Sixteen gulls have been found dead in a seaside resort within the past week, prompting the RSPCA to call for greater tolerance of the birds.
The bodies were found on grass verges and other areas around Seaford, near Eastbourne, East Sussex, following suspected shootings.
Inspectors said gulls are often viewed as pests but it is illegal to harm them as they are protected under the Wildlife and Countryside Act 1981.
RSPCA inspector Laura Bryant, who is leading an appeal for information about the attacks, said: "For there to be so many deaths in so short a time makes us think these poor gulls may be the victims of deliberate attacks, possibly shot.
"Shooting birds can cause a great deal of pain. Every year there are problems involving people attacking gulls and people need to remember that this is against the law.
"Gulls are as synonymous with the seaside as ice cream, but are all too often seen as a pest by people rather than part of the wildlife around them."
Last year, the RSPCA received 237 cruelty complaints about gulls, including reports of them being shot, having their nests destroyed and people throwing stones at them.
So far this year there have 135 similar complaints. A campaign has been launched by the charity's Mallydams Wood wildlife centre in Hastings to educate people about gulls.
Its manager, Bel Deering, said: "Lots of people, even animal lovers, have surprisingly fierce feelings against the poor old gull.
"They see them as pests and a nuisance rather than just opportunist creatures simply following the food source.
"We have hundreds of gulls in our centre in need of care every year. Sometimes the gulls are injured by natural causes, but others are definitely the victims of purposeful attacks, some of them shockingly savage."
The RSPCA said it believes deterrents and non-lethal methods of control are better at helping reduce problems associated with gulls, such as not feeding them and disposing of rubbish properly.