Research suggests that it will take more than a slew of "do not feed the birds" posters to keep gulls from swooping down to steal people's goodies.

According to research on herring gulls at Brighton Beach, the birds can figure out what types of crumbs are worth snatching by studying what humans eat.

When offered packs of chips to peck at, gulls overwhelmingly chose the same color bag that a researcher was nibbling on while filming the interactions from a distance of several yards.

Franziska Feist, a biologist and first author of the study at the University of Sussex stated, “We’ve shown that adult gulls are able to pay attention to the behavior of humans and apply that to their own foraging choices.” 

“Given that the urbanization of gulls is very recent, this ability must come from the gulls’ general smartness and behavioral flexibility.”

Scientists previously knew that gulls prefer human-touched food, but it was unknown just how much they use their observations of humans munching on foods to choose comparable morsels when foraging.

In their most recent project, Feist and her colleagues taped green (salt and vinegar) and blue (cheese and onion) Walkers chips packets to tiles and positioned them a few yards away from seabirds on an otherwise empty stretch of Brighton beach. The scientists then moved back 5 meters and recorded the birds' behavior. In some situations, the researchers just stared at the camera, while in others, they ate crisps from a green or blue bag.

Fewer than a quarter of the gulls approached the chips packets put nearby while the scientists sat calmly without munching. When the researchers were eating, however, 48% of the birds hopped over to inspect the packs.

Almost 40% of such attempts resulted in gulls pecking at the packs of chips, and 95% of them were aimed towards the same color packet that the scientist was eating from. “It is impressive because the evolutionary history of herring gulls wouldn’t have involved humans,” Feist added.

According to the findings, there is still work to be done to prevent conflict between people and urban gulls. The effect of "do not feed the birds" signage, for example, might be enhanced by including "... and don't let them see you eat, either."

Feist expressed that simply stopping the public from feeding birds may not be enough since they are able to observe what we eat.

According to Dr.Madeleine Goumas, an expert on herring gulls at Exeter University, previous research has already shown that gulls rely on information from people to search for food. However, she adds that gulls are also learning "what type of food we're eating. Knowing this may have implications for how we reduce negative interactions between humans and gulls, as we seem to be inadvertently teaching gulls to exploit new food items.”