Britain's loudest bird is making a comeback. The elusive bittern, once extinct in the UK, is now boasting its highest numbers since records began.
A relative of the more commonly seen grey heron, the highly secretive bitterns spend most of their time hidden in reed beds, making them incredibly difficult to survey by sight alone. Luckily for scientists, male bitterns have a unique booming call which they create by filling their gullets with air and then releasing it. This loud call can be heard from several kilometres away! Scientists from the Royal Society for the Protection of Birds (RSPB) and Natural England used the male bittern's distinctive mating call to track over 100 breeding males this summer. Increased numbers of the bittern represent a huge conservation success story. As recently as 1997 there were thought to be only 11 wild males left in the UK.
The population increase is principally due to intensive efforts by the RSPB and Natural England to restore the birds' reed-bed habitat. In a further reward for the hard-working researchers, the bitterns' range is expanding. Over the past two years, bitterns re-colonised the Somerset Levels, expanding their population from East Anglia and Norfolk. Bittern populations are growing in all three counties, a great achievement for wetland management in these counties.
Natural Environment Minister Richard Benyon said: "To see a species that was once extinct in the UK rise to a population of over one hundred is a real achievement. This is largely down to the work of the RSPB and Natural England, and shows what can be achieved if we work together."
Bitterns were once common in the UK, but by the 19th century their population was suffering a catastrophic decline. Hunting and habitat loss took their toll and in 1885 they were declared extinct in the UK. In the mid 20th Century bitterns re-colonised some areas of the UK, but further loss of their wetland habitat led to yet another population decline.
Martin Harper, RSPB's Conservation Director, said: "To lose the bittern once in Britain was regrettable, but to have lost it twice would have been unforgiveable"
Such a recovery for the bittern brings hope to conservationists working to save wetland species and shows that their habitat can be restored. However, in common with wetlands across the world, the UK habitat is still under threat along with the species that depend on it. One major threat is rising sea levels, which could have devastating impacts on the delicate freshwater wetlands found along the coast.
Nonetheless, the latest bittern research is an encouraging result for the birds and shows the power of cross-collaboration across a wide range of organisations and individuals.
Dr Pete Brotherton, Natural England's Head of Biodiversity said: "The bittern's recovery is a great conservation achievement and shows what can be done when government, conservationists and landowners work together. This is an encouraging sign that we can restore and improve our wetland habitats, which bring vital benefits to both people and wildlife."
Top Image Credit: Bittern and frog © MirrorSlap