Egg collectors have been warned to 'think twice' before targeting wild bird nests in Norfolk.

RSPB senior investigations officer Mark Thomas said nature reserves across the county were being monitored to protect rare bird species.

It comes as around 5,000 wild bird eggs were seized from a property in Newton St Faith on Monday, May 21.

On the same day, a man in his 60s was arrested after being found with a 'clutch' of wild bird eggs at Cawston Heath, near Reepham.

Mr Thomas said egg collectors often stand out from other bird watchers.

He said:'They might have binoculars and a walking stick, and camouflaged clothing. It does not fit the profile of a bird watcher.

'They are quite secretive in the way they operate and they are exclusively male. We have never had a female.'

He said collectors take eggs directly from the nest and go to extreme lengths to get them.

Mr Thomas said: 'If you were a collector trying to target a marsh harrier in Norfolk, they would have to work out exactly where the birds are nesting.

'The collector would have to go out when they are less likely to get caught, and then wade out to a reed bed in waist-deep water.

'Even once they get to a nest, they would have to transport the egg without getting it damaged.

'Bearing in mind this happens in nature reserves which have staff looking out for things like this, it is very cat and mouse-like.'

He said Norfolk Police's Operation Compass was launched to target collectors.

'If there are collectors thinking of coming to Norfolk, then think again,' Mr Thomas said.

Under the Wildlife and Countryside Act 1981 it is illegal to possess wild bird eggs taken in contravention of the Protection of Birds Act 1954.

Mr Thomas said the eggs are not taken for their value, but because of the collector being 'obsessive'.

Police said they were called to Cawston Heath following reports of a man acting suspiciously this week. He was located by PC Colin Bailey and arrested after being found with the eggs.

His house was then searched, and eggs were found stored in wooden trays and catalogued.

Police said the man was arrested on suspicion of committing offences under the wildlife and countryside act.