Paula Talbot, who runs Northumberland and Borders Wildlife Rescue, received a call from a member of the public on the evening of Wednesday, May 11.
The woman told Paula that her daughter had witnessed a group of youths throwing stones at a herring gull in the Highcliffe area of Spittal earlier that evening and it was badly injured.
She took it in herself and then to Paula on the morning of Thursday, May 12. Despite her best efforts, the gull died on Saturday, May 14.
The injuries and death have been reported to wildlife crime officers at Northumbria Police.
Paula said: “When the gull arrived, he was in a very bad way and had huge bruises on his head.
“I provided pain relief, critical care fluids and kept him warm.
“He seemed to stabilise a little, but on Saturday morning he was screaming in pain and I had never heard anything like it. I did what I could and I was planning to take him to a vets, but sadly he passed away.”
She added: “Gulls are much maligned by some people in Berwick and there have been previous incidents where they have been targeted in Highcliffe.
“However, this stoning one was still shocking to me because it was a group of kids who apparently carried this out.”
Adult herring gulls have light grey backs, white under parts, and black wing tips with white ‘mirrors’.
Their legs are pink, with webbed feet, and they have slightly hooked bills marked with a red spot.
A Northumbria Police spokesperson said: “Our wildlife officers received a report of a concern for an animal at Highcliffe play park, Berwick.
“It was reported that a small group of pre-teens had been intentionally harming a seagull by throwing stones at it.
“The bird sadly died later from its injuries and inquiries are on-going to identify and locate anyone involved.
“Anyone with any information is asked to contact police via the ‘Tell Us Something’ page of our website using reference NP-20220518-0379.”