Staff at RSPB Lakenheath Fen have said it was fortunate the reserve's resident cranes had not returned to breed after two incidents of motorcyclists illegally riding near to nesting sites.

Eastern Daily Press: Little Ouse taken at RSPB Lakenheath Fen. Picture John Worrall.Little Ouse taken at RSPB Lakenheath Fen. Picture John Worrall. (Image: Archant)

There are fewer than 50 breeding pairs of cranes in the UK and the reserve on the Norfolk/Suffolk border is home to two resident breeding pairs.

Last year they raised three chicks between them for the second year in a row.

But two incidents last month of people found riding on dirt bikes on part of the reserve which is not accessible to the public, could have had disastrous consequences.

One of those incidents, on January 29, saw two men and a woman caught on a camera used to monitor wildlife riding dirt bikes.

Rupert Masefield, Eastern England communications officer for the RSPB, said: 'Fortunately, these incidents took place before the cranes returned to the reserve after spending the winter elsewhere in the Fens, where the birds gather in groups to feed and roost on farmland and wet grassland.

'Had these incidents occurred later in the year, when the cranes were back on the reserve and starting to prospect for nesting sites, the risk of disturbance would have been high.'

He added: 'This year, the first pair returned to the reserve in early February. The worst case scenario would be that the cranes could have abandoned their nesting attempt as a result of the disturbance.

'Given the very small number of breeding cranes in the UK – the majority of which are in The Fens and The Broads – this would have had a significant impact on the UK population of these birds.'

It is believed the motorcyclists gained access via a gated, key-pad locked level-crossing, which they should not have been able to open.

Sergeant Jason Francis, from Suffolk police, said: 'We are aware of reports of off-road bikers targeting parts of Lakenheath and are working closely with the council to crackdown on dangerous and illegal driving on private land. This remains ongoing.

'We ask members of the public to report any issues at the time and our officers will do their best to attend where possible. The public can help further by taking note of any vehicle registration details, along with a description of the vehicles and its occupants, and supply these to the local Safer Neighbourhood Team on brandon.snt@suffolk.pnn.police.uk.'

For more information about the reserve visit http://www.rspb.org.uk/