A man who built up an illegal hoard of nearly 4,000 rare bird eggs has been warned he is facing a jail sentence.
Daniel Lingham had the eggs in his caravan
Daniel Lingham, 52, of Newton St Faith, Norfolk, had the largest collection of nightingale and nightjar eggs found in the UK, Norwich magistrates heard.
Lingham admitted seven offences under the Wildlife and Countryside Act.
Magistrates adjourned sentencing until 16 March for reports but Lingham, who apologised for a "barbaric act of cruelty" was warned he could be jailed.
Officials from the Royal Society for the Protection of Birds said Lingham, a single, unemployed carpenter, had eggs belonging to some of the most protected species of wild bird in Britain.
They included the little tern, avocet, stone curlew, corncrake, black-tailed godwit, peregrine falcon, red-throated diver and chough.
Magistrates heard he kept his egg collection in the caravan where he lived.
RSPB investigator Mark Thomas said after the hearing that conservationists feared Lingham's activities might have damaged the population of nightingales in Norfolk.
"It was quite staggering finding nearly 4,000 birds' eggs in a caravan," Mr Thomas said after the hearing.
"Some of these birds are red listed, that means they are the most threatened birds in the UK.
It took a whole day to catalogue Lingham's hoard of eggs
"Here we have somebody who was prepared to target them and take their eggs every single month of the breeding season.
"We found more than 200 eggs belonging to either the nightingale or the nightjar and that is the largest number we have ever found in the UK."
Lingham admitted possessing wild bird eggs, possessing specially protected wild bird eggs, taking eggs from nests and possessing paraphernalia for collecting eggs, including egg blowing kits and padded containers.
James Landles, for Lingham, said his client had not intended to make money or wipe out wild bird populations.
He said Lingham had a love of the countryside and had been collecting eggs since he was a boy - a habit he had inherited from his father.
Mr Landles said Lingham now accepted that what he had done was barbaric and cruel.