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How to stop a gull from stealing your food

If you’ve ever been to the beach, you’ve probably also been here: afternoon sun beaming on your skin, waves crashing on the shore, and a hungry gull squawking as it swoops down to steal your sandwich. Such beach banditry may seem unavoidable, but new research has a solution: Staring down thieving gulls may make them think twice before snatching your food.

Herring gulls (Larus argentatus) are common in coastal cities and towns; their nests are on roofs instead of cliffs, and their food comes from the trash instead of the ocean. Gull-versus-human conflicts usually end in the death of the birds (from, for example, steel spikes that people install on rooftops). To understand how to protect the gulls—and save humans from headache—researchers tested whether the human gaze can affect bird behavior.

The researchers observed 74 herring gulls in coastal towns in Cornwall, U.K. They placed a transparent bag of potato chips in front of a human experimenter who was crouched close to the ground (see video). In one trial, the human looked directly at the bird and timed how long it took the bird to approach the bag. In another trial, the human looked away from the bird as it contemplated its next move. A trial was considered complete when the bird pecked the bag, or when the bag remained untouched for more than 5 minutes.

Of the 74 gulls, only 19 stayed in place long enough to complete both trials. It took the birds a median time of 25 seconds to peck the chips while being looked at, and just 13 seconds when free from a glaring eye. Although six birds refused to touch the food while being stared down, all of the birds deemed it safe to peck the chips when the human was looking away, researchers report today in Biology Letters.

The study suggests gulls find the human gaze terrifying—and that they take human behavior into account when trawling the city for meals. The researchers say changes in human behavior may save us a chip or two—and help guide more effective gull conservation efforts. So, next time a pesky gull tries to steal your food, don’t run away; try having a staring contest with it instead.