One of the rarest and most threatened of the UK’s birds, the first bittern of the winter has been spotted at RSPB Weymouth Wetlands.

One has been seen flying around at the Radipole Lake reserve in the middle of town while another has been sighted at the Lodmoor reserve off Preston Road.

Following an extensive restoration programme completed last year, it is hoped that more will join them to make the most of the wetlands’ better quality of habitat and increased supply of small fish and amphibians that they feed on.

“Last winter we had up to seven of these magnificent birds overwintering with us,” said Weymouth Wetlands warden Nick Quintrell. “They may have come from continental Europe or places closer to home like Norfolk or Somerset, where they breed.”

The bittern was common in the UK until a combination of persecution and loss of its reedbed habitat rendered it extinct here in the 1880s. It returned in 1911 but, struggling again, it looked as though it would disappear altogether as recently as the 1990s.

Concerted conservation efforts by the RSPB and others, particularly in acquiring, creating and restoring reedbeds like those at Weymouth Wetlands, are paying off. In monitoring numbers, conservationists listen out for the male’s booming call, which can carry up to 3km and has been likened to a foghorn or someone blowing across the top of a bottle. They boom – sometimes as early as January – to establish territory and attract females.

Now confined to southern England and Wales, a recent survey by the RSPB and Natural England found 104 booming males this year, up from just 11 in 1997.

“Although the bird remains on the red list, of high conservation concern, we’re definitely moving in the right direction,” added Nick, “and with the second stage of major restoration work at Weymouth Wetlands completed last winter, conditions have improved for bitterns here too.

“We’ve created more ditches and more open water and the shallow vegetated edges that have been formed are just the sorts of areas that bittern love to forage in for small fish and amphibians. And with wetter areas of reedbed, we’re hopeful that the bittern that overwinter with us now will stay and perhaps breed here within the next few years. When they do, it will be the first time in Dorset for more than 130 years.”

Weymouth Wetlands information officer Luke Phillips added: “It certainly is worth coming along for the chance of seeing one of these beautiful but extremely endangered birds. The best time of day to see them is late afternoon as they’re coming in to roost.”

The bittern is a stocky, thickset heron, smaller than the grey, with pale buff-brown plumage and dark streaks and bars – perfect camouflage for living in reedbeds.

If it’s alarmed, it will stretch its neck up, pointing its beak to the sky, looking even more like a reed itself. It will even ‘sway in the wind’ to complete the illusion.

You can find out more about what’s going on at RSPB Weymouth Wetlands’ at the blog at rspb.org.uk/ weymouthwetlandsblog