Police have 'explanation' over Anglesey bird deaths mystery
Police believe they know what killed hundreds of starlings and said a similar incident occurred at the same spot about 12 years ago.
About 225 starlings were found with blood on their bodies on an Anglesey lane on Tuesday afternoon.
Dafydd Edwards, whose partner found the birds, said it was as if "they had dropped down dead from the sky".
PC Dewi Evans told BBC Radio 4: "We have actually been developing an explanation for what happened."
"It's a rational explanation, but we're not going to be revealing what we think the explanation is until such time as the investigation's complete," PC Evans, from North Wales Police's Rural Crime Team, said.
He said people had contacted the force with "all sorts of weird and wonderful theories".
"It's interesting because when you do research on this phenomenon... it seems to have happened on many occasions in the past.
"But what's particularly strange, if you will, about this case is that it seems that this exact phenomenon happened in the same spot about 12 years ago."
- Hundreds of dead birds found in mystery mass death
- Dozens of dead birds found floating in loch
- 'Disorientated' birds found dead in town
Mr Edwards, 41, said his partner Hannah Stevens first saw the birds alive as she went to an appointment.
"She said she saw hundreds of them flying over and thought it looked amazing but on her way back around an hour later they were all dead in the road."
What are starlings?
- Smaller than blackbirds, with a short tail, pointed head, triangular wings, starlings look black at a distance but when seen closer they are very glossy with a sheen of purples and greens
- Noisy birds, starlings spend a lot of the year in flocks
- They usually lay 4-6 eggs in mid-April
- Starlings are very tenacious and adaptable birds
- Over the centuries they have expanded their numbers and range in the wake of farmers, wherever suitable conditions became available. They used to be uncommon birds in the UK
- Starling numbers have declined markedly across much of northern Europe and the UK. The decline in the UK started during the early 1980s and has continued ever since
- Long-term monitoring shows starling numbers have fallen by 66% in Britain since the mid-1970s
The Animal and Plant Health Agency collected them for testing and will examine whether they could have been poisoned.
A spokesman for the RSPB said on Wednesday: "This is obviously very concerning for us and we will await the test results.
"It would be inappropriate for us to speculate as to how they have died."