Want to Stop Gulls From Stealing Your Food? Stare Them Down, Study Says

“They are more likely to surprise you; they are more likely to attack from behind,” Ms. Ross-Smith said, as was the case with Mr. Fraser and his sandwich — although she said that calling such incidents attacks would be an overstatement. “It can feel like an attack to a person,” she said, “but they are not really attacks, just a bird feeding.”

She added that such occurrences were not common.

“We can also see it in the study — only some birds would attempt to take food,” Ms. Ross-Smith said, although she added that the incidents were more likely during peak tourist season, when there were “lots of potential candidates they can take food from.”

While the number of herring gulls in urban areas has increased, the species’ overall population in Britain appears to be in decline, with about 139,000 breeding pairs remaining, according to the Royal Society for the Protection of Birds, the country’s largest nature conservation charity. There are also around 110,000 pairs of lesser black-backed gulls in Britain, it estimates.

The conservation charity also suggests a tactic for defending against any gulls that come close: Move away, or raise your arms over your head. Waving your arms would agitate the birds, it advises.

There are legal restrictions on how gulls can be countered, however.

All gull species in Britain are protected under the Wildlife and Countryside Act 1981 and the Wildlife (Northern Ireland) Order 1985, making it illegal “to intentionally or, in Scotland and Northern Ireland, recklessly injure or kill any gull or damage or destroy an active nest or its contents,” the charity said on its website.

“However,” it added, “the law recognizes that in certain circumstances control measures may be necessary.”

In some cases, the charity said, licenses can be issued permitting the destruction of gull nests if no non-deadly solution is possible and if “it is done to prevent serious damage to agriculture, the spread of disease, to preserve public health and safety and air safety, or to conserve other wild birds.”