2024, when a male Bittern was recorded ‘booming’ (a mating call which sounds like the low pitched ‘hooo’ from blowing across the top of a bottle) for the first time at Amwell, signifying that the bird feels the habitat and food is good enough to consider trying to attract a mate there. Its booming has since been repeated and whilst a second bird has not been seen answering it yet, this is being noted as great progress by the wildlife charity and other local conservationists.

Tim Hill, Conservation Manager at Herts and Middlesex Wildlife Trust, says:

"In 1997, the Bittern was recorded at its lowest ebb with just 11 booming males left in the UK. Across the county, and with our partner organisations, guided by a dedicated Bittern conservation action plan, we have worked hard to create more reedbed habitat for these elusive, scarce and shy birds. It's fantastic for all concerned to see the reports of this breakthrough booming and clearly demonstrates that we can reverse the terrible declines we are seeing in our native wildlife, through conservation management and action.

“The Bittern is regarded as a key species which indicates the good health of reedbeds and the wider wetland ecosystem. We know from our ecological monitoring that the creation and conservation of reedy wetlands has not only benefited this bird but also a wealth of other rare wetland animals, including Water Voles, Otters and fish such as European Eels and Perch.

“You might wonder why a Bittern heard ‘booming at Amwell is important and relevant so let’s put that into context; The State of Nature report (2023) showed that one in six species is at risk of extinction, with that number climbing to 43% among bird species, so good news stories such as this one really do provide hope for the future of our ecosystem. Every species has a vital role and, at this critical point in the nature and climate crisis, we all want and need to strive for a liveable planet, where all species, including humans, can thrive.”

The Bittern is a well-camouflaged bird, with pale brown plumage, streaked with beige and black markings, distinctive yellow eyes, bony feet and a dagger-sharp beak. In contrast to it is more commonly seen cousin, the Grey Heron, the Bittern is shorter and more thick set. Back in time, when reedbeds were more prevalent, the Bittern was a common bird, hunted for the table and in East Anglia was known as the ‘fenmans’ roast!’. In keeping with its stocky appearance, the Bittern has a thick layer of fat – this was liked by cooks, who appreciated its self-basting quality, but thankfully, Bitterns are now protected by law and no longer make an appearance on the menu. The male’s ‘booming’ together with its love of wet reedbed habitat and its once common population in Norfolk and Suffolk, has earned the bird its nicknames of ‘bogblutter’ - and also ‘bull of the bog’ and ‘bog monster’. In Hertfordshire, Bitterns are now a frequent winter visitor to Amwell and have been sighted at Rye Meads and Marsworth Reservoir, but are yet to breed once again in the county. According to survey results from the RSPB and Natural England, published in 2023, there were 228 booming Bittern males counted in the 2022 breeding season – an increase of 1973% over 25 years. Amwell’s booming bird will now enhance those encouraging statistics further still.

Members of the public are welcome to try hearing the Bittern booming, by visiting the James Hide at Amwell Nature Reserve. The birds are likely to be most vocal at dawn during March and early April.

To find out more about how the Trust is managing the reedbed at Amwell Nature Reserve, to improve the habitat and support species like the Bittern, please read Dan Townsend, Senior Reserves Officer’s first-hand account here.