A spate of swan deaths and injuries in one of East Anglia's most significant and sensitive wildlife areas has triggered the launch of a bird-strike survey that focuses on the effects of overhead power lines.

Eastern Daily Press: Looking down the beautiful Waveney valley from Bungay in the late afternoon sunlight. Photo: iwitness24.co.uk/Jane ClarkeLooking down the beautiful Waveney valley from Bungay in the late afternoon sunlight. Photo: iwitness24.co.uk/Jane Clarke (Image: (c) copyright citizenside.com)

At least four swans were found injured or dead in a four-week period earlier this year under or near power lines that crisscross the scenic Waveney Valley.

The incidents have led to the launch of a major survey throughout the valley - the snaking floodplain of the River Waveney which for parts of its length delineate the Suffolk-Norfolk border.

Waveney Bird Club, fresh from its triumph in the Wildlife and Landscape category of Suffolk's recent Creating the Greenest County Awards 2016, has launched the project in a bid to assess the scale of the bird-strike problem - and is keen to work in partnership with power company UK Power Networks if conservation action is found to be required.

Club project officer Paddy Shaw said club members and members of the wider public were being invited to survey stretches of the valley, from the source of the River Waveney near Redgrave and Lopham Fen to the wide estuarine landscape at Breydon Water, near Great Yarmouth.

'At various points along the valley overhead power lines cross the river floodplain or run parallel to it,' said Mr Shaw. 'We are not apportioning blame, we just want to ascertain as accurately as possible the extent of the problem and we are especially keen to work with the power company if we establish that any action needs to be taken.'

Swans appeared to be susceptible to cable collisions in the valley, he said. 'Mute swans are our heaviest birds and one of their problems is that they are not the most manoeuvrable of species.

'They are not that agile once they are in flight - they are not able to change direction very quickly. By the time they see the cables it seems almost inevitable that some will collide with them.

'The deaths and injuries that have been reported to us, and which seem to be caused by the power lines, have been appalling, although we are not challenging anyone or confronting anyone - we just want an amicable solution.'

The survey would record the presence or non-presence of bird diverters on power cables and record any bird corpses within 300 metres of the lines. Accuracy was essential, he said, and full location details were needed, along with species identification and ageing of any birds suspected of suffering a collision. Photographs would be 'extremely useful,' he said.

'We will be building up an accurate picture of power lines and their effects, assessing the effectiveness of bird diverters and seeing if there are any blackspots for bird strikes. We will then be in a position to discuss the data gathered with the power company,' Mr Shaw added.

Club chairman Steve Piotrowski said the Waveney Valley was a 'haven for wildlife.' Its broad floodplain contained marshes, some of which were designated nature reserves and all of which were important for many species. There were large areas of standing water throughout the valley and the combination of habitats made the area 'hugely significant' for wildlife and in landscape terms.

'The valley has abundant birdlife year-round, such as the mute swans whose numbers have increased but are now seeming to fall victim to the power lines, and it is also a known flyway for many migratory species, including Bewick's swans in late winter,' said Mr Piotrowski.

'This project is one in which the club feels it can make a difference to what appears to be a significant problem for birds using the valley.'

UK Power Networks said it would consider installing more bird diverters if the survey found problem areas.

It said: 'We were very concerned to hear about the death of swans near our overhead power lines. As an environmentally aware company we are committed to finding ways to limit the impact overhead lines have on the environment, while meeting our customers' needs for power.

'On average we install 30-40 bird diverters - orange discs about the size of a tea plate which are fixed onto overhead lines - a year across Suffolk and Norfolk and we recently installed them on overhead lines in Needham, Norfolk, after being alerted to a particular problem.

'If the group's survey highlights definite problem areas in the Waveney Valley, we will certainly look to install bird diverters there.'

For further information about the survey email projects@waveneybirdclub.com