Animal welfare workers in eastern England are investigating how 1,000 day-old chicks became dumped in a field.

An inspector for the Royal Society for the Prevention of Cruelty to Animals said he’d “never seen anything like it,” after concerned passersby alerted him on Friday to the “sea of yellow” birds that someone had abandoned near Peterborough.

RSPCA The chicks were found abandoned in a field near Peterborough, in central England, on Friday.

“The chicks are only about a day old and are really tiny and quite delicate,” said the inspector, Justin Stubbs, in a written statement.

Sadly, he revealed that some of the birds were either already dead or in such bad health by the time of their discovery that they had to be put down.

“Thankfully, most of the chicks did not appear to be suffering,” he added.

RSPCA Volunteers pitched in to round the birds up into boxes so they could huddle for warmth.

With temperatures dipping, members of the public helped round up the birds into boxes so that they could huddle up for warmth.

RSPCA officials said they believed the chicks came from a nearby commercial chick producer and were abandoned “by a third-party.”

RSPCA Tragically, some of the birds had to be put down following their discovery.

The producer is helping the agency with its investigation and later collected the surviving birds, taking them back to their unit, officials said.

“These tiny birds wouldn’t have survived long out on their own at such a young age and in such unpredictable weather conditions,” Stubbs added. “For someone to dump these vulnerable chicks is unbelievable.”