One of the world's loveliest herons, the great white egret, has nested in Britain for the first time, as new bird species continue to move here from the south, perhaps because of the warming climate.
A pair of the elegant, long-necked and long-legged waterbirds – a century ago, persecuted for their snow-white feathers which were used in women's hats – has set up home in the Avalon marshes near Glastonbury in Somerset, and the nest site, deep in a reed bed, is being monitored around the clock.
Activity on the site strongly suggests the birds may already have young and conservationists hope to confirm this soon, thus proving that Britain has added a new species to its list of breeding birds.
"This is hugely exciting and we've been keeping fingers crossed and a close eye on the nest since the signs of nesting activity were first noticed last month," said Simon Clarke, of Natural England, the Government's wildlife agency which runs Shapwick Heath National Nature Reserve, where the birds are nesting.
Great white egrets nest further south in Europe – the Somerset female was ringed as a chick in southern Brittany – but have been gradually moving northwards, and visiting birds have become more frequent in Britain, before finally taking the plunge and nesting.
In this they have followed a pattern seen in recent years in half a dozen species of the extended heron family, or to be precise, the order Ciconiiformes, which is the grouping containing herons, storks and spoonbills. All have moved into Britain from the south, and it is thought that they may have been drawn northwards by the warming climate (as well as by the care with which wetland wildlife sites are now managed in many parts of Britain).
The process began with the little egret, which first nested at Poole Harbour in Dorset in 1996 and has now spread so widely that there are hundreds of pairs nesting across the country. A closely related species, the cattle egret, nested for the first time in Britain in 2008, in Somerset.
In 2010 two more of the family arrived – the purple heron, which began to breed in Dungeness in Kent, and the little bittern, which nested, like the cattle egret and this year's great white egret, in the wetlands of Somerset, at Ham Wall Nature Reserve.
Accompanying them in 2010, on the other side of England, were more relatives – a group of spoonbills, which began to breed as a colony, for the first time in 300 years, at Holkham Nature Reserve on the north Norfolk coast.
The great white egret nest is being monitored round the clock by volunteers from Natural England, the RSPB and the Somerset Ornithological Society.
"The Avalon Marshes are a wonderful example of landscape scale conservation, where partnership working has produced one of Western Europe's largest and best wetlands," said the RSPB's Tony Whitehead. "Places such as these are vital in providing valuable space for newly colonising species as well as safeguarding populations of vulnerable birds such as bittern."
The RSPB and Natural England have set up an information line for people to keep up to date with the birds' progress on 07866 554142.
Breeding visitors: herons at home in Britain
Great white egret (Ardea alba)
Quite similar to the little egret. Shapwick Heath Nature Reserve, Somerset in 2012
Little egret (Egretta garzetta)
Small white heron with attractive white plumes. First bred in Poole Harbour, Dorset, in 1996.
Cattle egret (Bubulcus ibis)
Birds which often spend time close to livestock. First bred in Somerset, 2008.
Purple heron (Ardea purpurea)
Cousin of our own grey heron. First bred in Dungeness, Kent, in 2010.
Little bittern (Ixobrychus minutus)
A smaller version of our common bittern, suspected of breeding here but not proved until 1984, in Yorkshire.
Spoonbill (Platalea leucorodia)
Heron-like birds with spatulate, or spoon-shaped bills. Established at Holkham, Norfolk in 2010.