Dec. 11 (UPI) -- Police officials say they're at a complete loss to explain what caused the deaths of around 300 birds whose bodies were discovered littered across a rural British roadway.
The dead starlings were found Tuesday along a quiet country road on the island of Anglesey in Wales by local resident Hannah Stevens, and later filmed by her partner, Dafydd Edwards.
Stevens said she had seen the birds alive and well and flying in a massive flock when she first passed by the spot on her way to a doctor's appointment, but when she returned along the same route an hour later they were all dead.
Edwards then came out to film the incident.
"I counted 150 last night but I gave up as there's just hundreds of them littered everywhere," he said. "It's as if they just dropped down dead from the sky."
North Wales Police spokesman Rob Taylor said the cause of the birds' death was still a "complete mystery," adding that such incidents have happened before.
"We've ... sent some of the birds off for a toxicology and postmortem so I'm hoping we can get a result on that pretty soon but I would be very surprised if 300 died in one area without any of them being in the surrounding fields," he said.
The Royal Society for the Protection of Birds said it was "concerned," noting that starlings are an endangered species.
"We are keen to ensure the incident is investigated by the authorities, but for the time being it is important not to speculate on the cause," a spokesperson said.