Nature charities have warned of an impending disaster for some of the region's best-loved wildlife if the continued dry spell evolves into the predicted severe drought.

East Anglia is home to some of the UK's most important wetland sites for species including bitterns, bearded tits, otters and butterflies.

But the RSPB said some creatures would struggle to survive into the summer if consistent rain does not fall within the next few weeks.

Rob Coleman, site manager at the RSPB's Titchwell Marsh on the north Norfolk coast, said: 'Our natural springs at Titchwell have really slowed down, almost totally dried up, and this is a worrying time for us.

'At the moment, the water levels are good, we are adapting to the conditions and have a record number of wintering bitterns on the site. However, if these conditions continue, we will have to manage the habitat in a very different way to make up for the lack of water. This will put our iconic wildlife in a very vulnerable position.'

Ian Robinson, from the RSPB in the Broads said: 'The Broads is known for its lush, low, wet habitats and this lack of rainfall is alarming. At this time of year we normally have up to 35pc surface water flooding here on the reserves in the Yare valley, but we are currently at just 15pc.

'The grazing marshes on Berney Marshes is a refuge for breeding birds like lapwing and redshank, which rely heavily on this wet grassland. This habitat will not be ideal for them if the lack of rainfall continues and that will be disastrous for their breeding season.'

John Blackburn, Norfolk Wildlife Trust's reserve manager at Hickling Broad, said: 'There has been a very low winter water level in the Broads – the lowest I can remember in the 15 years I have been here.

'A site the size of Hickling has more resilience than those of just a couple of acres, so we're not panicking, but there are dykes around the marshes which are very dry. If there is no change in the ground water it will have an impact on the grazing marshes and that could affect the food supply for ground-nesting waders like lapwings. It all depends whether the doom and gloom in the predictions is correct.'

Darrell Stevens, NWT reserve manager for Breckland said: 'Cranberry Rough (near Great Hockham) is one of our greatest concerns because there are some rare sphagnum moss communities growing there which do not like it dry. 'They grow in floating rafts across the surface of the water. It has been quite dry for a while and we are not sure how long they will tolerate it.'

The Nene Washes in Cambridgeshire is another area struggling after two winters with little rainfall. Charlie Kitchin, RSPB site manager for the area, said: 'The breeding season of 2011 was not good at all for this nature reserve.

'Winter flooding is essential to attract the large numbers of wild swans and other wildfowl that the washes are renowned for and this winter has been the quietest for many years, for example our wigeon numbers are down from 20,000 to 3,000.'