Britain’s loudest bird has had a very successful breeding year, with 24% more male bitterns recorded doing their mating “booming” noise in 2023 compared with five years ago.
Conservationists for the RSPB recorded 234 males across England and Wales including at 11 new sites. The member of the heron family was mating in areas of new habitat created at the RSPB site Leighton Moss and on the Isle of Sheppey.
The birds are hard to spot, despite their large size, because they are secretive and successful at camouflaging themselves among reeds. However, during mating season the male birds make a distinctive “boom” noise to attract a mate. Each “boom” is different depending on which bird is making it, so the males can be counted by following their individual voices. The noise can be heard up to three miles away.
The birds are losing their reedbed habitats due to sea level rise caused by climate breakdown, so it is important that inland areas are created for them to breed in. They depend on areas with tall reeds and water so they can move, camouflaged, to hunt fish, insects and amphibians.
Bitterns became extinct as a breeding species in the UK in the 1870s as they were hunted for food and their habitat was drained for agriculture. They returned to Norfolk in 1900 but suffered another drop in numbers to just 11 booming males nationally by 1997 after more destruction of their habitat. New habitats have been created by conservationists to preserve the species.
As sea levels continue to rise due to the climate crisis, threatening the loss of valuable reedbed habitat in many coastal areas, these inland breeding sites will act as a refuge for bitterns and other wetland species. Restoring these habitats also helps to reduce downstream flooding risk and lock up carbon from the atmosphere.
Bitterns are still rare and confined to England and Wales, but were once found in Scotland and Northern Ireland. Conservationists hope they will re-establish themselves there in time.
