Experts at Norfolk and Suffolk nature Meccas will be scrutinising changing environments to protect seabirds currently facing a three-pronged threat.

According to a National Trust study into issues affecting breeding at its 11 UK seabird sites, extremes such as last year's tidal surge and heavy rains of summer 2012 were the most prevalent threat.

After natural predators, it said the third most common risk was disturbance by humans, and urged nature reserve visitors to be aware of their potential impact on breeding season.

At Blakeney Point the surge altered areas where little terns, which arrived from west Africa in late March, bred.

The birds' breeding success was affected when June high tides flooded their new nests.

Ajay Tegala, coastal ranger at Blakeney, said: 'The biggest impact of the tidal surge was it changed the beach profile. It is important to protect the point for future generations. It is quite special.'

Out of the 110 little terns that bred this year, eight chicks fledged.

Last year there were 113 pairs which fledged 20 chicks and in 2012 there were 140 pairs which fledged 28 chicks.

Mr Tegala added: 'We are worried about the little terns' future because there are so many pressures on them. We don't want to interfere too much but have to do further things to stop them declining.'

Work includes monitoring breeding profiles, nests and putting in trail cameras.

More regular monitoring to detect changes in seabird colonies was recommended in the trust report.

Winterton became the largest single colony of little tern in the UK earlier this year when numbers soared to 300 breeding pairs from 100 last year.

But the impact of high tides and strong winds in July resulted in at least 260 dead birds.

RSPB warden Danny Hercock said: 'As the world becomes more developed, as wild space like beaches come under pressure, and as climate change takes effect, little terns need the support of people and actions from decision making bodies to recover their numbers and have safe places on our beaches.'

Orford Ness in Suffolk was listed in the 10 highest priority UK wildlife sites for breeding seabirds in the trust report.

Visitors to the site are sometimes asked to avoid areas to prevent disturbance.

A recent EU-funded LIFE+ project, carried out in partnership with the RSPB, reported that 2014 had been a successful year, highlighted by common terns fledging for the first time in 50 years.

LIFE+ project manager David Mason said the success was down to giving birds space from walkers.

He said: 'The success we have seen here this year is testament to what nature can achieve when it is encouraged to thrive.'

More fledging redshank and lapwing chicks have also been reported, three oystercatcher chicks are the first known to fledge since 2006 and avocets have had a productive year.

Kessingland was a key site for birds displaced by high tides, with a peak count of about 250 birds and 50 breeding pairs in mid-July.

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